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Pei K, Georgi M, Hill D, Lam CFJ, Wei W, Cordeiro MF. Review: Neuroprotective Nanocarriers in Glaucoma. Pharmaceuticals (Basel) 2024; 17:1190. [PMID: 39338350 DOI: 10.3390/ph17091190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 09/01/2024] [Accepted: 09/06/2024] [Indexed: 09/30/2024] Open
Abstract
Glaucoma stands as a primary cause of irreversible blindness globally, characterized by the progressive dysfunction and loss of retinal ganglion cells (RGCs). While current treatments primarily focus on controlling intraocular pressure (IOP), many patients continue to experience vision loss. Therefore, the research focus has shifted to therapeutic targets aimed at preventing or delaying RGC death and optic nerve degeneration to slow or halt disease progression. Traditional ocular drug administration, such as eye drops or oral medications, face significant challenges due to the eye's unique structural and physiological barriers, which limit effective drug delivery. Invasive methods like intravitreal injections can cause side effects such as bleeding, inflammation, and infection, making non-invasive delivery methods with high bioavailability very desirable. Nanotechnology presents a promising approach to addressing these limitations in glaucoma treatment. This review summarizes current approaches involving neuroprotective drugs combined with nanocarriers, and their impact for future use.
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Affiliation(s)
- Kun Pei
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Maria Georgi
- St Mary's Hospital, Imperial College Healthcare NHS Trust, London W2 1NY, UK
- Department of Surgery & Cancer, Imperial College London, London SW7 5NG, UK
| | - Daniel Hill
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | | | - Wei Wei
- Department of Surgery & Cancer, Imperial College London, London SW7 5NG, UK
- Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London NW1 5QH, UK
| | - Maria Francesca Cordeiro
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Department of Surgery & Cancer, Imperial College London, London SW7 5NG, UK
- Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London NW1 5QH, UK
- Western Eye Hospital, London NW1 5QH, UK
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Xuan M, Wang W, Bulloch G, Zhang J, Ha J, Wang Q, Wang J, Lin X, He M. Impact of Acute Ocular Hypertension on Retinal Ganglion Cell Loss in Mice. Transl Vis Sci Technol 2024; 13:17. [PMID: 38506800 PMCID: PMC10959197 DOI: 10.1167/tvst.13.3.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 02/07/2024] [Indexed: 03/21/2024] Open
Abstract
Purpose To assess the correlation between intraocular pressure (IOP) levels and retinal ganglion cell (RGC) loss across different fixed-duration episodes of acute ocular hypertension (AOH). Methods AOH was induced in Thy1-YFP-H transgenic mice by inserting a needle connected to a saline solution container into the anterior chamber. Thirty-one groups were tested, each comprising three to five mice exposed to IOP levels ranging from 50 to 110 mm Hg in 5/10 mm Hg increments for 60/90/120 minutes and a sham control group. The YFP-expressing RGCs were quantified by confocal scanning laser ophthalmoscopy, whereas peripapillary ganglion cell complex thickness was measured using spectral-domain optical coherence tomography. Changes in RGC count and GCCT were determined from values measured 30 days after AOH relative to baseline (before AOH). Results In the 60-minute AOH groups, RGC loss varied even when IOP was increased up to 110 mm Hg (36.8%-68.2%). However, for longer durations (90 and 120 minutes), a narrow range of IOP levels (60-70 mm Hg for 90-minute duration; 55-65 mm Hg for 120-minute duration) produced a significant difference in RGC loss, ranging from <25% to >90%. Additionally, loss of YFP-expressing RGCs was comparable to that of total RGCs in the same retinas. Conclusions Reproducible RGC loss during AOH depends on precise durations and IOP thresholds. In the current study, the optimal choice is an AOH protocol set at 70 mm Hg for a duration of 90 minutes. Translational Relevance This study can assist in determining the optimal duration and intensity of IOP for the effective utilization of AOH models.
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Affiliation(s)
- Meng Xuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Wei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Gabriella Bulloch
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Faculty of Science, Medicine and Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Jian Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Jason Ha
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Qilin Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Juanjuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Xingyan Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Mingguang He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), Hong Kong, China
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Sharif NA. Identifying new drugs and targets to treat rapidly elevated intraocular pressure for angle closure and secondary glaucomas to curb visual impairment and prevent blindness. Exp Eye Res 2023; 232:109444. [PMID: 36958427 DOI: 10.1016/j.exer.2023.109444] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/23/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
A multitude of pharmacological compounds have been shown to lower and control intraocular pressure (IOP) in numerous species of animals and human subjects after topical ocular dosing or via other routes of administration. Most researchers have been interested in finding drug candidates that exhibit a relatively long duration of action from a chronic therapeutic use perspective, for example to treat ocular hypertension (OHT), primary open-angle glaucoma and even normotensive glaucoma. However, it is equally important to seek and characterize treatment modalities which offer a rapid onset of action to help provide fast relief from quickly rising IOP that occurs in certain eye diseases. These include acute angle-closure glaucoma, primary angle-closure glaucoma, uveitic and inflammatory glaucoma, medication-induced OHT, and other secondary glaucomas induced by eye injury or infection which can cause partial or complete loss of eyesight. Such fast-acting agents can delay or prevent the need for ocular surgery which is often used to lower the dangerously raised IOP. This research survey was therefore directed at identifying agents from the literature that demonstrated ocular hypotensive activity, normalizing and unifying the data, determining their onset of action and rank ordering them on the basis of rapidity of action starting within 30-60 min and lasting up to at least 3-4 h post topical ocular dosing in different animal species. This research revealed a few health authority-approved drugs and some investigational compounds that appear to meet the necessary criteria of fast onset of action coupled with significant efficacy to reduce elevated IOP (by ≥ 20%, preferably by >30%). However, translation of the novel animal-based findings to the human conditions remains to be demonstrated but represent viable targets, especially EP2-receptor agonists (e.g. omidenepag isopropyl; AL-6598; butaprost), mixed activity serotonin/dopamine receptor agonists (e.g. cabergoline), rho kinase inhibitors (e.g. AMA0076, Y39983), CACNA2D1-gene product inhibitors (e.g. pregabalin), melatonin receptor agonists, and certain K+-channel openers (e.g. nicorandil, pinacidil). Other drug candidates and targets were also identified and will be discussed.
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Affiliation(s)
- Najam A Sharif
- Institute of Ophthalmology, University College London (UCL), London, UK; Imperial College of Science and Technology, St. Mary's Campus, London, UK; Eye-ACP Duke-National University of Singapore Medical School, Singapore; Singapore Eye Research Institute (SERI), Singapore; Department of Pharmacy Sciences, Creighton University, Omaha, NE, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA; Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, Texas, USA; Ophthalmology Innovation Center, Santen Inc USA, Emeryville, CA, USA.
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Garner MA, Strickland RG, Girkin CA, Gross AK. Mechanisms of retinal ganglion cell injury following acute increases in intraocular pressure. FRONTIERS IN OPHTHALMOLOGY 2022; 2:1007103. [PMID: 38983517 PMCID: PMC11182138 DOI: 10.3389/fopht.2022.1007103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/26/2022] [Indexed: 07/11/2024]
Abstract
The maintenance of intraocular pressure (IOP) is critical to preserving the pristine optics required for vision. Disturbances in IOP can directly impact the optic nerve and retina, and inner retinal injury can occur following acute and chronic IOP elevation. There are a variety of animal models that have been developed to study the effects of acute and chronic elevation of IOP on the retina, retinal ganglion cell (RGC) morphology, intracellular signaling, gene expression changes, and survival. Acute IOP models induce injury that allows for the study of RGC response to well characterized injury and potential recovery. This review will focus on the initial impact of acute IOP elevation on RGC injury and recovery as these early responses may be the best targets for potential therapeutic interventions to promote RGC survival in glaucoma.
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Affiliation(s)
- Mary Anne Garner
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ryan G. Strickland
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christopher A. Girkin
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Alecia K. Gross
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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Fukui T, Tateno H, Nakamura T, Yamada Y, Sato Y, Iwasaki N, Harashima H, Kadoya K. Retrograde Axonal Transport of Liposomes from Peripheral Tissue to Spinal Cord and DRGs by Optimized Phospholipid and CTB Modification. Int J Mol Sci 2022; 23:6661. [PMID: 35743104 PMCID: PMC9223829 DOI: 10.3390/ijms23126661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
Despite recent advancements in therapeutic options for disorders of the central nervous system (CNS), the lack of an efficient drug-delivery system (DDS) hampers their clinical application. We hypothesized that liposomes could be optimized for retrograde transport in axons as a DDS from peripheral tissues to the spinal cord and dorsal root ganglia (DRGs). Three types of liposomes consisting of DSPC, DSPC/POPC, or POPC in combination with cholesterol (Chol) and polyethylene glycol (PEG) lipid were administered to sciatic nerves or the tibialis anterior muscle of mature rats. Liposomes in cell bodies were detected with infrared fluorescence of DiD conjugated to liposomes. Three days later, all nerve-administered liposomes were retrogradely transported to the spinal cord and DRGs, whereas only muscle-administered liposomes consisting of DSPC reached the spinal cord and DRGs. Modification with Cholera toxin B subunit improved the transport efficiency of liposomes to the spinal cord and DRGs from 4.5% to 17.3% and from 3.9% to 14.3% via nerve administration, and from 2.6% to 4.8% and from 2.3% to 4.1% via muscle administration, respectively. Modification with octa-arginine (R8) improved the transport efficiency via nerve administration but abolished the transport capability via muscle administration. These findings provide the initial data for the development of a novel DDS targeting the spinal cord and DRGs via peripheral administration.
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Affiliation(s)
- Takafumi Fukui
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo 060-8638, Japan; (T.F.); (N.I.)
| | - Hironao Tateno
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan; (H.T.); (Y.Y.); (Y.S.); (H.H.)
| | - Takashi Nakamura
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan; (H.T.); (Y.Y.); (Y.S.); (H.H.)
| | - Yuma Yamada
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan; (H.T.); (Y.Y.); (Y.S.); (H.H.)
| | - Yusuke Sato
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan; (H.T.); (Y.Y.); (Y.S.); (H.H.)
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo 060-8638, Japan; (T.F.); (N.I.)
| | - Hideyoshi Harashima
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan; (H.T.); (Y.Y.); (Y.S.); (H.H.)
| | - Ken Kadoya
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo 060-8638, Japan; (T.F.); (N.I.)
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Dias MS, Luo X, Ribas VT, Petrs-Silva H, Koch JC. The Role of Axonal Transport in Glaucoma. Int J Mol Sci 2022; 23:ijms23073935. [PMID: 35409291 PMCID: PMC8999615 DOI: 10.3390/ijms23073935] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Glaucoma is a neurodegenerative disease that affects the retinal ganglion cells (RGCs) and leads to progressive vision loss. The first pathological signs can be seen at the optic nerve head (ONH), the structure where RGC axons leave the retina to compose the optic nerve. Besides damage of the axonal cytoskeleton, axonal transport deficits at the ONH have been described as an important feature of glaucoma. Axonal transport is essential for proper neuronal function, including transport of organelles, synaptic components, vesicles, and neurotrophic factors. Impairment of axonal transport has been related to several neurodegenerative conditions. Studies on axonal transport in glaucoma include analysis in different animal models and in humans, and indicate that its failure happens mainly in the ONH and early in disease progression, preceding axonal and somal degeneration. Thus, a better understanding of the role of axonal transport in glaucoma is not only pivotal to decipher disease mechanisms but could also enable early therapies that might prevent irreversible neuronal damage at an early time point. In this review we present the current evidence of axonal transport impairment in glaucomatous neurodegeneration and summarize the methods employed to evaluate transport in this disease.
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Affiliation(s)
- Mariana Santana Dias
- Intermediate Laboratory of Gene Therapy and Viral Vectors, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (M.S.D.); (H.P.-S.)
| | - Xiaoyue Luo
- Department of Neurology, University Medical Center Göttingen, 37077 Göttingen, Germany;
| | - Vinicius Toledo Ribas
- Laboratory of Neurobiology, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Hilda Petrs-Silva
- Intermediate Laboratory of Gene Therapy and Viral Vectors, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (M.S.D.); (H.P.-S.)
| | - Jan Christoph Koch
- Department of Neurology, University Medical Center Göttingen, 37077 Göttingen, Germany;
- Correspondence:
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Tribble JR, Otmani A, Kokkali E, Lardner E, Morgan JE, Williams PA. Retinal Ganglion Cell Degeneration in a Rat Magnetic Bead Model of Ocular Hypertensive Glaucoma. Transl Vis Sci Technol 2021; 10:21. [PMID: 33510960 PMCID: PMC7804499 DOI: 10.1167/tvst.10.1.21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/02/2020] [Indexed: 01/22/2023] Open
Abstract
Purpose Glaucoma remains a leading cause of irreversible blindness worldwide. Animal glaucoma models replicate high intraocular pressure, a risk factor for glaucoma, to induce retinal ganglion cell (RGC) degeneration. We describe an inducible, magnetic bead model in the Brown Norway rat in which we are able to determine degeneration across multiple RGC compartments at a time point that is appropriate for investigating neurodegenerative events and potential treatment effects. Methods We induced ocular hypertension through injection of magnetic microspheres into the anterior chamber of Brown Norway rats; un-operated (naïve) rats served as controls. Intraocular pressure was recorded, and eye diameter measurements were taken before surgery and at the terminal end points. We assessed RGC degeneration and vascular changes through immunofluorescence, and axon transport to terminal brain thalami through intravitreal injection of fluorophore-conjugated cholera toxin subunit β. Results We observed clinically relevant features of disease accompanying RGC cell somal, axonal, and dendritic loss. RGC axonal dysfunction persisted along the trajectory of the cell into the terminal brain thalami, with clear disruption at the optic nerve head. We also observed vascular compromise consistent with human disease, as well as an expansion of global eye size with ocular hypertension. Conclusions The magnetic bead model in the Brown Norway rat recapitulates many clinically relevant disease features of human glaucoma, including degeneration across multiple RGC compartments. Eye expansion is likely a result of rodent scleral elasticity, and we caution that this should be considered when assessing retinal density measurements. Translational Relevance This model offers a disease-relevant platform that will allow for assessment of glaucoma-relevant therapeutics.
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Affiliation(s)
- James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Amin Otmani
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Eirini Kokkali
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Emma Lardner
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK.,School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
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LIU YUSHU, MA LIPING, GAO WEI, LIU ZHICHENG, WANG SHOUXIN, LIU LIU, GUO XUEQIAN, QIAN XIUQING, LI LIN. THE INFERENCE OF THE CHANGES OF AXONAL TRANSPORT OF OPTIC NERVE BY DEFORMATIONS OF LAMINA CRIBROSA. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519420400278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Understanding the relationship between the changes in the axonal transport of the optic nerve (ON) and lamina cribrosa (LC) deformation will be helpful to estimate the degree of axonal transport block by measuring the LC deformation in vivo. First, the changes in the axonal transport of the ON were studied using an acute high intraocular pressure (IOP) model, which was established by perfusing saline water into the anterior chamber of cats. The IOP of cat was unilaterally elevated to and maintained at 30, 40, and 50[Formula: see text]mmHg. The axonal transport of the ON was examined by confocal laser scanning microscope. Then the deformations and stress distributions of the LC and ON were calculated using a three-dimensional finite element model of the LC microstructure including ON. The results showed axonal transport changes of ON increased with elevation of the IOPs. While Young’s modulus of the LC and ON were assumed as 0.1[Formula: see text]MPa and 0.03[Formula: see text]MPa, the numerical simulation results showed that LC had displacements of 0.02, 0.03, and 0.04[Formula: see text]mm backward at the IOPs of 30, 40, and 50[Formula: see text]mmHg, respectively. The calculated compressive strain applied to the ON were 0.0425, 0.0567, and 0.0709 under 30, 40, and 50[Formula: see text]mmHg IOP, respectively. The results of strain and stress analysis of LC and ON showed that the deformation of LC would compress the ON. The axonal transport abnormalities could be inferred by measuring the LC deformation in vivo.
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Affiliation(s)
- YUSHU LIU
- Beijing Key Laboratory of Fundamental, Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, P. R. China
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIPING MA
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - WEI GAO
- Handan Central Hospital, Handan, Hebei 056001, P. R. China
| | - ZHICHENG LIU
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - SHOUXIN WANG
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIU LIU
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - XUEQIAN GUO
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - XIUQING QIAN
- Beijing Key Laboratory of Fundamental, Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, P. R. China
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIN LI
- Beijing Key Laboratory of Fundamental, Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, P. R. China
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
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Ahmed OM, Waisbourd M, Spaeth GL, Katz LJ. Improvement in structure and visual function in patients with glaucoma: the possible key to better treatment? Surv Ophthalmol 2020; 66:644-652. [PMID: 33316283 DOI: 10.1016/j.survophthal.2020.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/01/2020] [Accepted: 12/07/2020] [Indexed: 11/26/2022]
Abstract
Glaucoma is characterized by retinal ganglion cell loss that can lead to permanent visual loss. Current clinical management practice assumes that glaucomatous visual loss is irreversible; however, there is increasing evidence that permanent vision loss and cell death are preceded by reversible functional and structural changes. We propose that these changes should be considered by glaucoma specialists when treating their patients. We discuss the neurobiological basis of this phenomenon and provide clinical evidence of reversibility in both structure and function. Specifically, we review the findings of visual field testing, contrast sensitivity, electroretinography, and imaging of the optic nerve and their correlation with functional changes. We then discuss the clinical value of these observations in helping guide approaches toward the diagnosis and treatment of patients with glaucoma.
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Affiliation(s)
- Osama M Ahmed
- Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA; Yale University School of Medicine, New Haven, CT, USA
| | - Michael Waisbourd
- Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA; Department of Ophthalmology, Tel Aviv Medical Center, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - George L Spaeth
- Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | - L Jay Katz
- Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA.
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Berdahl JP, Ferguson TJ, Samuelson TW. Periodic normalization of the translaminar pressure gradient prevents glaucomatous damage. Med Hypotheses 2020; 144:110258. [PMID: 33254565 DOI: 10.1016/j.mehy.2020.110258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/30/2020] [Accepted: 09/05/2020] [Indexed: 01/02/2023]
Abstract
The 24-hour intraocular pressure (IOP) rhythm is of interest to clinicians but its overall impact on glaucomatous progression remains unclear. Recent evidence has implicated the translaminar pressure gradient (TLPG), or imbalance between IOP and intracranial pressure, in the development of glaucoma. Evidence suggests that retinal ganglion cell death occurs as a result of decreased axonal transport only after a sustained, elevated TLPG. We hypothesize that periodic normalization of the TLPG prevents glaucomatous damage by enabling temporary resumption of axonal transport. Temporary resumption of axonal transport allows for delivery of critical metabolic cargoes with concomitant removal of metabolic waste which prevents apoptosis of the retinal ganglion cell.
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11
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Chen AX, Greenlee TE, Conti TF, Briskin IN, Singh RP. Fluctuations in Macular Thickness in Patients with Retinal Vein Occlusion Treated with Anti-Vascular Endothelial Growth Factor Agents. Ophthalmol Retina 2020; 4:1158-1169. [PMID: 32480014 DOI: 10.1016/j.oret.2020.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/14/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
PURPOSE To evaluate macular thickness fluctuations in patients with retinal vein occlusions (RVOs) treated with anti-vascular endothelial growth factor (VEGF) agents and to assess whether patients with larger fluctuations have poorer visual outcomes. DESIGN Retrospective cohort study. PARTICIPANTS Treatment-naive patients with RVO. METHODS Central subfield thickness (CST), cube volume (CV), and cube average thickness (CAT) were collected from OCT images obtained at baseline and 3, 6, 9, and 12 months, and standard deviations (SDs) across 12 months were calculated. Mixed-effects regression was performed to examine the relationship between macular thickness SD and 12-month visual acuity (VA). Standard multiple regression was performed to identify predictors of macular thickness SD. MAIN OUTCOME MEASURES Standard deviations across 12 months for CST, CV, and CAT and VA at 12 months. RESULTS One hundred thirty-four eyes, including 71 with branch RVO (BRVO) and 63 with central RVO (CRVO), were evaluated. Mean baseline and 12-month CST were 488.6 ± 165.0 μm and 334.3 ± 131.9 μm (change, -154.3 ± 210.2 μm; P < 0.001), with CST SD of 114.1 ± 77.0 μm. Baseline and 12-month VA were 52.8 ± 20.9 letters and 65.9 ± 17.3 letters (change, +13.1 ± 20.3 letters; P < 0.001). Central subfield thickness SD was a significant negative predictor of 12-month VA (-5.21 letters/100 μm; 95% confidence interval [CI], -10.21 to -0.22 letters/100 μm; P = 0.041) when adjusting for baseline factors and injections. Baseline CST and number of injections were not predictive (P ≥ 0.101). Stratification by CST SD demonstrated a 10-letter difference in 12-month VA between the first and fourth quartiles. Baseline CST and RVO diagnosis were the only significant predictors of CST SD (CRVO vs. BRVO: +34.64 μm/100 μm [95% CI, 29.33-39.94 μm/100 μm; P < 0.001] and +22.13 μm/100 μm [95% CI, 4.81-39.44 μm/100 μm; P = 0.013]). Associations using CV and CAT were similar. CONCLUSIONS Larger macular thickness fluctuations are associated with poorer visual outcomes in patients with RVO treated with anti-VEGF agents. Macular thickness fluctuations, in addition to absolute macular thickness, may be an important prognostic biomarker in these patients.
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Affiliation(s)
- Andrew X Chen
- Case Western Reserve University School of Medicine, Cleveland, Ohio; Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio
| | - Tyler E Greenlee
- Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio
| | - Thais F Conti
- Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio
| | - Isaac N Briskin
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio
| | - Rishi P Singh
- Case Western Reserve University School of Medicine, Cleveland, Ohio; Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio.
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12
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Gilmore CS, Lim KO, Garvin MK, Wang JK, Ledolter J, Fenske AL, Gentz CL, Nellis J, Armstrong MT, Kardon RH. Association of Optical Coherence Tomography With Longitudinal Neurodegeneration in Veterans With Chronic Mild Traumatic Brain Injury. JAMA Netw Open 2020; 3:e2030824. [PMID: 33351088 PMCID: PMC7756235 DOI: 10.1001/jamanetworkopen.2020.30824] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
IMPORTANCE Mild traumatic brain injury (TBI) may predispose individuals to progressive neurodegeneration. OBJECTIVE To identify evidence of neurodegeneration through longitudinal evaluation of changes in retinal layer thickness using optical coherence tomography in veterans with a history of mild TBI. DESIGN, SETTING, AND PARTICIPANTS This longitudinal cohort study evaluated veterans who were receiving services at the Minneapolis Veterans Affairs Health Care System. Symptomatic or mild TBI was diagnosed according to the Mayo TBI Severity Classification System. Participants in the age-matched control group had no history of TBI. Participants with any history or evidence of retinal or optic nerve disease that could affect retinal thickness were excluded. Data analysis was performed from July 2019 to February 2020. EXPOSURES The presence and severity of mild TBI were determined through consensus review of self-report responses during the Minnesota Blast Exposure Screening Tool semistructured interview. MAIN OUTCOMES AND MEASURES Change over time of retinal nerve fiber layer (RNFL) thickness. RESULTS A total of 139 veterans (117 men [84%]; mean [SD] age, 49.9 [11.1] years) were included in the study, 69 in the TBI group and 70 in the control group. Veterans with mild TBI showed significantly greater RNFL thinning compared with controls (mean [SE] RNFL slope, -1.47 [0.24] μm/y vs -0.31 [0.32] μm/y; F1,122 = 8.42; P = .004; Cohen d = 0.52). Functionally, veterans with mild TBI showed greater declines in visual field mean deviation (mean [SE] slope, -0.09 [0.14] dB/y vs 0.46 [0.23] dB/y; F1,122 = 4.08; P = .046; Cohen d = 0.36) and pattern standard deviation (mean [SE] slope, 0.09 [0.06] dB/y vs -0.10 [0.07] dB/y; F1,122 = 4.78; P = .03; Cohen d = 0.39) and high spatial frequency (12 cycles/degree) contrast sensitivity compared with controls. Cognitively, there was a significantly greater decrease in the number of errors over time during the Groton Maze Learning Test (GMLT) in controls compared with veterans with mild TBI (mean [SE] slope, -9.30 [1.48] errors/y vs -5.23 [1.24] errors/y; F1,127 = 4.43; P = .04; Cohen d = 0.37). RNFL tissue loss was significantly correlated with both worsening performance on the GMLT over time (Spearman ρ = -0.20; P = .03) and mild TBI severity (Spearman ρ = -0.25; P = .006). The more severe the mild TBI (larger Minnesota Blast Exposure Screening Tool severity score), the faster the reduction in RNFL thickness (ie, the more negative the slope) across time. CONCLUSIONS AND RELEVANCE This cohort study found longitudinal evidence for significant, progressive neural degeneration over time in veterans with mild TBI, as indicated by greater RNFL tissue loss in patients with mild TBI vs controls, as well as measures of function. These results suggest that these longitudinal measures may be useful biomarkers of neurodegeneration. Changes in this biomarker may provide early detection of subsequent cognitive and functional deficits that may impact veterans' independence and need for care.
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Affiliation(s)
- Casey S. Gilmore
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Kelvin O. Lim
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
- Department of Psychiatry, University of Minnesota, Minneapolis
| | - Mona K. Garvin
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
| | - Jui-Kai Wang
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
| | - Johannes Ledolter
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
- Department of Business Analytics and Department of Statistics and Actuarial Science, University of Iowa, Iowa City
| | - Alicia L. Fenske
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Carolyn L. Gentz
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Julie Nellis
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
| | - Michael T. Armstrong
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Randy H. Kardon
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
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13
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Dave TV, Laghmisetty S, Krishnamurthy G, Bejjanki K, Ganguly A, Jonnadula GB, Dave VP, Reddy Pappuru R. Retinal vascularity, nerve fiber, and ganglion cell layer thickness in thyroid eye disease on optical coherence tomography angiography. Orbit 2020; 41:170-177. [PMID: 33198545 DOI: 10.1080/01676830.2020.1846761] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Purpose: To compare the retinal vascularity, peripapillary vascularity, nerve fiber layer thickness and ganglion cell layer thickness between active, inactive thyroid eye disease (TED) and healthy eyes.Methods: Retrospective comparative cross-sectional cohort study. Patients with TED, active and inactive on the VISA score, and healthy eyes were included. All patients underwent optical coherence tomography angiography with detailed demographic and clinical data capture. Using automated software, retinal and peripapillary vascularity index, nerve fiber layer thickness, and ganglion cell layer thickness were calculated and were compared between the groups.Results: Twenty-four eyes with active TED, 102 eyes with inactive TED and 52 healthy eyes were included. Independent sample t test was used to compare parametric data and Mann-Whitney test to compare non-parametric data. The age and gender were comparable across groups. The peripapillary vascularity index (26.82 ± 4.13 versus 34.92 ± 5.08, p = .002) and the macular vascularity index (20.32 ± 2.5 versus 31.21 ± 3.89, p < .0001) were reduced in active TED eyes versus inactive eyes. Macular vascularity index was comparable in the inactive versus the healthy eyes. The RNFL thickness was increased in the active TED eyes versus the inactive eyes (45.11 ± 18.3 versus 35.55 ± 7, p = .03) and active versus healthy eyes (45.11 ± 18.3 versus 36.28 ± 7.89, p = .03). Ganglion cell layer thickness between all three groups was comparable.Conclusion: Decrease in peripapillary and macular vascular density and increase in RNFL thickness are seen in active TED compared to inactive TED and healthy eyes. In disease inactivity, these parameters are comparable to healthy eyes.
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Affiliation(s)
- Tarjani Vivek Dave
- Ophthalmic Plastic Surgery Service, LV Prasad Eye Institute, Hyderabad, India
| | - Srujana Laghmisetty
- Ophthalmic Plastic Surgery Service, LV Prasad Eye Institute, Hyderabad, India
| | | | - Kavya Bejjanki
- Ophthalmic Plastic and Facial Aesthetic, Orbit and Ocular Oncology, LV Prasad Eye Institute, Vijaywada, India
| | - Anasua Ganguly
- Ophthalmic Plastic and Facial Aesthetic, Orbit and Ocular Oncology, LV Prasad Eye Institute, Vijaywada, India
| | | | - Vivek Pravin Dave
- Kanuri Santhamma Center for Vitreo-retinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Rajeev Reddy Pappuru
- Kanuri Santhamma Center for Vitreo-retinal Diseases, LV Prasad Eye Institute, Hyderabad, India
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14
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Gallego-Ortega A, Norte-Muñoz M, Miralles de Imperial-Ollero JA, Bernal-Garro JM, Valiente-Soriano FJ, de la Villa Polo P, Avilés-Trigueros M, Villegas-Pérez MP, Vidal-Sanz M. Functional and morphological alterations in a glaucoma model of acute ocular hypertension. PROGRESS IN BRAIN RESEARCH 2020; 256:1-29. [PMID: 32958209 DOI: 10.1016/bs.pbr.2020.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
To study short and long-term effects of acute ocular hypertension (AOHT) on inner and outer retinal layers, in adult Sprague-Dawley rats AOHT (87mmHg) was induced for 90min and the retinas were examined longitudinally in vivo with electroretinogram (ERG) recordings and optical coherent tomography (OCT) from 1 to 90 days (d). Ex vivo, the retinas were analyzed for rod (RBC) and cone (CBC) bipolar cells, with antibodies against protein kinase Cα and recoverin, respectively in cross sections, and for cones, horizontal (HZ) and ganglion (RGC) cells with antibodies against arrestin, calbindin and Brn3a, respectively in wholemounts. The inner retina thinned progressively up to 7d with no further changes, while the external retina had a normal thickness until 30d, with a 20% thinning between 30 and 90d. Functionally, the a-wave showed an initial reduction by 24h and a further reduction from 30 to 90d. All other main ERG waves were significantly reduced by 1d without significant recovery by 90d. Radial sections showed a normal population of RBCs but their terminals were reduced. The CBCs showed a progressive decrease with a loss of 56% by 30d. In wholemount retinas, RGCs diminished to 40% by 3d and to 16% by 30d without further loss. Cones diminished to 58% and 35% by 3 and 7d, respectively and further decreased between 30 and 90d. HZs showed normal values throughout the study. In conclusion, AOHT affects both the inner and outer retina, with a more pronounced degeneration of the cone than the rod pathway.
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Affiliation(s)
- Alejandro Gallego-Ortega
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - María Norte-Muñoz
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | | | - José Manuel Bernal-Garro
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Francisco Javier Valiente-Soriano
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Pedro de la Villa Polo
- Department of Systems Biology, University of Alcalá, Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain
| | - Marcelino Avilés-Trigueros
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - María Paz Villegas-Pérez
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Manuel Vidal-Sanz
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.
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15
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PENG FAN, MA LIPING, LIU LIU, LI LIN, QIAN XIUQING. PRELIMINARY STUDY ON THE BLOCKADE OF AXONAL TRANSPORT BY ACTIVATED ASTROCYTES IN OPTIC NERVE HEAD UNDER CHRONIC OCULAR HYPERTENSION. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419400402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glaucoma is considered a group of neurodegenerative diseases that damage the optic disc and result in a reduction of the field of vision. High intraocular pressure-induced deformation of optic nerve head (ONH) may compress the optic nerve and affect axonal transport. This study aims to show experimental observations: the activated astrocytes under high intraocular pressure play an important role in compression of optic nerve and block of axonal transport. Four-week duration of ocular hypertension (more than 20[Formula: see text]mm Hg) rats induced by cauterizing of three episcleral vessels and administering a fluorouracil subconjunctival injection in the right eye were enrolled and the left eyes of all the rats were used as a self-control. The axonal transport of the optic nerve was examined by a confocal laser scanning microscope after intravitreally injecting rhodamine-[Formula: see text]-isothiocyanate. The morphology of the optic nerve head was examined by hematoxylin–eosin (HE) staining, immunofluorescence staining and transmission electron microscopy (TEM). The results showed transport of rhodamine-[Formula: see text]-isothiocyanate was blocked in the experimental group, and fluorescent dye accumulated around the ONH. The nucleus counts of the coronal section kidney-shaped area showed that the number of cell nucleus in experimental eye was more than that of the control according to the results of HE staining. The increased collagen fibers in ONH were observed. The density of the glial fibrillary acidic protein in experimental eyes was a little bit higher than that in the control group by quantify analysis of the expression. The obvious changes of microstructure of the ONH also were found according to the images of TEM. It can be concluded that the activated astrocytes might squeeze the optic nerve, likely leading to optic nerve distortion and axonal flow blockage.
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Affiliation(s)
- FAN PENG
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIPING MA
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIU LIU
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - LIN LI
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
| | - XIUQING QIAN
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing 100069, P. R. China
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16
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Lakshmanan Y, Wong FSY, Yu WY, Li SZC, Choi KY, So KF, Chan HHL. Lycium Barbarum Polysaccharides Rescue Neurodegeneration in an Acute Ocular Hypertension Rat Model Under Pre- and Posttreatment Conditions. Invest Ophthalmol Vis Sci 2019; 60:2023-2033. [PMID: 31067322 DOI: 10.1167/iovs.19-26752] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the posttreatment neuronal rescue effects of Lycium barbarum polysaccharides (LBP) in an acute ocular hypertensive (AOH) model. Methods Intraocular pressure (IOP) was elevated manometrically to 80 mm Hg (AOH) or 15 mm Hg (sham) for 120 minutes in adult Sprague-Dawley rats. Five experimental groups were considered: Three AOH groups were pretreated with PBS (vehicle) (n = 9), LBP 1 mg/kg (n = 8), or 10 mg/kg (n = 13), and one AOH group was posttreated with LBP 10 mg/kg (n = 8), once daily. The sham cannulation group (n = 5) received no treatment. Pretreatments commenced 7 days before and posttreatment 6 hours after AOH, and continued up through postcannulation day 28. All the animals underwent optical coherence tomography and electroretinogram measurements at baseline and postcannulation days 10 and 28. The ganglion cell layer (GCL) densities were quantified at day 28. Results Both inner retinal layer thickness (IRLT) and positive scotopic threshold response (pSTR) underwent significant reduction (≥50% of thickness and amplitude) in the vehicle group (P < 0.05). Pretreatment with LBP 1 and 10 mg/kg retained 77 ± 11% and 89 ± 8% of baseline IRLT, respectively, and preserved pSTR functions. The posttreatment group showed a significant reduction in IRLT (-35 ± 8%, P < 0.001) and pSTR (∼48% of baseline, P < 0.001) on day 10. By day 28, there was an improvement in functional pSTR (∼72% of baseline, P > 0.05) with no significant further thinning (-40 ± 8%, P = 0.15) relative to day 10. GCL density was reduced in vehicle control (P = 0.0001), but did not differ between sham and pre- and posttreated AOH groups. Conclusions The rescue effect of LBP posttreatment was observed later, which arrested the secondary degeneration and improved the retinal function.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Francisca Siu-Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Wing-Yan Yu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Serena Zhe-Chuang Li
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Kai-Yip Choi
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Kwok-Fai So
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
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17
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Mutlu U, Colijn JM, Ikram MA, Bonnemaijer PWM, Licher S, Wolters FJ, Tiemeier H, Koudstaal PJ, Klaver CCW, Ikram MK. Association of Retinal Neurodegeneration on Optical Coherence Tomography With Dementia: A Population-Based Study. JAMA Neurol 2019; 75:1256-1263. [PMID: 29946702 DOI: 10.1001/jamaneurol.2018.1563] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Importance Retinal structures may serve as a biomarker for dementia, but longitudinal studies examining this link are lacking. Objective To investigate the association of inner retinal layer thickness with prevalent and incident dementia in a general population of Dutch adults. Design, Setting, and Participants From September 2007 to June 2012, participants from the prospective population-based Rotterdam Study who were 45 years and older and had gradable retinal optical coherence tomography images and at baseline were free from stroke, Parkinson disease, multiple sclerosis, glaucoma, macular degeneration, retinopathy, myopia, hyperopia, and optic disc pathology were included. They were followed up until January 1, 2015, for the onset of dementia. Exposures Inner retinal layer thicknesses (ie, retinal nerve fiber layer [RNFL]) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses measured on optical coherence tomography images. Main Outcomes and Measures Odds ratios and hazard ratios for incident dementia per SD decrease in retinal layer thickness adjusted for age, sex, education, and cardiovascular risk factors. Results Of 5065 individuals eligible for optical coherence tomography scanning, 3289 (64.9%) (mean [SD] age 68.9 [9.9] years, 1879 [57%] women) were included in the analysis. Of these 3289 individuals, 41 (1.2%) already had dementia. Thinner GC-IPL was associated with prevalent dementia (odds ratio per SD decrease in GC-IPL, 1.37 [95% CI, 0.99-1.90]). No association was found of RNFL with prevalent dementia. During 14 674 person-years of follow-up (mean [SD], 4.5 [1.6] years), 86 individuals (2.6%) developed dementia of whom 68 (2.1%) had Alzheimer disease. Thinner RNFL at baseline was associated with an increased risk of developing dementia (hazard ratio per SD decrease in RNFL, 1.44 [95% CI, 1.19-1.75]), which was similar for Alzheimer disease (hazard ratio, 1.43 [95% CI, 1.15-1.78]). No association was found between GC-IPL thickness and incident dementia (hazard ratio, 1.13 [95% CI, 0.90-1.43]). Conclusions and Relevance Thinner RNFL is associated with an increased risk of dementia, including Alzheimer disease, suggesting that retinal neurodegeneration may serve as a preclinical biomarker for dementia.
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Affiliation(s)
- Unal Mutlu
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Johanna M Colijn
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Neurology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Pieter W M Bonnemaijer
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Silvan Licher
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Frank J Wolters
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Henning Tiemeier
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Psychiatry, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Peter J Koudstaal
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Neurology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Caroline C W Klaver
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Ophthalmology, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - M Kamran Ikram
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Neurology, Erasmus Medical Center, Rotterdam, the Netherlands
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18
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Pi S, Hormel TT, Wei X, Cepurna W, Camino A, Guo Y, Huang D, Morrison J, Jia Y. Monitoring retinal responses to acute intraocular pressure elevation in rats with visible light optical coherence tomography. NEUROPHOTONICS 2019; 6:041104. [PMID: 31312671 PMCID: PMC6624745 DOI: 10.1117/1.nph.6.4.041104] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/21/2019] [Indexed: 05/08/2023]
Abstract
Elevated intraocular pressure (IOP) is an important risk factor for glaucoma. However, the role of IOP in glaucoma progression, as well as retinal physiology in general, remains incompletely understood. We demonstrate the use of visible light optical coherence tomography to measure retinal responses to acute IOP elevation in Brown Norway rats. We monitored retinal responses in reflectivity, angiography, blood flow, oxygen saturation ( sO 2 ), and oxygen metabolism over a range of IOP from 10 to 100 mmHg. As IOP was elevated, nerve fiber layer reflectivity was found to decrease. Vascular perfusion in the three retinal capillary plexuses remained steady until IOP exceeded 70 mmHg and arterial flow was noted to reverse periodically at high IOPs. However, a significant drop in total retinal blood flow was observed first at 40 mmHg. As IOP increased, the venous sO 2 demonstrated a gradual decrease despite steady arterial sO 2 , which is consistent with increased arterial-venous oxygen extraction across the retinal capillary beds. Calculated total retinal oxygen metabolism was steady, reflecting balanced responses of blood flow and oxygen extraction, until IOP exceeded 40 mmHg, and fell to 0 at 70 and 80 mmHg. Above this, measurements were unattainable. All measurements reverted to baseline when the IOP was returned to 10 mmHg, indicating good recovery following acute pressure challenge. These results demonstrate the ability of this system to monitor retinal oxygen metabolism noninvasively and how it can help us understand retinal responses to elevated IOP.
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Affiliation(s)
- Shaohua Pi
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Tristan T. Hormel
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Xiang Wei
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - William Cepurna
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Acner Camino
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Yukun Guo
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - David Huang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - John Morrison
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Yali Jia
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
- Address all correspondence to Yali Jia, E-mail:
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19
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Relationship between preoperative high intraocular pressure and retinal nerve fibre layer thinning after glaucoma surgery. Sci Rep 2019; 9:13901. [PMID: 31554879 PMCID: PMC6761197 DOI: 10.1038/s41598-019-50406-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 09/11/2019] [Indexed: 12/13/2022] Open
Abstract
Recent reports show varying results regarding peripapillary retinal nerve fibre layer (RNFL) thickness after intraocular pressure (IOP)-lowering glaucoma surgery. We hypothesised that different levels of the preoperative IOP influence RNFL thickness. A total of 60 patients (60 eyes) with glaucoma, who underwent glaucoma surgery and had a stable postoperative mean IOP < 22 mmHg, were enrolled. The RNFL thickness was measured using spectral domain optical coherence tomography, before and at 3–6 months after surgery. The preoperative peak IOP, 37.4 ± 10.8 mmHg, decreased to a postoperative mean IOP of 14.8 ± 3.5 mmHg (p < 0.001). The average RNFL thickness was significantly reduced from 75.6 ± 17.7 μm to 70.2 ± 15.8 μm (p < 0.001). In subgroup analyses, only patients with a preoperative peak IOP ≥ median value (37 mmHg) exhibited significant RNFL thinning (9.7 ± 6.6 μm, p < 0.001) associated with a higher preoperative peak IOP (r = 0.475, p = 0.008). The RNFL thinning was evident for a few months after glaucoma surgery in patients with a higher preoperative peak IOP, although the postoperative IOP was stable.
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Bhandari A, Smith JC, Zhang Y, Jensen AA, Reid L, Goeser T, Fan S, Ghate D, Van Hook MJ. Early-Stage Ocular Hypertension Alters Retinal Ganglion Cell Synaptic Transmission in the Visual Thalamus. Front Cell Neurosci 2019; 13:426. [PMID: 31607867 PMCID: PMC6761307 DOI: 10.3389/fncel.2019.00426] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/04/2019] [Indexed: 12/21/2022] Open
Abstract
Axonopathy is a hallmark of many neurodegenerative diseases including glaucoma, where elevated intraocular pressure (ocular hypertension, OHT) stresses retinal ganglion cell (RGC) axons as they exit the eye and form the optic nerve. OHT causes early changes in the optic nerve such as axon atrophy, transport inhibition, and gliosis. Importantly, many of these changes appear to occur prior to irreversible neuronal loss, making them promising points for early diagnosis of glaucoma. It is unknown whether OHT has similarly early effects on the function of RGC output to the brain. To test this possibility, we elevated eye pressure in mice by anterior chamber injection of polystyrene microbeads. Five weeks post-injection, bead-injected eyes showed a modest RGC loss in the peripheral retina, as evidenced by RBPMS antibody staining. Additionally, we observed reduced dendritic complexity and lower spontaneous spike rate of On-αRGCs, targeted for patch clamp recording and dye filling using a Opn4-Cre reporter mouse line. To determine the influence of OHT on retinal projections to the brain, we expressed Channelrhodopsin-2 (ChR2) in melanopsin-expressing RGCs by crossing the Opn4-Cre mouse line with a ChR2-reporter mouse line and recorded post-synaptic responses in thalamocortical relay neurons in the dorsal lateral geniculate nucleus (dLGN) of the thalamus evoked by stimulation with 460 nm light. The use of a Opn4-Cre reporter system allowed for expression of ChR2 in a narrow subset of RGCs responsible for image-forming vision in mice. Five weeks following OHT induction, paired pulse and high-frequency stimulus train experiments revealed that presynaptic vesicle release probability at retinogeniculate synapses was elevated. Additionally, miniature synaptic current frequency was slightly reduced in brain slices from OHT mice and proximal dendrites of post-synaptic dLGN relay neurons, assessed using a Sholl analysis, showed a reduced complexity. Strikingly, these changes occurred prior to major loss of RGCs labeled with the Opn4-Cre mouse, as indicated by immunofluorescence staining of ChR2-expressing retinal neurons. Thus, OHT leads to pre- and post-synaptic functional and structural changes at retinogeniculate synapses. Along with RGC dendritic remodeling and optic nerve transport changes, these retinogeniculate synaptic changes are among the earliest signs of glaucoma.
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Affiliation(s)
- Ashish Bhandari
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jennie C Smith
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Yang Zhang
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Creighton University School of Medicine, Omaha, NE, United States.,Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Aaron A Jensen
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Lisa Reid
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Toni Goeser
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Shan Fan
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Deepta Ghate
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Matthew J Van Hook
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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Huang XR, Knighton RW, Spector YZ, Kong W, Qiao J. Temporal change of retinal nerve fiber layer reflectance speckle in normal and hypertensive retinas. Exp Eye Res 2019; 186:107738. [PMID: 31325451 PMCID: PMC6703932 DOI: 10.1016/j.exer.2019.107738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 06/20/2019] [Accepted: 07/16/2019] [Indexed: 11/29/2022]
Abstract
This study investigated temporal change of retinal nerve fiber layer (RNFL) reflectance speckle in retinas with ocular hypertensive (OHT) damage and in control retinas from untreated eyes. Experimental OHT damage to rat retinas was induced by laser photocoagulation of the trabecular meshwork. A series of 660 nm reflectance images was collected from isolated retinas at 10-sec intervals. Areas containing speckled texture were selected on nerve fiber bundles. Correlation coefficients between images with different imaging delays were calculated and plotted as a function of delay. To evaluate the temporal change of speckles, decay of correlation coefficients with time was fitted with an exponential function characterized by a time constant τ. Reflectance per unit thickness (σ) of the areas was also measured and low σ was used as a surrogate of OHT damage. Speckle phenomena occurred in the control RNFL and the RNFL with reduced σ. In the control retinas, τ and σ were nearly constant along bundles but differed significantly among bundles in the same retinas. Among the control retinas, σ was similar, whereas τ varied significantly. In the retinas with OHT damage (low σ) τ could be within, greater or lower than the range in controls. The parameters τ and σ provide independent assessment of the RNFL with OHT damage. Measurements of temporal change of RNFL reflectance speckle may offer a method for detecting functional abnormality of the RNFL.
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Affiliation(s)
- Xiang-Run Huang
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, FL, USA.
| | - Robert W Knighton
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Ye Z Spector
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Wei Kong
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Jianzhong Qiao
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, FL, USA
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22
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Ledolter J, Kardon RH. Assessing Trends in Functional and Structural Characteristics: A Survey of Statistical Methods With an Example From Ophthalmology. Transl Vis Sci Technol 2018; 7:34. [PMID: 30402341 PMCID: PMC6213778 DOI: 10.1167/tvst.7.5.34] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 09/08/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose Clinical decisions on treatment are usually based on short-term records of consecutive measurements of structure and function. Useful models for analyzing average trends and a description of statistical methods for classifying individual subjects on the basis of subject-specific trend progressions are presented. Methods Random effects trend models allow intercepts and slopes of the trend regression to vary across subjects around group-specific mean intercepts and mean slopes. Model results assess whether average intercepts and slopes and subject variability in intercepts and slopes are the same across groups. Fisher's discriminant functions are used for classification. Results Methods are presented and illustrated on structural visual data from a multiyear perimetry study. Average thickness of the ganglion cell layer from the optical coherence tomography macula scan and of the retinal nerve fiber layer from the optic disc scan for both glaucoma patients on optimal treatment and normal subjects are analyzed. The random effects trend model shows that average intercepts of glaucoma patients and normal subjects are quite different, but that average slopes are the same, and that the subject variability in both intercepts and slopes is larger for the glaucoma group. These findings explain why the subject-specific trend progression is not a good classifier; it is the level of the measurement (intercept or baseline value) that carries useful information in this particular cohort example. Translational Relevance Clinicians base decisions on short-term records of consecutive measurements and need simple statistical tools to analyze the information. This paper discusses useful methods for analyzing short time series data. Model results assess whether there exist significant trends and whether average trends are different across groups. The paper discusses whether clinical measures classify patients reliably into disease groups, given their variability. With ever more available data, classification plays a central role of personalized medicine.
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Affiliation(s)
- Johannes Ledolter
- Department of Management Sciences at the University of Iowa, Iowa City, IA, USA.,Iowa City VA Medical Center, Iowa City, IA, USA
| | - Randy H Kardon
- Iowa City VA Medical Center, Iowa City, IA, USA.,Department of Ophthalmology and Visual Sciences at the University of Iowa Hospital, Iowa City, IA, USA
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23
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Yao F, Zhang E, Gao Z, Ji H, Marmouri M, Xia X. Did you choose appropriate tracer for retrograde tracing of retinal ganglion cells? The differences between cholera toxin subunit B and Fluorogold. PLoS One 2018; 13:e0205133. [PMID: 30289890 PMCID: PMC6173421 DOI: 10.1371/journal.pone.0205133] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/19/2018] [Indexed: 12/31/2022] Open
Abstract
Cholera toxin subunit B (CTB) and Fluorogold(FG) are two widely utilized retrograde tracers to assess the number and function of retinal ganglion cells (RGCs). However, the relative advantages and disadvantages of these tracers remain unclear, which may lead to their inappropriate application. In this study, we compared these tracers by separately injecting the tracer into the superior Colliculi (SC) in rats, one or 2 weeks later, the rats were sacrificed, and their retinas, brains, and optic nerves were collected. From the first to second week, FG displayed a greater number of labeled RGCs and a larger diffusion area in the SC than CTB; The number of CTB labeled RGCs and the diffusion area of CTB in the SC increased significantly, but there was no distinction between FG; Furthermore, CTB exhibited more labeled RGC neurites and longer neurites than FG, but no difference was evident between the same trace; The optic nerves labeled using CTB were much clearer than those labeled using FG. In conclusion, both CTB and FG can be used for the retrograde labeling of RGCs in rats at 1 or 2 weeks. FG achieves retrograde labeling of a greater number of RGCs than CTB, whereas CTB better delineates the morphology of RGCs. Furthermore, CTB seems more suitable for retrograde labeling of some small, non-image forming nuclei in the brain to which certain RGC subtypes project their axons.
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Affiliation(s)
- Fei Yao
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Endong Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhaolin Gao
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hongpei Ji
- Department of Ophthalmology, The People’s Hospital of Guizhou Province, Guiyang, Guizhou, China
| | - Mahmoud Marmouri
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- * E-mail:
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24
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Zhang Y, Bao Y, Qiu W, Peng L, Fang L, Xu Y, Yang H. Structural and visual functional deficits in a rat model of neuromyelitis optica spectrum disorders related optic neuritis. Exp Eye Res 2018; 175:124-132. [DOI: 10.1016/j.exer.2018.06.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/30/2018] [Accepted: 06/13/2018] [Indexed: 12/15/2022]
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25
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Fry LE, Fahy E, Chrysostomou V, Hui F, Tang J, van Wijngaarden P, Petrou S, Crowston JG. The coma in glaucoma: Retinal ganglion cell dysfunction and recovery. Prog Retin Eye Res 2018; 65:77-92. [DOI: 10.1016/j.preteyeres.2018.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/18/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
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26
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Jonas JB, Aung T, Bourne RR, Bron AM, Ritch R, Panda-Jonas S. Glaucoma. Lancet 2017; 390:2183-2193. [PMID: 28577860 DOI: 10.1016/s0140-6736(17)31469-1] [Citation(s) in RCA: 795] [Impact Index Per Article: 113.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 04/11/2017] [Accepted: 04/26/2017] [Indexed: 12/28/2022]
Abstract
Glaucoma is a heterogeneous group of diseases characterised by cupping of the optic nerve head and visual-field damage. It is the most frequent cause of irreversible blindness worldwide. Progression usually stops if the intraocular pressure is lowered by 30-50% from baseline. Its worldwide age-standardised prevalence in the population aged 40 years or older is about 3·5%. Chronic forms of glaucoma are painless and symptomatic visual-field defects occur late. Early detection by ophthalmological examination is mandatory. Risk factors for primary open-angle glaucoma-the most common form of glaucoma-include older age, elevated intraocular pressure, sub-Saharan African ethnic origin, positive family history, and high myopia. Older age, hyperopia, and east Asian ethnic origin are the main risk factors for primary angle-closure glaucoma. Glaucoma is diagnosed using ophthalmoscopy, tonometry, and perimetry. Treatment to lower intraocular pressure is based on topical drugs, laser therapy, and surgical intervention if other therapeutic modalities fail to prevent progression.
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Affiliation(s)
- Jost B Jonas
- Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.
| | - Tin Aung
- Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Rupert R Bourne
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, UK
| | - Alain M Bron
- Department of Ophthalmology, University Hospital, Dijon, France; Eye and Nutrition Research Group, Bourgogne Franche-Comté University, Dijon, France
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
| | - Songhomitra Panda-Jonas
- Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany
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27
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Ocular fundus pulsations within the posterior rat eye: Chorioscleral motion and response to elevated intraocular pressure. Sci Rep 2017; 7:8780. [PMID: 28821834 PMCID: PMC5562765 DOI: 10.1038/s41598-017-09310-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022] Open
Abstract
A multi-functional optical coherence tomography (OCT) approach is presented to determine ocular fundus pulsations as an axial displacement between the retina and the chorioscleral complex in the albino rat eye. By combining optical coherence elastography and OCT angiography (OCTA), we measure subtle deformations in the nanometer range within the eye and simultaneously map retinal and choroidal perfusion. The conventional OCT reflectivity contrast serves as a backbone to segment the retina and to define several slabs which are subsequently used for quantitative ocular pulsation measurements as well as for a qualitative exploration of the multi-functional OCT image data. The proposed concept is applied in healthy albino rats as well as in rats under acute elevation of the intraocular pressure (IOP). The evaluation of this experiment revealed an increased pulsatility and deformation between the retinal and chorioscleral complex while increasing the IOP level from 15 mmHg to 65 mmHg. At IOP levels exceeding 65 mmHg, the pulsatility decreased significantly and retinal as well as choroidal perfusion vanished in OCTA. Furthermore, the evaluation of the multi-parametric experiment revealed a spatial correlation between fundus pulsatility and choroidal blood flow. This indicates that the assessed pulsatility may be a valuable parameter describing the choroidal perfusion.
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28
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Morrison JC, Cepurna WO, Tehrani S, Choe TE, Jayaram H, Lozano DC, Fortune B, Johnson EC. A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma. Invest Ophthalmol Vis Sci 2017; 57:6700-6711. [PMID: 27942722 PMCID: PMC5156512 DOI: 10.1167/iovs.16-20573] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats. Methods The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography (ERG). Results During CEI, mean arterial pressure (99 ± 6 mm Hg) and other physiologic parameters remained stable. An 8-hour CEI at 60 mm Hg produced significant focal axonal degeneration 10 days after exposure, with superior lesions in 83% of ON. Message analysis in CEI ONH demonstrated expression responses previously identified in minimally injured ONH following chronic IOP elevation, as well as their sequential patterns. Anesthesia with cannulation at 20 mm Hg did not alter these message levels. Electroretinographic A- and B-waves, following a significant reduction at 2 days after CEI, were fully recovered at 2 weeks, while peak scotopic threshold response (pSTR) remained mildly but significantly depressed. Conclusions A single CEI reproduces ONH message changes and patterns of ON injury previously observed with chronic IOP elevation. Controlled elevation of IOP can allow detailed determination of ONH cellular and functional responses to an injurious IOP insult and provide a platform for developing future therapeutic interventions.
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Affiliation(s)
- John C Morrison
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - William O Cepurna
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Shandiz Tehrani
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Hari Jayaram
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States 2Glaucoma Service, NIHR Moorfields Biomedical Research Centre, London, United Kingdom
| | - Diana C Lozano
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Portland, Oregon, United States
| | - Elaine C Johnson
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
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29
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Lu W, Albalawi F, Beckel JM, Lim JC, Laties AM, Mitchell CH. The P2X7 receptor links mechanical strain to cytokine IL-6 up-regulation and release in neurons and astrocytes. J Neurochem 2017; 141:436-448. [PMID: 28244110 DOI: 10.1111/jnc.13998] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/11/2017] [Accepted: 02/09/2017] [Indexed: 12/15/2022]
Abstract
Mechanical strain in neural tissues can lead to the up-regulation and release of multiple cytokines including interleukin 6 (IL-6). In the retina, the mechanosensitive release of ATP can autostimulate P2X7 receptors on both retinal ganglion cell neurons and optic nerve head astrocytes. Here, we asked whether the purinergic signaling contributed to the IL-6 response to increased intraocular pressure (IOP) in vivo, and stretch or swelling in vitro. Rat and mouse eyes were exposed to non-ischemic elevations in IOP to 50-60 mmHg for 4 h. A PCR array was used to screen cytokine changes, with quantitative (q)PCR used to confirm mRNA elevations and immunoblots used for protein levels. P2X7 antagonist Brilliant Blue G (BBG) and agonist (4-benzoyl-benzoyl)-ATP (BzATP) were injected intravitreally. ELISA was used to quantify IL-6 release from optic nerve head astrocytes or retinal ganglion cells. Receptor identity was confirmed pharmacologically and in P2X7-/- mice, acute elevation of IOP altered retinal expression of multiple cytokine genes. Elevation of IL-6 was greatest, with expression of IL1rn, IL24, Tnf, Csf1, and Lif also increased more than twofold, while expression of Tnfsf11, Gdf9, and Tnfsf4 were reduced. qPCR confirmed the rise in IL-6 and extracellular ATP marker ENTPD1, but not pro-apoptotic genes. Intravitreal injection of P2X7 receptor antagonist BBG prevented the pressure-dependent rise in IL-6 mRNA and protein in the rat retina, while injection of P2X7 receptor agonist BzATP was sufficient to elevate IL-6 expression. IOP elevation increased IL-6 in wild-type but not P2X7R knockout mice. Application of mechanical strain to isolated optic nerve head astrocytes increased IL-6 levels. This response was mimicked by agonist BzATP, but blocked by antagonists BBG and A839977. Stretch or BzATP led to IL-6 release from both astrocytes and isolated retinal ganglion cells. The mechanosensitive up-regulation and release of cytokine IL-6 from the retina involves the P2X7 receptor, with both astrocytes and neurons contributing to the response.
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Affiliation(s)
- Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Farraj Albalawi
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthodontics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pennsylvania, USA
| | - Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alan M Laties
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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30
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Vidal-Sanz M, Galindo-Romero C, Valiente-Soriano FJ, Nadal-Nicolás FM, Ortin-Martinez A, Rovere G, Salinas-Navarro M, Lucas-Ruiz F, Sanchez-Migallon MC, Sobrado-Calvo P, Aviles-Trigueros M, Villegas-Pérez MP, Agudo-Barriuso M. Shared and Differential Retinal Responses against Optic Nerve Injury and Ocular Hypertension. Front Neurosci 2017; 11:235. [PMID: 28491019 PMCID: PMC5405145 DOI: 10.3389/fnins.2017.00235] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/07/2017] [Indexed: 12/05/2022] Open
Abstract
Glaucoma, one of the leading causes of blindness worldwide, affects primarily retinal ganglion cells (RGCs) and their axons. The pathophysiology of glaucoma is not fully understood, but it is currently believed that damage to RGC axons at the optic nerve head plays a major role. Rodent models to study glaucoma include those that mimic either ocular hypertension or optic nerve injury. Here we review the anatomical loss of the general population of RGCs (that express Brn3a; Brn3a+RGCs) and of the intrinsically photosensitive RGCs (that express melanopsin; m+RGCs) after chronic (LP-OHT) or acute (A-OHT) ocular hypertension and after complete intraorbital optic nerve transection (ONT) or crush (ONC). Our studies show that all of these insults trigger RGC death. Compared to Brn3a+RGCs, m+RGCs are more resilient to ONT, ONC, and A-OHT but not to LP-OHT. There are differences in the course of RGC loss both between these RGC types and among injuries. An important difference between the damage caused by ocular hypertension or optic nerve injury appears in the outer retina. Both axotomy and LP-OHT induce selective loss of RGCs but LP-OHT also induces a protracted loss of cone photoreceptors. This review outlines our current understanding of the anatomical changes occurring in rodent models of glaucoma and discusses the advantages of each one and their translational value.
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Affiliation(s)
- Manuel Vidal-Sanz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Caridad Galindo-Romero
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Francisco J Valiente-Soriano
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Francisco M Nadal-Nicolás
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Arturo Ortin-Martinez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Giuseppe Rovere
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Manuel Salinas-Navarro
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Fernando Lucas-Ruiz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Maria C Sanchez-Migallon
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Paloma Sobrado-Calvo
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Marcelino Aviles-Trigueros
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - María P Villegas-Pérez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - Marta Agudo-Barriuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
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Wang J, Valiente-Soriano FJ, Nadal-Nicolás FM, Rovere G, Chen S, Huang W, Agudo-Barriuso M, Jonas JB, Vidal-Sanz M, Zhang X. MicroRNA regulation in an animal model of acute ocular hypertension. Acta Ophthalmol 2017; 95:e10-e21. [PMID: 27535721 PMCID: PMC6213559 DOI: 10.1111/aos.13227] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/10/2016] [Indexed: 12/12/2022]
Abstract
Purpose To analyse miRNA regulation in a rat model of acute ocular hypertension (AOH). Methods Acute ocular hypertension (AOH) was induced in the left eye of adult albino rats by inserting a cannula connected with a saline container into the anterior chamber. The contralateral eye served as a control. Seven days later, animals were killed. Retinas were used either for quantitative analysis of retinal ganglion cells (RGCs) and microglial cells or for miRNA array hybridization, qRT‐PCR and Western blotting. Results Anatomically, AOH caused axonal degeneration, a significant loss of RGCs and a significant increase in microglial cells in the ganglion cell layer. The miRNAs microarray analysis revealed 31 differentially expressed miRNAs in the AOH versus control group, and the regulation of 12 selected microRNAs was further confirmed by qRT‐PCR. Bioinformatic analysis indicates that several signalling pathways are putatively regulated by the validated miRNAs. Of particular interest was the inflammatory pathway signalled by mitogen‐activated protein kinases (MAPKs). In agreement with the in silico analysis, p38 MAP kinase, tumour necrosis factor‐alpha (TNF‐α) and iNOS proteins were significantly upregulated in the AOH retinas. Conclusions Acute IOP elevation led to changes in the expression of miRNAs, whose target genes were associated with the regulation of microglia‐mediated neuroinflammation or neural apoptosis. Addressing miRNAs in the process of retinal ischaemia and optic nerve damage in association with high IOP elevation may open new avenues in preventing retinal ganglion cell apoptosis and may serve as target for future therapeutic regimen in acute ocular hypertension and retinal ischaemic conditions.
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Affiliation(s)
- Jiawei Wang
- Zhongshan Ophthalmic Center; State Key Laboratory of Ophthalmology; Sun Yat-Sen University; Guangzhou China
- Eye Center of Shandong University; The Second Hospital of Shandong University; Jinan China
| | - Francisco J. Valiente-Soriano
- Department of Ophthalmology; University of Murcia and Murcian Institute of Biosanitary Research-Hospital Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Francisco M. Nadal-Nicolás
- Department of Ophthalmology; University of Murcia and Murcian Institute of Biosanitary Research-Hospital Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Giuseppe Rovere
- Department of Ophthalmology; University of Murcia and Murcian Institute of Biosanitary Research-Hospital Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Shida Chen
- Zhongshan Ophthalmic Center; State Key Laboratory of Ophthalmology; Sun Yat-Sen University; Guangzhou China
| | - Wenbin Huang
- Zhongshan Ophthalmic Center; State Key Laboratory of Ophthalmology; Sun Yat-Sen University; Guangzhou China
| | - Marta Agudo-Barriuso
- Department of Ophthalmology; University of Murcia and Murcian Institute of Biosanitary Research-Hospital Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Jost B. Jonas
- Department of Ophthalmology; Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
| | - Manuel Vidal-Sanz
- Department of Ophthalmology; University of Murcia and Murcian Institute of Biosanitary Research-Hospital Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Xiulan Zhang
- Zhongshan Ophthalmic Center; State Key Laboratory of Ophthalmology; Sun Yat-Sen University; Guangzhou China
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Smith CA, Vianna JR, Chauhan BC. Assessing retinal ganglion cell damage. Eye (Lond) 2017; 31:209-217. [PMID: 28085141 PMCID: PMC5306472 DOI: 10.1038/eye.2016.295] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 11/09/2022] Open
Abstract
Retinal ganglion cell (RGC) loss is the hallmark of optic neuropathies, including glaucoma, where damage to RGC axons occurs at the level of the optic nerve head. In experimental glaucoma, damage is assessed at the axon level (in the retinal nerve fibre layer and optic nerve head) or at the soma level (in the retina). In clinical glaucoma where measurements are generally limited to non-invasive techniques, structural measurements of the retinal nerve fibre layer and optic nerve head, or functional measurements with perimetry provide surrogate estimates of RGC integrity. These surrogate measurements, while clinically useful, are several levels removed from estimating actual RGC loss. Advances in imaging, labelling techniques, and transgenic medicine are making enormous strides in experimental glaucoma, providing knowledge on the pathophysiology of glaucoma, its progression and testing new therapeutic avenues. Advances are also being made in functional imaging of RGCs. Future efforts will now be directed towards translating these advances to clinical care.
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Affiliation(s)
- C A Smith
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - J R Vianna
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - B C Chauhan
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
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Fialová S, Augustin M, Fischak C, Schmetterer L, Handschuh S, Glösmann M, Pircher M, Hitzenberger CK, Baumann B. Posterior rat eye during acute intraocular pressure elevation studied using polarization sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:298-314. [PMID: 28101419 PMCID: PMC5231300 DOI: 10.1364/boe.8.000298] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/01/2016] [Accepted: 12/12/2016] [Indexed: 05/05/2023]
Abstract
Polarization sensitive optical coherence tomography (PS-OCT) operating at 840 nm with axial resolution of 3.8 µm in tissue was used for investigating the posterior rat eye during an acute intraocular pressure (IOP) increase experiment. IOP was elevated in the eyes of anesthetized Sprague Dawley rats by cannulation of the anterior chamber. Three dimensional PS-OCT data sets were acquired at IOP levels between 14 mmHg and 105 mmHg. Maps of scleral birefringence, retinal nerve fiber layer (RNFL) retardation and relative RNFL/retina reflectivity were generated in the peripapillary area and quantitatively analyzed. All investigated parameters showed a substantial correlation with IOP. In the low IOP range of 14-45 mmHg only scleral birefringence showed statistically significant correlation. The polarization changes observed in the PS-OCT imaging study presented in this work suggest that birefringence of the sclera may be a promising IOP-related parameter to investigate.
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Affiliation(s)
- Stanislava Fialová
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Corinna Fischak
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Department of Clinical Pharmacology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Leopold Schmetterer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Department of Clinical Pharmacology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower Level 6, 169856 Singapore, Republic of Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Novena Campus, 11 Mandalay Road, 308232 Singapore, Republic of Singapore
| | - Stephan Handschuh
- VetCore Facility for Research and Technology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Martin Glösmann
- VetCore Facility for Research and Technology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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Tehrani S, Davis L, Cepurna WO, Choe TE, Lozano DC, Monfared A, Cooper L, Cheng J, Johnson EC, Morrison JC. Astrocyte Structural and Molecular Response to Elevated Intraocular Pressure Occurs Rapidly and Precedes Axonal Tubulin Rearrangement within the Optic Nerve Head in a Rat Model. PLoS One 2016; 11:e0167364. [PMID: 27893827 PMCID: PMC5125687 DOI: 10.1371/journal.pone.0167364] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/12/2016] [Indexed: 02/01/2023] Open
Abstract
Glaucomatous axon injury occurs at the level of the optic nerve head (ONH) in response to uncontrolled intraocular pressure (IOP). The temporal response of ONH astrocytes (glial cells responsible for axonal support) to elevated IOP remains unknown. Here, we evaluate the response of actin-based astrocyte extensions and integrin-based signaling within the ONH to 8 hours of IOP elevation in a rat model. IOP elevation of 60 mm Hg was achieved under isoflurane anesthesia using anterior chamber cannulation connected to a saline reservoir. ONH astrocytic extension orientation was significantly and regionally rearranged immediately after IOP elevation (inferior ONH, 43.2° ± 13.3° with respect to the anterior-posterior axis versus 84.1° ± 1.3° in controls, p<0.05), and re-orientated back to baseline orientation 1 day post IOP normalization. ONH axonal microtubule filament label intensity was significantly reduced 1 and 3 days post IOP normalization, and returned to control levels on day 5. Phosphorylated focal adhesion kinase (FAK) levels steadily decreased after IOP normalization, while levels of phosphorylated paxillin (a downstream target of FAK involved in focal adhesion dynamics) were significantly elevated 5 days post IOP normalization. The levels of phosphorylated cortactin (a downstream target of Src kinase involved in actin polymerization) were significantly elevated 1 and 3 days post IOP normalization and returned to control levels by day 5. No significant axon degeneration was noted by morphologic assessment up to 5 days post IOP normalization. Actin-based astrocyte structure and signaling within the ONH are significantly altered within hours after IOP elevation and prior to axonal cytoskeletal rearrangement, producing some responses that recover rapidly and others that persist for days despite IOP normalization.
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Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Lauren Davis
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - William O. Cepurna
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Tiffany E. Choe
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Diana C. Lozano
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Ashley Monfared
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Lauren Cooper
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Joshua Cheng
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Elaine C. Johnson
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - John C. Morrison
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
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Liu H, He Z, Nguyen CTO, Vingrys AJ, Bui BV. Reversal of functional loss in a rat model of chronic intraocular pressure elevation. Ophthalmic Physiol Opt 2016; 37:71-81. [DOI: 10.1111/opo.12331] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/17/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Hsin‐Hua Liu
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | - Zheng He
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | | | - Algis J. Vingrys
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | - Bang V. Bui
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
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DAI PEISHAN, HAN HAN, ZHAO YALI, FAN MIN. FINITE ELEMENT ANALYSIS OF THE MECHANICAL CHARACTERISTICS OF GLAUCOMA. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose: Construct a finite element model of the human eye to quantitatively analyze the mechanical characteristics of the human eye, especially the glaucoma damage process of the optic nerve head (ONH). Method: First, the geometry model of the human eye with nonuniform thickness was established based on a reasonable hypothesis and assumptions. Because the ONH is an important factor for glaucoma, we refine the structure of the ONH with lamina cribrosa. Then, mesh division was applied for finite element analysis. To simplify the complexity of the analysis, the materials of the model were assumed to be isotropic linear elastic materials, and physical properties such as Young’s modulus and Poisson’s ratio were set according to published literature. Next, proper constraints and loads were applied to the model and solved with a finite element method. Result: A finite element model of the human eye was created to simulate the mechanical characteristics of the eye structures under high intraocular pressure (IOP). The ONH depressed 1.057[Formula: see text]mm under 0.009[Formula: see text]MPa pressure to simulate high IOP. Conclusion: The constructed model is able to quantitatively simulate excavation of the optic disc and damage of the optic nerve. The result proved Houcheng Liang’s hypothesis about the ONH damage mechanism in glaucoma.
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Affiliation(s)
- PEISHAN DAI
- Department of Biomedical Engineering, School of Geosciences and Info-Physics, Central South University, Changsha 410083, P. R. China
| | - HAN HAN
- Department of Electrical and Computer Engineering, National University of Singapore, S117576, Singapore
| | - YALI ZHAO
- Department of Biomedical Engineering, School of Geosciences and Info-Physics, Central South University, Changsha 410083, P. R. China
| | - MIN FAN
- Department of Education and Law, Hunan Women’s University, Changsha 410004, P. R. China
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Zhang Z, Wu S, Jonas JB, Zhang J, Liu K, Lu Q, Wang N. Dynein, kinesin and morphological changes in optic nerve axons in a rat model with cerebrospinal fluid pressure reduction: the Beijing Intracranial and Intraocular Pressure (iCOP) study. Acta Ophthalmol 2016; 94:266-75. [PMID: 26178710 DOI: 10.1111/aos.12768] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/21/2015] [Accepted: 04/19/2015] [Indexed: 12/11/2022]
Abstract
PURPOSE To examine the influence of experimentally reduced cerebrospinal fluid pressure (CSFP) as compared to elevated intraocular pressure (IOP) on axonal morphology and axonal motor proteins in retinal ganglion cells (RGCs). METHODS The experimental study included 39 rats which underwent cerebrospinal fluid drainage for 6 hr, 30 rats which unilaterally underwent IOP elevation for 6 hr and 30 rats in a control group. Six hours after baseline, the animals were killed and the eyes were histologically and immunohistochemically examined. RESULTS In experimental models in the high-IOP group and the low-CSFP group as compared to the control group, RGC axons became abnormally dilated and accumulated vesicles. Both groups as compared to the control group showed an accumulation of dynein IC (intermediate chain) at the optic nerve head and retina and a reduction in kinesin HC (heavy chain) immunoreactivity in the optic nerve fibre axons. As a corollary, Western blot analysis revealed an elevation of dynein IC protein levels in the optic nerve head and retina and a decrease in kinesin HC protein levels in the optic nerve. CONCLUSIONS Experimental models with an acute IOP rise or with an acute CSFP reduction showed similar morphologic changes in the retinal ganglion cell axons and similar immunohistochemical changes in the axonal motor proteins kinesin HC and dynein IC. It supports the hypothesis that an experimental model with an acute reduction in CSFP as well as an experimental model with an acute rise in IOP may share similarities in the process of optic nerve damage.
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Affiliation(s)
- Zheng Zhang
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
- Beijing Institute of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Shen Wu
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Jost B. Jonas
- Beijing Institute of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
- Department of Ophthalmology; Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg; Mannheim Germany
| | - Jingxue Zhang
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Kegao Liu
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Qingjun Lu
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
- Beijing Institute of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Ningli Wang
- Beijing Ophthalmology and Visual Sciences Key Laboratory; Beijing Tongren Eye Center; Beijing Tongren Hospital; Capital Medical University; Beijing China
- Beijing Institute of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
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Zhao HX, Liu H, Niu CM, Guan WY. Influence of transient intraocular pressure elevation during laser in situ keratomileusis on rabbit retina thickness. Int J Ophthalmol 2015; 8:1089-93. [PMID: 26682153 PMCID: PMC4651869 DOI: 10.3980/j.issn.2222-3959.2015.06.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 02/09/2015] [Indexed: 01/23/2023] Open
Abstract
AIM To utilize tissue micro measurement to study the effect of transient high intraocular pressure (IOP) induced by different durations of suction during laser in situ keratomileusis (LASIK) on rabbit retina thickness. METHODS Sixty healthy New Zealand white rabbits were randomly divided into a control group, and 3 negative-pressure suction groups (20s group, 45s group, and 3min group) and each group was comprised of 15 rabbits (30 eyes); the latter 3 groups were the transient high IOP models. The retinal tissue around the papilledema was separated. Hematoxylin and eosin (HE) staining was carried out to generate slices for light microscopy. The changes in the retina thickness values of each layer were measured for all animals in each group at different postoperative recovery periods and compared with the values recorded for the animals in the control group. The thickness of the retinal tissue showed a normal distribution. The ANOVA was performed by using SPSS13.0 statistic software. RESULTS In the comparison between the 20s and 45s negative-pressure suction groups and the control group, no significant differences were observed, except at 14d. Significant difference was observed between the 3min negative-pressure suction group and the control group, and the retina thickness value of each layer reached a peak at 14d after repair. CONCLUSION Conventional negative suction during LASIK may not lead to significant changes in retinal tissue thickness; however, if the suction duration is increased to 3min, it will cause significant changes in retinal tissue thickness.
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Affiliation(s)
- Hai-Xia Zhao
- Department of Ophthalmology, the Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China
| | - Hui Liu
- Department of Ophthalmology, the Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China
| | - Chun-Mei Niu
- Department of Ophthalmology, the Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China
| | - Wen-Ying Guan
- Department of Ophthalmology, the Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China
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Jiang SM, Zeng LP, Zeng JH, Tang L, Chen XM, Wei X. β-III-Tubulin: a reliable marker for retinal ganglion cell labeling in experimental models of glaucoma. Int J Ophthalmol 2015; 8:643-52. [PMID: 26309856 DOI: 10.3980/j.issn.2222-3959.2015.04.01] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/22/2015] [Indexed: 02/05/2023] Open
Abstract
AIM To evaluate the reliability of β-III-Tubulin protein as a retinal ganglion cell (RGC) marker in the experimental glaucoma model. METHODS Glaucoma mouse models were established by injecting polystyrene microbeads into the anterior chamber of C57BL/6J mice, then their retinas were obtained 14d and 28d after the intraocular pressure (IOP) was elevated. Retinal flat mounts and sections were double-labeled by fluorogold (FG) and β-III-Tubulin antibody or single-labeled by β-III-Tubulin antibody, then RGCs were counted and compared respectively. RESULTS IOP of the injected eyes were elevated significantly and reached the peak at 22.8±0.7 mm Hg by day 14 after injection, then dropped to 11.3±0.7 mm Hg by day 28. RGC numbers counted by FG labeling and β-III-Tubulin antibody labeling were 64 807±4930 and 64614±5054 respectively in the control group, with no significant difference. By day 14, RGCs in the experimental group decreased significantly compared to the control group, but there was no significant difference between the FG labeling counting and the β-III-Tubulin antibody labeling counting either in the experimental group or in the control group. The result was similar by day 28, with further RGC loss. CONCLUSION Our result suggested that the β-III-Tubulin protein was not affected by IOP elevation and can be used as a reliable marker for RGC in experimental models of glaucoma.
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Affiliation(s)
- Shan-Ming Jiang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Li-Ping Zeng
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ji-Hong Zeng
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Li Tang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xiao-Ming Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xin Wei
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
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Zhang J, Zhou YH. Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome. Int J Ophthalmol 2015; 8:777-83. [PMID: 26309879 DOI: 10.3980/j.issn.2222-3959.2015.04.24] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 01/08/2015] [Indexed: 01/09/2023] Open
Abstract
AIM To compare the effect of suction on the macular thickness and retinal nerve fiber layer (RNFL) thickness during laser in situ keratomileusis (LASIK) used Ziemer FEMTO LDV femtosecond laser (Ziemer group) and Moria M2 automated microkeratome (Moria group) for flap creation. METHODS Fourier-domain optical coherence tomography (FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and (RNFL) thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser (102 eyes) and the Moria M2 microkeratome (102 eyes) before surgery and 30min; 1, 3d; 1wk; 1, 3mo; 1y after surgery. RESULTS The average foveal thickness and parafoveal retinal thickness 30min after the surgery were statistically more than that before surgery (Ziemer P<0.001, P=0.003 and Moria P=0.001, P=0.006) and the effect was less in the Ziemer group than that in the Moria group (P all<0.05). The ganglion cell complex thickness was not significantly changed in both groups (P all>0.05). The RNFL thickness was statistically less 30min after surgery in both groups (P=0.014, P<0.001), but the influence was less in Ziemer group than that in Moria group (P=0.038). However, the RNFL thickness had recovered to the preoperative level only 1d after surgery. CONCLUSION The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.
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Affiliation(s)
- Jing Zhang
- Ophthalmic Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Yue-Hua Zhou
- Ophthalmic Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
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Zhi Z, Cepurna W, Johnson E, Jayaram H, Morrison J, Wang RK. Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT. Microvasc Res 2015; 101:86-95. [PMID: 26186381 DOI: 10.1016/j.mvr.2015.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/04/2015] [Accepted: 07/04/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE To determine if retinal capillary filling is preserved in the face of acutely elevated intraocular pressure (IOP) in anesthetized rats, despite a reduction in total retinal blood flow (RBF), using optical microangiography/optical coherence tomography (OMAG/OCT). METHODS OMAG provided the capability of depth-resolved imaging of the retinal microvasculature down to the capillary level. Doppler OCT was applied to measure the total RBF using an enface integration approach. The microvascular pattern, capillary density, and total RBF were monitored in vivo as the IOP was increased from 10 to 100mmHg in 10mmHg intervals and returned back to 10mmHg. RESULTS In animals with mean arterial pressure (MAP) of 102±4mmHg (n=10), when IOP was increased from 0 to 100mmHg, the capillary density remained at or above 80% of baseline for the IOP up to 60mmHg [or ocular perfusion pressure (OPP) at 40mmHg]. This was then decreased, achieving 60% of baseline at IOP 70mmHg and OPP of 30mmHg. Total RBF was unaffected by moderate increases in IOP up to 30mmHg, beyond which total RBF decreased linearly, reaching 50% of baseline at IOP 60mmHg and OPP 40mmHg. Both capillary density and total RBF were totally extinguished at 100mmHg, but fully recovered when IOP returned to baseline. By comparison, a separate group of animals with lower MAP (mean=75±6mmHg, n=7) demonstrated comparable decreases in both capillary filling and total RBF at IOPs that were 20mmHg lower than in the initial group. Both were totally extinguished at 80mmHg, but fully recovered when IOP returned to baseline. Relationships of both parameters to OPP were unchanged. CONCLUSION Retinal capillary filling and total RBF responses to IOP elevation can be monitored non-invasively by OMAG/OCT and both are influenced by OPP. Retinal capillary filling was relatively preserved down to a perfusion pressure of 40mmHg, despite a linear reduction in total RBF.
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Affiliation(s)
- Zhongwei Zhi
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - William Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Elaine Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Hari Jayaram
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - John Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA.
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Abstract
Glaucoma is increasingly recognized as a neurodegenerative disorder, characterized by the accelerated loss of retinal ganglion cells (RGCs) and their axons. Impaired axonal transport has been implicated as a pathogenic mechanism in a number of neurodegenerative diseases, including glaucoma. The long RGC axon, with its high metabolic demand and crucial role in conveying neurotrophic signals, relies heavily on intact axonal transport. In this mini review, we consider the evidence for transport disruption along RGCs in association with glaucoma and other intraocular pressure models. We give a brief overview of the axonal transport process and the methods by which it is assessed. Spatial and temporal patterns of axonal transport disruption are considered as well as the reversibility of these changes. Biomechanical, metabolic and cytoskeletal insults may underlie the development of axonal transport deficits, and there are multiple perspectives on the impact that transport disruption has on the RGC. Eliciting the role of impaired axonal transport in glaucoma pathogenesis may uncover novel therapeutic targets for protecting the optic nerve and preventing vision loss in glaucoma.
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Affiliation(s)
- Eamonn T Fahy
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Vicki Chrysostomou
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Jonathan G Crowston
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
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The non-human primate experimental glaucoma model. Exp Eye Res 2015; 141:57-73. [PMID: 26070984 DOI: 10.1016/j.exer.2015.06.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/03/2015] [Accepted: 06/06/2015] [Indexed: 01/05/2023]
Abstract
The purpose of this report is to summarize the current strengths and weaknesses of the non-human primate (NHP) experimental glaucoma (EG) model through sections devoted to its history, methods, important findings, alternative optic neuropathy models and future directions. NHP EG has become well established for studying human glaucoma in part because the NHP optic nerve head (ONH) shares a close anatomic association with the human ONH and because it provides the only means of systematically studying the very earliest visual system responses to chronic intraocular pressure (IOP) elevation, i.e. the conversion from ocular hypertension to glaucomatous damage. However, NHPs are impractical for studies that require large animal numbers, demonstrate spontaneous glaucoma only rarely, do not currently provide a model of the neuropathy at normal levels of IOP, and cannot easily be genetically manipulated, except through tissue-specific, viral vectors. The goal of this summary is to direct NHP EG and non-NHP EG investigators to the previous, current and future accomplishment of clinically relevant knowledge in this model.
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Nuschke AC, Farrell SR, Levesque JM, Chauhan BC. Assessment of retinal ganglion cell damage in glaucomatous optic neuropathy: Axon transport, injury and soma loss. Exp Eye Res 2015; 141:111-24. [PMID: 26070986 DOI: 10.1016/j.exer.2015.06.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/01/2015] [Accepted: 06/06/2015] [Indexed: 02/07/2023]
Abstract
Glaucoma is a disease characterized by progressive axonal pathology and death of retinal ganglion cells (RGCs), which causes structural changes in the optic nerve head and irreversible vision loss. Several experimental models of glaucomatous optic neuropathy (GON) have been developed, primarily in non-human primates and, more recently and commonly, in rodents. These models provide important research tools to study the mechanisms underlying glaucomatous damage. Moreover, experimental GON provides the ability to quantify and monitor risk factors leading to RGC loss such as the level of intraocular pressure, axonal health and the RGC population. Using these experimental models we are able to gain a better understanding of GON, which allows for the development of potential neuroprotective strategies. Here we review the advantages and disadvantages of the relevant and most often utilized methods for evaluating axonal degeneration and RGC loss in GON. Axonal pathology in GON includes functional disruption of axonal transport (AT) and structural degeneration. Horseradish peroxidase (HRP), rhodamine-B-isothiocyanate (RITC) and cholera toxin-B (CTB) fluorescent conjugates have proven to be effective reporters of AT. Also, immunohistochemistry (IHC) for endogenous AT-associated proteins is often used as an indicator of AT function. Similarly, structural degeneration of axons in GON can be investigated via changes in the activity and expression of key axonal enzymes and structural proteins. Assessment of axonal degeneration can be measured by direct quantification of axons, qualitative grading, or a combination of both methods. RGC loss is the most frequently quantified variable in studies of experimental GON. Retrograde tracers can be used to quantify RGC populations in rodents via application to the superior colliculus (SC). In addition, in situ IHC for RGC-specific proteins is a common method of RGC quantification used in many studies. Recently, transgenic mouse models that express fluorescent proteins under the Thy-1 promoter have been examined for their potential to provide specific and selective labeling of RGCs for the study of GON. While these methods represent important advances in assessing the structural and functional integrity of RGCs, each has its advantages and disadvantages; together they provide an extensive toolbox for the study of GON.
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Affiliation(s)
- Andrea C Nuschke
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Spring R Farrell
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Capital District Health Authority, Halifax, Nova Scotia, Canada
| | - Julie M Levesque
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada; Capital District Health Authority, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada.
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45
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Fortune B. In vivo imaging methods to assess glaucomatous optic neuropathy. Exp Eye Res 2015; 141:139-53. [PMID: 26048475 DOI: 10.1016/j.exer.2015.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 05/13/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
The goal of this review is to summarize the most common imaging methods currently applied for in vivo assessment of ocular structure in animal models of experimental glaucoma with an emphasis on translational relevance to clinical studies of the human disease. The most common techniques in current use include optical coherence tomography and scanning laser ophthalmoscopy. In reviewing the application of these and other imaging modalities to study glaucomatous optic neuropathy, this article is organized into three major sections: 1) imaging the optic nerve head, 2) imaging the retinal nerve fiber layer and 3) imaging retinal ganglion cell soma and dendrites. The article concludes with a brief section on possible future directions.
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Affiliation(s)
- Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, 1225 NE Second Avenue, Portland, OR 97232, USA.
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46
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Chen X, Zhu Y, Hu S, Zhu Y. Effects of timing of vitrectomy performed for open-globe injury patients on the thickness of retinal nerve fiber layer. Pak J Med Sci 2015; 31:100-4. [PMID: 25878623 PMCID: PMC4386166 DOI: 10.12669/pjms.311.6088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/30/2014] [Indexed: 02/01/2023] Open
Abstract
Objective: To study the effects of timing of vitrectomy performed for open-globe injury patients on the thickness of retinal nerve fiber layer (RNFL). Methods: A total of 120 patients with traumatic optic neuropathy (TON) were selected and divided into a treatment group and a control group by random draw (n=60). Vitrectomy was performed within one week upon injury for treatment group and after one week for control group. The thickness of RNFL was observed by optical coherence tomography. Results: All surgeries were conducted successfully, without severe complications. The best corrected visual acuity of treatment group surpassed that of control group one month after surgery, and treatment group had an obviously higher overall effective rate (95.0%) than control group did (81.7%). The incidence rate of postoperative complications in treatment group (6.7%) was significantly lower than that of control group (28.3%) (P<0.05). Logistic multivariate regression analysis showed that vitrectomy timing and postoperative complications were independent risk factors of prognosis (P<0.05). Both groups had significantly thinner RNFLs one week after surgery (P<0.05), and treatment group almost recovered within one month (P>0.05). Conclusion: Early vitrectomy effectively augmented the visual acuity of patients with TON, decreased complications, affected RNFL thickness reversibly, and improved prognosis.
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Affiliation(s)
- Xiaoming Chen
- Dr. Xiaoming Chen, Medical School of Yangtze University, Jingzhou 434000, Hubei Province, P. R. China
| | - Yanni Zhu
- Dr. Yanni Zhu, Medical School of Yangtze University, Jingzhou 434000, Hubei Province, P. R. China
| | - Shuqiong Hu
- Dr. Shuqiong Hu, Medical School of Yangtze University, Jingzhou 434000, Hubei Province, P. R. China
| | - Yanhua Zhu
- Dr. Yanhua Zhu, Medical School of Yangtze University, Jingzhou 434000, Hubei Province, P. R. China
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47
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An acute intraocular pressure challenge to assess retinal ganglion cell injury and recovery in the mouse. Exp Eye Res 2015; 141:3-8. [PMID: 25753840 DOI: 10.1016/j.exer.2015.03.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/03/2015] [Accepted: 03/06/2015] [Indexed: 11/23/2022]
Abstract
We describe a model of acute intraocular pressure (IOP) elevation in the mouse eye that induces reversible loss of inner retinal function associated with oxidative stress, glial cell activation and minimal loss of retinal ganglion cell (RGC) number. Young healthy mouse eyes recover inner retinal function within 7-days but more persistent functional loss is seen in older mice. Manipulation of diet and exercise further modify RGC recovery demonstrating the utility of this injury model for investigating lifestyle and therapeutic interventions. We believe that systematic investigation into the characteristics and determinants of RGC recovery following an IOP challenge will shed light on processes that govern RGC vulnerability in the early stages of glaucoma.
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Abbott CJ, Choe TE, Burgoyne CF, Cull G, Wang L, Fortune B. Comparison of retinal nerve fiber layer thickness in vivo and axonal transport after chronic intraocular pressure elevation in young versus older rats. PLoS One 2014; 9:e114546. [PMID: 25501362 PMCID: PMC4263742 DOI: 10.1371/journal.pone.0114546] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 11/11/2014] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To compare in young and old rats longitudinal measurements of retinal nerve fiber layer thickness (RNFLT) and axonal transport 3-weeks after chronic IOP elevation. METHOD IOP was elevated unilaterally in 2- and 9.5-month-old Brown-Norway rats by intracameral injections of magnetic microbeads. RNFLT was measured by spectral domain optical coherence tomography. Anterograde axonal transport was assessed from confocal scanning laser ophthalmolscopy of superior colliculi (SC) after bilateral intravitreal injections of cholera toxin-B-488. Optic nerve sections were graded for damage. RESULTS Mean IOP was elevated in both groups (young 37, old 38 mmHg, p = 0.95). RNFL in young rats exhibited 10% thickening at 1-week (50.9±8.1 µm, p<0.05) vs. baseline (46.4±2.4 µm), then 7% thinning at 2-weeks (43.0±7.2 µm, p>0.05) and 3-weeks (43.5±4.4 µm, p>0.05), representing 20% loss of dynamic range. RNFLT in old rats showed no significant change at 1-week (44.9±4.1 µm) vs. baseline (49.2±5.3 µm), but progression to 22% thinning at 2-weeks (38.0±3.7 µm, p<0.01) and 3-weeks (40.0±6.6 µm, p<0.05), representing 59% loss of dynamic range. Relative SC fluorescence intensity was reduced in both groups (p<0.001), representing 77-80% loss of dynamic range and a severe transport deficit. Optic nerves showed 75-95% damage (p<0.001). There was greater RNFL thinning in old rats (p<0.05), despite equivalent IOP insult, transport deficit and nerve damage between age groups (all p>0.05). CONCLUSION Chronic IOP elevation resulted in severely disrupted axonal transport and optic nerve axon damage in all rats, associated with mild RNFL loss in young rats but a moderate RNFL loss in old rats despite the similar IOP insult. Hence, the glaucomatous injury response within the RNFL depends on age.
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Affiliation(s)
- Carla J. Abbott
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Tiffany E. Choe
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Claude F. Burgoyne
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Grant Cull
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Lin Wang
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
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49
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Choe TE, Abbott CJ, Piper C, Wang L, Fortune B. Comparison of longitudinal in vivo measurements of retinal nerve fiber layer thickness and retinal ganglion cell density after optic nerve transection in rat. PLoS One 2014; 9:e113011. [PMID: 25393294 PMCID: PMC4231142 DOI: 10.1371/journal.pone.0113011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 10/23/2014] [Indexed: 11/23/2022] Open
Abstract
Purpose To determine the relationship between longitudinal in vivo measurements of retinal nerve fiber layer thickness (RNFLT) and retinal ganglion cell (RGC) density after unilateral optic nerve transection (ONT). Methods Nineteen adult Brown-Norway rats were studied; N = 10 ONT plus RGC label, N = 3 ONT plus vehicle only (sans label), N = 6 sham ONT plus RGC label. RNFLT was measured by spectral domain optical coherence tomography (SD-OCT) at baseline then weekly for 1 month. RGCs were labeled by retrograde transport of fluorescently conjugated cholera toxin B (CTB) from the superior colliculus 48 hours prior to ONT or sham surgery. RGC density measurements were obtained by confocal scanning laser ophthalmoscopy (CSLO) at baseline and weekly for 1 month. RGC density and reactivity of microglia (anti-Iba1) and astrocytes (anti-GFAP) were determined from post mortem fluorescence microscopy of whole-mount retinae. Results RNFLT decreased after ONT by 17% (p<0.05), 30% (p<0.0001) and 36% (p<0.0001) at weeks 2, 3 and 4. RGC density decreased after ONT by 18%, 69%, 85% and 92% at weeks 1, 2, 3 and 4 (p<0.0001 each). RGC density measured in vivo at week 4 and post mortem by microscopy were strongly correlated (R = 0.91, p<0.0001). In vivo measures of RNFLT and RGC density were strongly correlated (R = 0.81, p<0.0001). In ONT- CTB labeled fellow eyes, RNFLT increased by 18%, 52% and 36% at weeks 2, 3 and 4 (p<0.0001), but did not change in fellow ONT-eyes sans CTB. Microgliosis was evident in the RNFL of the ONT-CTB fellow eyes, exceeding that observed in other fellow eyes. Conclusions In vivo measurements of RNFLT and RGC density are strongly correlated and can be used to monitor longitudinal changes after optic nerve injury. The strong fellow eye effect observed in eyes contralateral to ONT, only in the presence of CTB label, consisted of a dramatic increase in RNFLT associated with retinal microgliosis.
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Affiliation(s)
- Tiffany E. Choe
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Carla J. Abbott
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Chelsea Piper
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Lin Wang
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, Oregon, United States of America
- * E-mail:
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50
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Dengler-Crish CM, Smith MA, Inman DM, Wilson GN, Young JW, Crish SD. Anterograde transport blockade precedes deficits in retrograde transport in the visual projection of the DBA/2J mouse model of glaucoma. Front Neurosci 2014; 8:290. [PMID: 25278826 PMCID: PMC4166356 DOI: 10.3389/fnins.2014.00290] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/27/2014] [Indexed: 01/30/2023] Open
Abstract
Axonal transport deficits have been reported as an early pathology in several neurodegenerative disorders, including glaucoma. However, the progression and mechanisms of these deficits are poorly understood. Previous work suggests that anterograde transport is affected earlier and to a larger degree than retrograde transport, yet this has never been examined directly in vivo. Using combined anterograde and retrograde tract tracing methods, we examined the time-course of anterograde and retrograde transport deficits in the retinofugal projection in pre-glaucomatous (3 month-old) and glaucomatous (9–13 month old) DBA/2J mice. DBA/2J-Gpnmb+ mice were used as a control strain and were shown to have similar retinal ganglion cell densities as C57BL/6J control mice—a strain commonly investigated in the field of vision research. Using cholera toxin-B injections into the eye and FluoroGold injections into the superior colliculus (SC), we were able to measure anterograde and retrograde transport in the primary visual projection. In DBA/2J, anterograde transport from the retina to SC was decreased by 69% in the 9–10 month-old age group, while retrograde transport was only reduced by 23% from levels seen in pre-glaucomatous mice. Despite this minor reduction, retrograde transport remained largely intact in these glaucomatous age groups until 13-months of age. These findings indicate that axonal transport deficits occur in semi-functional axons that are still connected to their brain targets. Structural persistence as determined by presence of estrogen-related receptor beta label in the superficial SC was maintained beyond time-points where reductions in retrograde transport occurred, also supporting that transport deficits may be due to physiological or functional abnormalities as opposed to overt structural loss.
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Affiliation(s)
- Christine M Dengler-Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University Rootstown, OH, USA ; Department of Anatomy and Neurobiology, Northeast Ohio Medical University Rootstown, OH, USA
| | - Matthew A Smith
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University Rootstown, OH, USA ; Integrated Pharmaceutical Medicine Graduate Program, Northeast Ohio Medical University Rootstown, OH, USA
| | - Denise M Inman
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University Rootstown, OH, USA
| | - Gina N Wilson
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University Rootstown, OH, USA ; Biomedical Sciences Graduate Program, Kent State University Kent, OH, USA
| | - Jesse W Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University Rootstown, OH, USA
| | - Samuel D Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University Rootstown, OH, USA
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