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Bhuckory MB, Wang BY, Chen ZC, Shin A, Pham-Howard D, Shah S, Monkongpitukkul N, Galambos L, Kamins T, Mathieson K, Palanker D. 3D electronic implants in subretinal space: Long-term follow-up in rodents. Biomaterials 2024; 311:122674. [PMID: 38897028 PMCID: PMC11298295 DOI: 10.1016/j.biomaterials.2024.122674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 06/12/2024] [Accepted: 06/15/2024] [Indexed: 06/21/2024]
Abstract
Clinical results with photovoltaic subretinal prosthesis (PRIMA) demonstrated restoration of sight via electrical stimulation of the interneurons in degenerated retina, with resolution matching the 100 μm pixel size. Since scaling the pixels below 75 μm in the current bipolar planar geometry will significantly limit the penetration depth of the electric field and increase stimulation threshold, we explore the possibility of using smaller pixels based on a novel 3-dimensional honeycomb-shaped design. We assessed the long-term biocompatibility and stability of these arrays in rats by investigating the anatomical integration of the retina with flat and 3D implants and response to electrical stimulation over lifetime - up to 32-36 weeks post-implantation in aged rats. With both flat and 3D implants, signals elicited in the visual cortex decreased after the day of implantation by more than 3-fold, and gradually recovered over the next 12-16 weeks. With 25 μm high honeycomb walls, the majority of bipolar cells migrate into the wells, while amacrine and ganglion cells remain above the cavities, which is essential for selective network-mediated stimulation of the retina. Retinal thickness and full-field stimulation threshold with 40 μm-wide honeycomb pixels were comparable to those with planar devices - 0.05 mW/mm2 with 10 ms pulses. However, fewer cells from the inner nuclear layer migrated into the 20 μm-wide wells, and stimulation threshold increased over 12-16 weeks, before stabilizing at about 0.08 mW/mm2. Such threshold is still significantly lower than 1.8 mW/mm2 with a previous design of flat bipolar pixels, confirming the promise of the 3D honeycomb-based approach to high resolution subretinal prosthesis.
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Affiliation(s)
- Mohajeet B Bhuckory
- Department of Ophthalmology, Stanford University, Stanford, CA, USA; Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA.
| | - Bing-Yi Wang
- Department of Physics, Stanford University, Stanford, CA, USA
| | - Zhijie C Chen
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Andrew Shin
- Department of Material Science, Stanford University, Stanford, CA, USA
| | - Davis Pham-Howard
- Department of Ophthalmology, Stanford University, Stanford, CA, USA; Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
| | - Sarthak Shah
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
| | - Nicharee Monkongpitukkul
- Department of Ophthalmology, Stanford University, Stanford, CA, USA; Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
| | - Ludwig Galambos
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
| | - Theodore Kamins
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA; Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Keith Mathieson
- Department of Physics, Institute of Photonics, University of Strathclyde, Glasgow, Scotland, UK
| | - Daniel Palanker
- Department of Ophthalmology, Stanford University, Stanford, CA, USA; Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
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Rajendran Nair DS, Camarillo JCM, Lu G, Thomas BB. Measuring spatial visual loss in rats by retinotopic mapping of the superior colliculus using a novel multi-electrode array technique. J Neurosci Methods 2024; 405:110095. [PMID: 38403001 PMCID: PMC11363873 DOI: 10.1016/j.jneumeth.2024.110095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/06/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND The retinotopic map property of the superior colliculus (SC) is a reliable indicator of visual functional changes in rodents. Electrophysiological mapping of the SC using a single electrode has been employed for measuring visual function in rat and mouse disease models. Single electrode mapping is highly laborious requiring long-term exposure to the SC surface and prolonged anesthetic conditions that can adversely affect the mapping data. NEW METHOD To avoid the above-mentioned issues, we fabricated a fifty-six (56) electrode multi-electrode array (MEA) for rapid and reliable visual functional mapping of the SC. Since SC is a dome-shaped structure, the array was made of electrodes with dissimilar tip lengths to enable simultaneous and uniform penetration of the SC. RESULTS SC mapping using the new MEA was conducted in retinal degenerate (RD) Royal College of Surgeons (RCS) rats and rats with focal retinal damage induced by green diode laser. For SC mapping, the MEA was advanced into the SC surface and the visual activities were recorded during full-filed light stimulation of the eye. Based on the morphological examination, the MEA electrodes covered most of the exposed SC area and penetrated the SC surface at a relatively uniform depth. MEA mapping in RCS rats (n=9) demonstrated progressive development of a scotoma in the SC that corresponded to the degree of photoreceptor loss. MEA mapping in the laser damaged rats demonstrated the presence of a scotoma in the SC area that corresponded to the location of retinal laser injury. COMPARISON WITH EXISTING METHODS AND CONCLUSIONS The use of MEA for SC mapping is advantageous over single electrode recording by enabling faster recordings and reducing anesthesia time. This study establishes the feasibility of the MEA technique for rapid and efficient SC mapping, particularly advantageous for evaluating therapeutic effects in retinal degenerate rat disease models.
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Affiliation(s)
- Deepthi S Rajendran Nair
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States
| | - Juan Carlos-Martinez Camarillo
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, United States
| | - Gengxi Lu
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States
| | - Biju B Thomas
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, United States.
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Azrad Leibovitch T, Farah N, Markus A, Mandel Y. A novel GCaMP6f-RCS rat model for studying electrical stimulation in the degenerated retina. Front Cell Dev Biol 2024; 12:1386141. [PMID: 38711618 PMCID: PMC11070775 DOI: 10.3389/fcell.2024.1386141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/25/2024] [Indexed: 05/08/2024] Open
Abstract
Background: Retinal prostheses aim to restore vision by electrically stimulating the remaining viable retinal cells in Retinal Degeneration (RD) cases. Research in this field necessitates a comprehensive analysis of retinal ganglion cells' (RGCs) responses to assess the obtained visual acuity and quality. Here we present a novel animal model which facilitates the optical recording of RGCs activity in an RD rat. This model can significantly enhance the functional evaluation of vision restoration treatments. Methods: The development of the novel rat model is based on crossbreeding a retinal degenerated Royal College of Surgeons (RCS) rat with a transgenic line expressing the genetic calcium indicator GCaMP6f in the RGCs. Characterization of the model was achieved using Optical Coherence Tomography (OCT) imaging, histology, and electroretinography (ERG) at the ages of 4, 8, and 12 weeks. Additionally, optical recordings of RGCs function in response to ex-vivo subretinal electrical stimulations were performed. Results: Histological investigations confirmed the high expression of GCaMP6f in the RGCs and minimal expression in the inner nuclear layer (INL). OCT imaging and histological studies revealed the expected gradual retinal degeneration, as evident by the decrease in retinal thickness with age and the formation of subretinal debris. This degeneration was further confirmed by ERG recordings, which demonstrated a significant decrease in the b-wave amplitude throughout the degeneration process, culminating in its absence at 12 weeks in the GCaMP6f-RCS rat. Importantly, the feasibility of investigating subretinal stimulation was demonstrated, revealing a consistent increase in activation threshold throughout degeneration. Furthermore, an increase in the diameter of the activated area with increasing currents was observed. The spatial spread of the activation area in the GCaMP6f-RCS rat was found to be smaller and exhibited faster activation dynamics compared with the GCaMP6f-LE strain. Conclusion: This novel animal model offers an opportunity to deepen our understanding of prosthetically induced retinal responses, potentially leading to significant advancements in prosthetic interventions in visual impairments.
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Affiliation(s)
- Tamar Azrad Leibovitch
- Bar Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
- Faculty of Life Sciences, School of Optometry and Visual Science, Bar Ilan University, Ramat Gan, Israel
| | - Nairouz Farah
- Bar Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
- Faculty of Life Sciences, School of Optometry and Visual Science, Bar Ilan University, Ramat Gan, Israel
| | - Amos Markus
- Bar Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
- Faculty of Life Sciences, School of Optometry and Visual Science, Bar Ilan University, Ramat Gan, Israel
| | - Yossi Mandel
- Bar Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
- Faculty of Life Sciences, School of Optometry and Visual Science, Bar Ilan University, Ramat Gan, Israel
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Wang B, Arbuckle RK, Davoli KA, Clinger OD, Brown R, Sahel JA, Chen Y, Pi S. Compensation of inner retina to early-stage photoreceptor degeneration in a Rho P23H/+ mouse model of retinitis pigmentosa. Exp Eye Res 2024; 240:109826. [PMID: 38340947 PMCID: PMC10940204 DOI: 10.1016/j.exer.2024.109826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024]
Abstract
Retinitis pigmentosa (RP) is an inherited retinal disorder characterized by the degeneration of photoreceptors. RhoP23H/+ mice, which carry a Pro23His mutation in the RHODOPSIN (Rho) gene, are one of the most studied animal models for RP. However, except for the photoreceptors, other retinal neural cells have not been fully investigated in this model. Here, we record the temporal changes of the retina by optical coherence tomography (OCT) imaging of the RhoP23H/+ mice, from early to mid-phase of retinal degeneration. Based on thickness analysis, we identified a natural retinal thickness adaption in wild-type mice during early adulthood and observed morphological compensation of the inner retina layer to photoreceptor degeneration in the RhoP23H/+ mice, primarily on the inner nuclear layer (INL). RhoP23H/+ mice findings were further validated via: histology showing the negative correlation of INL and ONL thicknesses; as well as electroretinogram (ERG) showing an increased b-wave to a-wave ratio. These results unravel the sequential morphologic events in this model and suggest a better understanding of retinal degeneration of RP for future studies.
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Affiliation(s)
- Bingjie Wang
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Riley K Arbuckle
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, 15213, USA
| | - Katherine A Davoli
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Owen D Clinger
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Richard Brown
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - José-Alain Sahel
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Yuanyuan Chen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
| | - Shaohua Pi
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; UPMC Vision Institute, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
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Hui Q, Yang N, Xiong C, Zhou S, Zhou X, Jin Q, Xu X. Isorhamnetin suppresses the epithelial-mesenchymal transition of the retinal pigment epithelium both in vivo and in vitro through Nrf2-dependent AKT/GSK-3β pathway. Exp Eye Res 2024; 240:109823. [PMID: 38331017 DOI: 10.1016/j.exer.2024.109823] [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: 11/18/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
Age-related macular degeneration (AMD) is a major cause of blindness in the elderly worldwide. Multiple studies have shown that epithelial-mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of AMD. Isorhamnetin (Isor) is a flavonoid compound that inhibits EMT in tumor cells. However, whether it can also attenuate EMT in the retinal pigment epithelium (RPE) is unknown. Therefore, our study was designed to probe the possible impact of Isor on EMT process in both mouse retina and ARPE-19 cells. C57BL/6 mice were utilized to establish a dry AMD model. Isor and LCZ (a mixture of luteine/β-carotene/zinc gluconate) were administered orally for 3 months. The effects of Isor on the retina were evaluated using fundus autofluorescence, optical coherence tomography, and transmission electron microscopy. Transwell and wound healing assay were employed to assess ARPE-19 cell migration. Western blotting and immunofluorescence were used to measure the protein expressions associated with EMT, Nrf2 and AKT/GSK-3β pathway. The findings indicated that Isor alleviated dry AMD-like pathological changes in vehicle mice retina, inhibited the migration of Ox-LDL-treated ARPE-19 cells, and repressed the EMT processes in vivo and in vitro. Furthermore, Isor activated Nrf2 pathway and deactivated AKT/GSK-3β pathway in both vehicle mice and ARPE-19 cells. Interestingly, when Nrf2 siRNA was transfected into ARPE-19 cells, the inhibitory effect of Isor on EMT and AKT/GSK-3β pathway was attenuated. These results suggested that Isor inhibited EMT processes via Nrf2-dependent AKT/GSK-3β pathway and is a promising candidate for dry AMD treatment.
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Affiliation(s)
- Qinyi Hui
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Ning Yang
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Caijian Xiong
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Siqi Zhou
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Xin Zhou
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Qingzi Jin
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China
| | - Xinrong Xu
- Department of Ophthalmology, Jiangsu Province Hospital of Chinese Medicine (Affiliated Hospital of Nanjing University of Chinese Medicine), Nanjing, 210029, China.
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Zhang ZJ, Wu YR, Chien Y, Chen Y, Chiou SH, Chen SJ, Syu JP, Kuo WC. Quantification of microvascular change of retinal degeneration in Royal College of Surgeons rats using high-resolution spectral domain optical coherence tomography angiography. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:106001. [PMID: 37841506 PMCID: PMC10570624 DOI: 10.1117/1.jbo.28.10.106001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 10/17/2023]
Abstract
Significance For research on retinitis pigmentosa in humans, the Royal College of Surgeons (RCS) rat is commonly used as the primary animal model since the disease process is similar. Therefore, it is necessary to understand how the disease develops and determine whether the treatment is effective. Aim In this study, structural and microvascular change of retinal degeneration in RCS rats was assessed non-invasively on specific dates over 3.5 months. Approach Using a high-resolution spectral domain (SD) optical coherence tomography angiography (OCTA), the retinal degeneration in RCS rats, from day 14 until day 126, was qualitatively and quantitatively analyzed. Results Aside from the thinning of the retina thickness starting from 2 weeks of age, blood vessels in the deep layer of the retina also began to degenerate at about 4 weeks of age. Hole structures appeared at the inner nuclear layer and the inner plexiform layer by the age of 10 weeks. Observations of abnormal angiogenesis in the choroid began by 12 weeks of age. Conclusions We conducted a longitudinal study of retina degeneration structure and vascular changes in an RCS rat model using a supercontinuum laser based high-resolution SD-OCTA. Combined with OCTA, OCT leads to a better understanding of photoreceptor pathology as retinal degeneration by identifying tissue and vessel loss.
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Affiliation(s)
- Zhen-Jie Zhang
- National Yang Ming Chiao Tung University, Institute of Biophotonics, Taipei, Taiwan
| | - You-Ren Wu
- Taipei Veterans General Hospital, Department of Medical Research, Taipei, Taiwan
- National Yang Ming Chiao Tung University, Institute of Pharmacology, Taipei, Taiwan
| | - Yueh Chien
- Taipei Veterans General Hospital, Department of Medical Research, Taipei, Taiwan
- National Yang Ming Chiao Tung University, Institute of Pharmacology, Taipei, Taiwan
| | - Yang Chen
- National Yang Ming Chiao Tung University, Institute of Biophotonics, Taipei, Taiwan
| | - Shih-Hwa Chiou
- Taipei Veterans General Hospital, Department of Medical Research, Taipei, Taiwan
- National Yang Ming Chiao Tung University, Institute of Pharmacology, Taipei, Taiwan
- Taipei Veterans General Hospital, Department of Ophthalmology, Taiwan
| | - Shih-Jen Chen
- Taipei Veterans General Hospital, Department of Ophthalmology, Taiwan
- National Yang Ming Chiao Tung University, School of Medicine, Taiwan
| | - Jia-Pu Syu
- National Yang Ming Chiao Tung University, Institute of Biophotonics, Taipei, Taiwan
| | - Wen-Chuan Kuo
- National Yang Ming Chiao Tung University, Institute of Biophotonics, Taipei, Taiwan
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Gaston G, Babcock S, Ryals R, Elizondo G, DeVine T, Wafai D, Packwood W, Holden S, Raber J, Lindner JR, Pennesi ME, Harding CO, Gillingham MB. A G1528C Hadha knock-in mouse model recapitulates aspects of human clinical phenotypes for long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency. Commun Biol 2023; 6:890. [PMID: 37644104 PMCID: PMC10465608 DOI: 10.1038/s42003-023-05268-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 08/21/2023] [Indexed: 08/31/2023] Open
Abstract
Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a fatty acid oxidation disorder (FAOD) caused by a pathogenic variant, c.1528 G > C, in HADHA encoding the alpha subunit of trifunctional protein (TFPα). Individuals with LCHADD develop chorioretinopathy and peripheral neuropathy not observed in other FAODs in addition to the more ubiquitous symptoms of hypoketotic hypoglycemia, rhabdomyolysis and cardiomyopathy. We report a CRISPR/Cas9 generated knock-in murine model of G1528C in Hadha that recapitulates aspects of the human LCHADD phenotype. Homozygous pups are less numerous than expected from Mendelian probability, but survivors exhibit similar viability with wildtype (WT) littermates. Tissues of LCHADD homozygotes express TFPα protein, but LCHADD mice oxidize less fat and accumulate plasma 3-hydroxyacylcarnitines compared to WT mice. LCHADD mice exhibit lower ketones with fasting, exhaust earlier during treadmill exercise and develop a dilated cardiomyopathy compared to WT mice. In addition, LCHADD mice exhibit decreased visual performance, decreased cone function, and disruption of retinal pigment epithelium. Neurological function is affected, with impaired motor function during wire hang test and reduced open field activity. The G1528C knock-in mouse exhibits a phenotype similar to that observed in human patients; this model will be useful to explore pathophysiology and treatments for LCHADD in the future.
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Affiliation(s)
- Garen Gaston
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Shannon Babcock
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Renee Ryals
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - Gabriela Elizondo
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Tiffany DeVine
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Dahlia Wafai
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - William Packwood
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Sarah Holden
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
| | - Jacob Raber
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
- Departments of Neurology and Radiation Medicine, Oregon Health and Science University, Portland, OR, USA
- Division of Neuroscience, Oregon National Primate Research Center (ONPRC), Oregon Health and Science University, Portland, OR, USA
| | - Jonathan R Lindner
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Cardiovascular Division, University of Virginia Medical Center, Charlottesville, VA, USA
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Melanie B Gillingham
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA.
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Su Q, Dong J, Zhang D, Yang L, Roy R. Protective Effects of the Bilobalide on Retinal Oxidative Stress and Inflammation in Streptozotocin-Induced Diabetic Rats. Appl Biochem Biotechnol 2022; 194:6407-6422. [PMID: 35932369 DOI: 10.1007/s12010-022-04012-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2022] [Indexed: 12/01/2022]
Abstract
Diabetic retinopathy (DR) is a diabetes mellitus (DM) complication that causes visual acuity impairment and loss of sight in the working population, mainly in developed countries. According to the WHO, DR accounts for 5% of the world's 37 million blind people. The prevalence of diabetic retinopathy was highest in Africa, followed by North America and the Caribbean and South and Central America. Hyperglycemia can generate excessive ROS that activates multiple pathways, which can damage the cells. Oxidative stress and inflammatory process are intricate in the DR pathological mechanism. Bilobalide is the main bioactive compound isolated from the Ginkgo biloba, a plant utilized in folklore medicine. Bilobalide, a sesquiterpene trilactone, exhibits excellent antioxidant activity. But the molecular mechanisms associated with such effects, especially the antioxidant-related mechanism, have not been documented. Hence, this investigation explored whether bilobalide may attenuate DR in streptozotocin (STZ)-prompted diabetic rats. The effects of bilobalide on parameters of antioxidant content, oxidative stress, and inflammatory factors in the retinal tissues were evaluated by ELISA, RT-PCR, and immunohistochemistry methods. Bilobalide improved caloric management by reducing food consumption and increasing body weight. Furthermore, the administration of bilobalide decreases the blood glucose level and glycosylated (HbA1c) hemoglobin. The anti-retinopathy activity of bilobalide was established by the increase in the total retina thickness (TRT), inner nuclear layer (INL), and outer nuclear layer (ONL) in diabetic rats. Additionally, the serum level of MDA was decreased. In contrast, the antioxidant enzyme (SOD and CAT) levels were increased with TAC plus lower Keap1 and higher Nrf2 expression in the retina when associated with the DM rats. Moreover, bilobalide increased the nuclear factor erythroid 2-related factor 2 (Nrf2) and Heme oxygenase-1 (HO-1) expression level and inflammatory mediators (NF-κβ p65, TNF-α, IL-1β, and VEGF), thus inhibiting oxidative stress. Bilobalide can be effective against DR, and the possible mechanism may be relatively elucidated by decreasing oxidative stress and anti-inflammatory activities. But the further investigation should be directed to expose the precise mechanism.
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Affiliation(s)
- Qiang Su
- Department of Ophthalmology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China.
| | - Jing Dong
- Department of Ophthalmology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Donglei Zhang
- Department of Ophthalmology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Lu Yang
- Department of Retinology, Shanxi Eye Hospital, Taiyuan, 030001, China
| | - Rupak Roy
- SHRM Biotechnologies Pvt. Ltd. Kolkata, Kolkata, West Bengal, India
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Chauhan P, Kho AM, FitzGerald P, Shibata B, Srinivasan VJ. Subcellular Comparison of Visible-Light Optical Coherence Tomography and Electron Microscopy in the Mouse Outer Retina. Invest Ophthalmol Vis Sci 2022; 63:10. [PMID: 35943734 PMCID: PMC9379865 DOI: 10.1167/iovs.63.9.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/30/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose We employed in vivo, 1.0-µm axial resolution visible-light optical coherence tomography (OCT) and ex vivo electron microscopy (EM) to investigate three subcellular features in the mouse outer retina: reflectivity oscillations inner to band 1 (study 1); hyperreflective band 2, attributed to the ellipsoid zone or inner segment/outer segment (IS/OS) junction (study 2); and the hyperreflective retinal pigment epithelium (RPE) within band 4 (study 3). Methods Pigmented (C57BL/6J, n = 10) and albino (BALB/cJ, n = 3) mice were imaged in vivo. Enucleated eyes were processed for light and electron microscopy. Using well-accepted reference surfaces, we compared micrometer-scale axial reflectivity of visible-light OCT with subcellular organization, as revealed by 9449 annotated EM organelles and features across four pigmented eyes. Results In study 1, outer nuclear layer reflectivity peaks coincided with valleys in heterochromatin clump density (-0.34 ± 2.27 µm limits of agreement [LoA]). In study 2, band 2 depth on OCT and IS/OS junction depth on EM agreed (-0.57 ± 0.76 µm LoA), with both having similar distributions. In study 3, RPE electron dense organelle distribution did not agree with reflectivity in C57BL/6J mice, with OCT measures of RPE thickness exceeding those of EM (2.09 ± 0.89 µm LoA). Finally, RPE thickness increased with age in pigmented mice (slope = 0.056 µm/mo; P = 6.8 × 10-7). Conclusions Visible-light OCT bands arise from subcellular organization, enabling new measurements in mice. Quantitative OCT-EM comparisons may be confounded by hydration level, particularly in the OS and RPE. Caution is warranted in generalizing results to other species.
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Affiliation(s)
- Pooja Chauhan
- Department of Radiology, NYU Langone Health, New York, New York, United States
| | - Aaron M. Kho
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States
| | - Paul FitzGerald
- Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States
| | - Bradley Shibata
- Biological Electron Microscopy Facility, University of California Davis, Davis, California, United States
| | - Vivek J. Srinivasan
- Department of Radiology, NYU Langone Health, New York, New York, United States
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States
- Department of Ophthalmology, NYU Langone Health, New York, New York, United States
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Hadady H, Karamali F, Ejeian F, Soroushzadeh S, Nasr-Esfahani MH. Potential neuroprotective effect of stem cells from apical papilla derived extracellular vesicles enriched by lab-on-chip approach during retinal degeneration. Cell Mol Life Sci 2022; 79:350. [PMID: 35672609 PMCID: PMC11071776 DOI: 10.1007/s00018-022-04375-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/24/2022] [Accepted: 05/12/2022] [Indexed: 11/03/2022]
Abstract
Retinal degeneration (RD) is recognized as a frequent cause of visual impairments, including inherited (Retinitis pigmentosa) and degenerative (age-related macular) eye diseases. Dental stem cells (DSCs) have recently demonstrated a promising neuroprotection potential for ocular diseases through a paracrine manner carried out by extracellular vesicles (EVs). However, effective isolation of EVs is still challenging, and isolation methods determine the composition of enriched EVs and the subsequent biological and functional effects. In the present study, we assessed two enrichment methods (micro-electromechanical systems and ultrafiltration) to isolate the EVs from stem cells from apical papilla (SCAP). The size distribution of the corresponding isolates exhibited the capability of each method to enrich different subsets of EVs, which significantly impacts their biological and functional effects. We confirmed the neuroprotection and anti-inflammatory capacity of the SCAP-EVs in vitro. Further experiments revealed the possible therapeutic effects of subretinal injection of SCAP-EVs in the Royal College of Surgeons (RCS) rat model. We found that EVs enriched by the micro-electromechanical-based device (MEMS-EVs) preserved visual function, reduced retinal cell apoptosis, and prevented thinning of the outer nuclear layer (ONL). Interestingly, the effect of MEMS-EVs was extended to the retinal ganglion cell/retinal nerve fiber layer (GCL/RNFL). This study supports the use of the microfluidics approach to enrich valuable subsets of EVs, together with the choice of SCAP as a source to derive EVs for cell-free therapy of RD.
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Affiliation(s)
- Hanieh Hadady
- Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Fereshteh Karamali
- Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
| | - Fatemeh Ejeian
- Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr-Esfahani
- Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
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11
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Cho H, Jeong M, Lee S, Yoo S. Comparison of the qualitative and quantitative optical coherence tomographic features between sudden acquired retinal degeneration syndrome and normal eyes in dogs. Vet Ophthalmol 2022; 25 Suppl 1:144-163. [PMID: 35144323 DOI: 10.1111/vop.12975] [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: 11/04/2020] [Revised: 01/03/2022] [Accepted: 01/23/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To quantitatively and qualitatively characterize the retinal optical coherence tomographic features of sudden acquired retinal degeneration syndrome (SARDS) and SARDS suspect dogs. ANIMALS STUDIED Fourteen SARDS affected dogs, 11 age-, breed-, and sex-matched control dogs, and two SARDS suspect dogs. PROCEDURES Spectral-domain optical coherence tomography (OCT) images were used to evaluate the quantitative features, including thickness, intereye asymmetry, and longitudinal changes in retinal layer thickness and the qualitative features, including retinal architecture and vitreous haze. RESULTS Mean outer retinal layer thickness (ORT), outer nuclear layer thickness (ONL), and photoreceptor layer thickness (PRL) were significantly lower in the SARDS group, whereas mean inner retinal layer thickness was significantly higher in the SARDS group than in the control group. While thickness values of all retinal layers did not differ significantly between paired eyes in each group, the absolute intereye asymmetries in the ORT (p < .0001), ONL (p = .008), and PRL (p < .0001) were significantly higher in the SARDS group than in the control group. Some SARDS patients and SARDS suspects had a greater PRL than the control group, and serial OCT evaluation showed an increase in PRL in one SARDS suspect. Vitreous haze severity was greater in the SARDS group than in the control group (vitreous relative intensity, p = .030). CONCLUSIONS We described the OCT features of SARDS patients and suspects. In particular, PRL thickening in the SARDS suspects might indicate an early change in SARDS. Although further studies are needed, this finding might provide new insights into the pathogenesis of SARDS.
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12
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Ni S, Khan S, Nguyen TTP, Ng R, Lujan BJ, Tan O, Huang D, Jian Y. Volumetric directional optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:950-961. [PMID: 35284155 PMCID: PMC8884206 DOI: 10.1364/boe.447882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Photoreceptor loss and resultant thinning of the outer nuclear layer (ONL) is an important pathological feature of retinal degenerations and may serve as a useful imaging biomarker for age-related macular degeneration. However, the demarcation between the ONL and the adjacent Henle's fiber layer (HFL) is difficult to visualize with standard optical coherence tomography (OCT). A dedicated OCT system that can precisely control and continuously and synchronously update the imaging beam entry points during scanning has not been realized yet. In this paper, we introduce a novel imaging technology, Volumetric Directional OCT (VD-OCT), which can dynamically adjust the incident beam on the pupil without manual adjustment during a volumetric OCT scan. We also implement a customized spoke-circular scanning pattern to observe the appearance of HFL with sufficient optical contrast in continuous cross-sectional scans through the entire volume. The application of VD-OCT for retinal imaging to exploit directional reflectivity properties of tissue layers has the potential to allow for early identification of retinal diseases.
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Affiliation(s)
- Shuibin Ni
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Shanjida Khan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Thanh-Tin P. Nguyen
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Ringo Ng
- School of Engineering Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Brandon J. Lujan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
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13
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Zhang D, Mihai DM, Washington I. Vitamin A cycle byproducts explain retinal damage and molecular changes thought to initiate retinal degeneration. Biol Open 2021; 10:273577. [PMID: 34842275 PMCID: PMC8649638 DOI: 10.1242/bio.058600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/03/2021] [Indexed: 01/24/2023] Open
Abstract
In the most prevalent retinal diseases, including Stargardt disease and age-related macular degeneration (AMD), byproducts of vitamin A form in the retina abnormally during the vitamin A cycle. Despite evidence of their toxicity, whether these vitamin A cycle byproducts contribute to retinal disease, are symptoms, beneficial, or benign has been debated. We delivered a representative vitamin A byproduct, A2E, to the rat's retina and monitored electrophysiological, histological, proteomic, and transcriptomic changes. We show that the vitamin A cycle byproduct is sufficient alone to damage the RPE, photoreceptor inner and outer segments, and the outer plexiform layer, cause the formation of sub-retinal debris, alter transcription and protein synthesis, and diminish retinal function. The presented data are consistent with the theory that the formation of vitamin A byproducts during the vitamin A cycle is neither benign nor beneficial but may be sufficient alone to cause the most prevalent forms of retinal disease. Retarding the formation of vitamin A byproducts could potentially address the root cause of several retinal diseases to eliminate the threat of irreversible blindness for millions of people. Summary: During the vitamin A cycle, byproducts of vitamin A form in the eye. Using a rat model, we show that the byproducts alone can explain several retinal derangements observed in the prodromal phase of human retinal disease. Retarding the formation of these byproducts may address the root cause of the most prevalent retinal diseases.
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Affiliation(s)
- Dan Zhang
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Doina M Mihai
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA.,biOOrg3.14, Buffalo, WY 82834, USA
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14
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Koster C, van den Hurk KT, Lewallen CF, Talib M, ten Brink JB, Boon CJF, Bergen AA. The Lrat -/- Rat: CRISPR/Cas9 Construction and Phenotyping of a New Animal Model for Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22137234. [PMID: 34281288 PMCID: PMC8267968 DOI: 10.3390/ijms22137234] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
PURPOSE We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group harboring a homologous homozygous frameshift mutation in the LRAT gene (c.12delC), causing a dysfunctional visual (retinoid) cycle. METHODS The introduced mutation was confirmed by DNA and RNA sequencing. The expression of Lrat was determined on both the RNA and protein level in wildtype and knockout animals using RT-PCR and immunohistochemistry. The retinal structure and function, as well as the visual behavior of the Lrat-/- and control rats, were characterized using scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), electroretinography (ERG) and vision-based behavioral assays. RESULTS Wildtype animals had high Lrat mRNA expression in multiple tissues, including the eye and liver. In contrast, hardly any expression was detected in Lrat-/- animals. LRAT protein was abundantly present in wildtype animals and absent in Lrat-/- animals. Lrat-/- animals showed progressively reduced ERG potentials compared to wildtype controls from two weeks of age onwards. Vison-based behavioral assays confirmed reduced vision. Structural abnormalities, such as overall retinal thinning, were observed in Lrat-/- animals. The retinal thickness in knockout rats was decreased to roughly 80% by four months of age. No functional or structural differences were observed between wildtype and heterozygote animals. CONCLUSIONS Our Lrat-/- rat is a new animal model for retinal dystrophy, especially for the LRAT-subtype of early-onset retinal dystrophies. This model has advantages over the existing mouse models and the RCS rat strain and can be used for translational studies of retinal dystrophies.
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Affiliation(s)
- Céline Koster
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Koen T. van den Hurk
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Colby F. Lewallen
- Georgia Institute of Technology, G.W. Woodruff School of Mechanical Engineering, Atlanta, GA 30313, USA;
| | - Mays Talib
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (M.T.); (C.J.F.B.)
| | - Jacoline B. ten Brink
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Camiel J. F. Boon
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (M.T.); (C.J.F.B.)
- Department of Ophthalmology, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands
| | - Arthur A. Bergen
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
- Department of Ophthalmology, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN-KNAW), 1105 BA Amsterdam, The Netherlands
- Correspondence:
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15
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Defining Phenotype, Tropism, and Retinal Gene Therapy Using Adeno-Associated Viral Vectors (AAVs) in New-Born Brown Norway Rats with a Spontaneous Mutation in Crb1. Int J Mol Sci 2021; 22:ijms22073563. [PMID: 33808129 PMCID: PMC8036486 DOI: 10.3390/ijms22073563] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 12/26/2022] Open
Abstract
Mutations in the Crumbs homologue 1 (CRB1) gene cause inherited retinal dystrophies, such as early-onset retinitis pigmentosa and Leber congenital amaurosis. A Brown Norway rat strain was reported with a spontaneous insertion-deletion (indel) mutation in exon 6 of Crb1. It has been reported that these Crb1 mutant rats show vascular abnormalities associated with retinal telangiectasia and possess an early-onset retinal degenerative phenotype with outer limiting membrane breaks and focal loss of retinal lamination at 2 months of age. Here, we further characterized the morphological phenotype of new-born and adult Crb1 mutant rats in comparison with age-matched Brown Norway rats without a mutation in Crb1. A significantly decreased retinal function and visual acuity was observed in Crb1 mutant rats at 1 and 3 months of age, respectively. Moreover, in control rats, the subcellular localization of canonical CRB1 was observed at the subapical region in Müller glial cells while CRB2 was observed at the subapical region in both photoreceptors and Müller glial cells by immuno-electron microscopy. CRB1 localization was lost in the Crb1 mutant rats, whereas CRB2 was still observed. In addition, we determined the tropism of subretinal or intravitreally administered AAV5-, AAV9- or AAV6-variant ShH10Y445F vectors in new-born control and Crb1 mutant rat retinas. We showed that subretinal injection of AAV5 and AAV9 at postnatal days 5 (P5) or 8 (P8) predominantly infected the retinal pigment epithelium (RPE) and photoreceptor cells; while intravitreal injection of ShH10Y445F at P5 or P8 resulted in efficient infection of mainly Müller glial cells. Using knowledge of the subcellular localization of CRB1 and the ability of ShH10Y445F to infect Müller glial cells, canonical hCRB1 and hCRB2 AAV-mediated gene therapy were explored in new-born Crb1 mutant rats. Enhanced retinal function after gene therapy delivery in the Crb1 rat was not observed. No timely rescue of the retinal phenotype was observed using retinal function and visual acuity, suggesting the need for earlier onset of expression of recombinant hCRB proteins in Müller glial cells to rescue the severe retinal phenotype in Crb1 mutant rats.
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16
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Retinal Neurodegeneration: Correlation between Nutraceutical Treatment and Animal Model. Nutrients 2021; 13:nu13030770. [PMID: 33673449 PMCID: PMC7997156 DOI: 10.3390/nu13030770] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/20/2021] [Accepted: 02/24/2021] [Indexed: 12/14/2022] Open
Abstract
Retinal diseases can be induced by a variety of factors, including gene mutations, environmental stresses and dysmetabolic processes. The result is a progressive deterioration of visual function, which sometimes leads to blindness. Many treatments are under investigation, though results are still mostly unsatisfactory and restricted to specific pathologies, particularly in the case of gene therapy. The majority of treatments have been tested in animal models, but very few have progressed to human clinical trials. A relevant approach is to study the relation between the type of treatments and the degenerative characteristics of the animal model to better understand the effectiveness of each therapy. Here we compare the results obtained from different animal models treated with natural compounds (saffron and naringenin) to anticipate the potentiality of a single treatment in different pathologies.
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17
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Cell therapy with hiPSC-derived RPE cells and RPCs prevents visual function loss in a rat model of retinal degeneration. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 20:688-702. [PMID: 33738324 PMCID: PMC7937540 DOI: 10.1016/j.omtm.2021.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 02/04/2021] [Indexed: 12/18/2022]
Abstract
Photoreceptor loss is the principal cause of blindness in retinal degenerative diseases (RDDs). Whereas some therapies exist for early stages of RDDs, no effective treatment is currently available for later stages, and once photoreceptors are lost, the only option to rescue vision is cell transplantation. With the use of the Royal College of Surgeons (RCS) rat model of retinal degeneration, we sought to determine whether combined transplantation of human-induced pluripotent stem cell (hiPSC)-derived retinal precursor cells (RPCs) and retinal pigment epithelial (RPE) cells was superior to RPE or RPC transplantation alone in preserving retinal from degeneration. hiPSC-derived RPCs and RPE cells expressing (GFP) were transplanted into the subretinal space of rats. In vivo monitoring showed that grafted cells survived 12 weeks in the subretinal space, and rats treated with RPE + RPC therapy exhibited better conservation of the outer nuclear layer (ONL) and visual response than RPE-treated or RPC-treated rats. Transplanted RPE cells integrated in the host RPE layer, whereas RPC mostly remained in the subretinal space, although a limited number of cells integrated in the ONL. In conclusion, the combined transplantation of hiPSC-derived RPE and RPCs is a potentially superior therapeutic approach to protect retina from degeneration in RDDs.
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18
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Greferath U, Huynh M, Jobling AI, Vessey KA, Venables G, Surrao D, O'Neill HC, Limnios IJ, Fletcher EL. Dorsal-Ventral Differences in Retinal Structure in the Pigmented Royal College of Surgeons Model of Retinal Degeneration. Front Cell Neurosci 2021; 14:553708. [PMID: 33536874 PMCID: PMC7848141 DOI: 10.3389/fncel.2020.553708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 12/17/2020] [Indexed: 11/29/2022] Open
Abstract
Retinitis pigmentosa is a family of inherited retinal degenerations associated with gradual loss of photoreceptors, that ultimately leads to irreversible vision loss. The Royal College of Surgeon's (RCS) rat carries a recessive mutation affecting mer proto-oncogene tyrosine kinase (merTK), that models autosomal recessive disease. The aim of this study was to understand the glial, microglial, and photoreceptor changes that occur in different retinal locations with advancing disease. Pigmented RCS rats (RCS-p+/LAV) and age-matched isogenic control rdy (RCS-rdy +p+/LAV) rats aged postnatal day 18 to 6 months were evaluated for in vivo retinal structure and function using optical coherence tomography and electroretinography. Retinal tissues were assessed using high resolution immunohistochemistry to evaluate changes in photoreceptors, glia and microglia in the dorsal, and ventral retina. Photoreceptor dysfunction and death occurred from 1 month of age. There was a striking difference in loss of photoreceptors between the dorsal and ventral retina, with a greater number of photoreceptors surviving in the dorsal retina, despite being adjacent a layer of photoreceptor debris within the subretinal space. Loss of photoreceptors in the ventral retina was associated with fragmentation of the outer limiting membrane, extension of glial processes into the subretinal space that was accompanied by possible adhesion and migration of mononuclear phagocytes in the subretinal space. Overall, these findings highlight that breakdown of the outer limiting membrane could play an important role in exacerbating photoreceptor loss in the ventral retina. Our results also highlight the value of using the RCS rat to model sectorial retinitis pigmentosa, a disease known to predominantly effect the inferior retina.
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Affiliation(s)
- Una Greferath
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Mario Huynh
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Andrew Ian Jobling
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Kirstan Anne Vessey
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Gene Venables
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Denver Surrao
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, Australia
| | - Helen Christine O'Neill
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, Australia
| | - Ioannis J Limnios
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, Australia
| | - Erica Lucy Fletcher
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
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Tan B, Barathi VA, Lin E, Ho C, Gan A, Yao X, Chan A, Wong DWK, Chua J, Tan GS, Schmetterer L. Longitudinal Structural and Microvascular Observation in RCS Rat Eyes Using Optical Coherence Tomography Angiography. Invest Ophthalmol Vis Sci 2021; 61:54. [PMID: 32579681 PMCID: PMC7415900 DOI: 10.1167/iovs.61.6.54] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the change of retinal thickness and ocular microvasculature in a rat model of retinitis pigmentosa using swept source optical coherence tomography angiography (SS-OCTA) Methods Three-weeks-old Royal College of Surgeons (RCS) rats (n = 8) and age-matched control rats (n = 14) were imaged by a prototype SS-OCTA system. Follow-up measurements occurred every three weeks on six RCS rats until week 18, and cross-sectional measurements were conducted on control rats. Thicknesses of different retinal layers and the total retina were measured. The enface angiograms from superficial vascular plexiform (SVP) and deep capillary plexiform (DCP) were analyzed, and the image sharpness was also extracted from the choroidal angiograms. Immunohistochemical analysis was done in the RCS rats after week 18, as well as in three-week-old RCS rats and age-matched controls. Results In RCS rats, the thicknesses of the ganglion cell complex, the nuclear layer, the debris/photoreceptor layer and the total retina decreased over the weeks (P < 0.001). The SVP metrics remained unchanged whereas the DCP metrics decreased significantly over the weeks (P < 0.001). The immunohistochemical analysis confirmed our OCTA findings of capillary dropout in the DCP. The choroidal plexus appeared indistinct initially due to scattering of light at the intact retinal pigment epithelium (RPE) and became more visible after week nine probably due to RPE degeneration. Loss of choriocapillaris was visualized at week 18. In control rats, no vascular change was detected, but nuclear layers, photoreceptor layers and total retina showed slight thinning with age (P < 0.001). Conclusions Photoreceptor degeneration in RCS rats was associated with the loss of capillaries in DCP, but not in SVP. The OCTA imaging allows for the characterization of structural and angiographic changes in rodent models.
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20
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Sher I, Moverman D, Ketter-Katz H, Moisseiev E, Rotenstreich Y. In vivo retinal imaging in translational regenerative research. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1096. [PMID: 33145315 PMCID: PMC7575995 DOI: 10.21037/atm-20-4355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Regenerative translational studies must include a longitudinal assessment of the changes in retinal structure and function that occur as part of the natural history of the disease and those that result from the studied intervention. Traditionally, retinal structural changes have been evaluated by histological analysis which necessitates sacrificing the animals. In this review, we describe key imaging approaches such as fundus imaging, optical coherence tomography (OCT), OCT-angiography, adaptive optics (AO), and confocal scanning laser ophthalmoscopy (cSLO) that enable noninvasive, non-contact, and fast in vivo imaging of the posterior segment. These imaging technologies substantially reduce the number of animals needed and enable progression analysis and longitudinal follow-up in individual animals for accurate assessment of disease natural history, effects of interventions and acute changes. We also describe the benefits and limitations of each technology, as well as outline possible future directions that can be taken in translational retinal imaging studies.
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Affiliation(s)
- Ifat Sher
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Moverman
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Hadas Ketter-Katz
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elad Moisseiev
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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21
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Patil MA, Kompella UB. Noninvasive Monitoring of Choroid-Retina Autofluorescence and Intravitreal Nanoparticle Disposition in Royal College of Surgeon Rats of Different Ages and Retinal Thinning. J Ocul Pharmacol Ther 2020; 36:458-466. [PMID: 32552217 DOI: 10.1089/jop.2020.0028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: To determine the baseline choroid-retina fluorescence signal in Royal College of Surgeon (RCS) rats of various ages with different degrees of retinal degeneration and assess the persistence of intravitreal nanoparticles. Methods: In RCS rats of age 6, 12, and 20 weeks and Sprague Dawley (SD) rats of age 6 and 20 weeks, baseline eye tissue fluorescence and retinal thickness were recorded noninvasively using fluorophotometry and optical coherence tomography (OCT), respectively. Further, 20-nm carboxylate-modified fluorescent particles were injected intravitreally in the above groups of rats, and the depth-wise fluorescence signal was monitored over 7 days using fluorophotometry and confocal laser scanning ophthalmoscopy (cSLO). Additionally, 200 nm particles of the same material were injected intravitreally into about 7-week-old RCS rats and the fluorescence signal was monitored up to 35 days using fluorophotometry. Results: Reduction in retinal thickness and an increase in choroid-retina and lens baseline fluorescence was observed with increasing age of RCS and SD rats. The 20 nm particles persisted in the vitreous of animals from all age groups for at least 7 days postadministration, irrespective of the differences in retinal thickness. cSLO confirmed nanoparticle persistence in the eye. The fluorescence signal from 200 nm particles persisted for 35 days in the vitreous humor. Conclusions: Choroid-retina and lens autofluorescence monitored using fluorophotometry increase with age. Intravitreally injected nanoparticles can be monitored noninvasively in rats using fluorophotometry and cSLO imaging. Both 20 and 200 nm particles persist in the back of the eye tissues, for several days following intravitreal injection.
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Affiliation(s)
- Madhoosudan A Patil
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Uday B Kompella
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Department of Bioengineering, and University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Department of Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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The qualitative assessment of optical coherence tomography and the central retinal sensitivity in patients with retinitis pigmentosa. PLoS One 2020; 15:e0232700. [PMID: 32392207 PMCID: PMC7213731 DOI: 10.1371/journal.pone.0232700] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 04/19/2020] [Indexed: 12/16/2022] Open
Abstract
Purpose To analyze the relationships between qualitative and quantitative parameters of spectral-domain optical coherence tomography (SD-OCT) and the central retinal sensitivity in patients with retinitis pigmentosa (RP). Materials and methods Ninety-three eyes of 93 patients were finally enrolled, with a median age (quartile) of 58 (24.5) years. We assessed the patients using SD-OCT and the 10–2 program of a Humphry Field Analyzer (HFA). As a qualitative parameter, two graders independently classified the patients’ SD-OCT images into five severity grades (grades 1–5) based on the severity of damage to the photoreceptor inner and outer segments (IS/OS) layer. As quantitative parameters, we measured the IS-ellipsoid zone (IS-EZ) width, IS/OS thickness, outer nuclear layer (ONL) thickness, central macular thickness (CMT, 1 and 3 mm) and macular cube (6 × 6 mm) volume and thickness. The central retinal sensitivity was defined by the best-corrected visual acuity (BCVA; logMAR), average sensitivities of the central 4 (foveal sensitivity [FS]) and 12 (macular sensitivity [MS]) points of the HFA 10–2 program and the mean deviation (MD) of the 10–2 program. Spearman’s correlation was used to assess the association between both qualitative and quantitative parameters and variables of the central retinal sensitivity. In addition, we performed a multiple regression analysis using these parameters to identify the parameters most strongly influencing the central retinal sensitivity. Results The IS/OS severity grade was significantly correlated with the BCVA (ρ = 0.741, P < 0.001), FS (ρ = −0.844, P < 0.001), MS (ρ = −0.820, P < 0.001) and MD (ρ = −0.681, P < 0.001) and showed stronger correlations to them than any other quantitative parameters including the IS-EZ width, IS/OS thickness, ONL thickness, CMTs and macular cube volume/thickness. Furthermore, a step-wise multiple regression analysis indicated that the IS/OS severity grade was more strongly associated with the BCVA (β = 0.659, P < 0.001), FS (β = −0.820, P < 0.001), MS (β = −0.820, P < 0.001) and MD (β = −0.674, P < 0.001) than any other quantitative parameters. The intraclass correlation coefficient between two graders indicated substantial correlation (κ = 0.70). Discussion The qualitative grading of OCT based on the severity of the IS/OS layer was simple and strongly correlated with the central retinal sensitivity in patients with RP. It may be useful to assess the central visual function in patients with RP, although there is some variation in severity within the same severity grade.
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A spectral-domain optical coherence tomographic analysis of Rdh5-/- mice retina. PLoS One 2020; 15:e0231220. [PMID: 32271812 PMCID: PMC7144952 DOI: 10.1371/journal.pone.0231220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/18/2020] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To investigate the longitudinal findings of spectral-domain optical coherence tomography (SD-OCT) in relation to the morphologic features in Rdh5 knockout (Rdh5-/-) mice. MATERIALS AND METHODS The mouse retina was segmented into four layers; the inner retinal (A), outer plexiform and outer nuclear (B), rod/cone (C), and retinal pigment epithelium (RPE)/choroid (D) layers. The thickness of each retinal layer of Rdh5-/- mice was longitudinally and quantitatively measured at six time points from postnatal months (PM) 1 to PM6 using SD-OCT. Age-matched C57BL/6J mice were employed as wild-type controls. The data were statistically compared using Student's t-test. The fundus appearance was assessed, histologic and ultrastructural examinations were performed in both groups. RESULTS Layers A and B were significantly thinner in the Rdh5-/- mice than in the wild-type C57BL/6J mice during the observation periods. Layers C and D became thinner in the Rdh5-/- mice than in the wild-type mice after PM6. Although no abnormalities corresponding to whitish fundus dots were detected by SD-OCT or histologic examinations, the intracellular accumulation of low-density vacuoles was noted in the RPE of the Rdh5-/- mice by electron microscopy. The photoreceptor nuclei appeared less dense in the Rdh5-/- mice than in the wild-type mice. DISCUSSION The results from the present study suggest that although it is difficult to detect qualitative abnormalities, SD-OCT can detect quantitative changes in photoreceptors even in the early stage of retinal degeneration induced by the Rdh5 gene mutation in mice.
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Liu YF, Huang S, Ng TK, Liang JJ, Xu Y, Chen SL, Xu C, Zhang M, Pang CP, Cen LP. Longitudinal evaluation of immediate inflammatory responses after intravitreal AAV2 injection in rats by optical coherence tomography. Exp Eye Res 2020; 193:107955. [PMID: 32017940 DOI: 10.1016/j.exer.2020.107955] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 02/05/2023]
Abstract
Gene therapy has been proposed as a feasible strategy for RGC survival and optic nerve regeneration. Some preclinical and clinical studies revealed intraocular inflammation after intravitreal injection of adeno-associated virus (AAV) by slit-lamp or indirect ophthalmoscope. Here we evaluate the longitudinal profile of immediate inflammatory responses after AAV2 injection in rat retina and vitreous body by optical coherence tomography (OCT). Adult Fischer F344 rats were intravitreally injected once with saline, AAV2 or zymosan. Retinal thickness and cell infiltration were recorded by OCT longitudinally for 2 months and verified by histological analysis. The transduction rate of single intravitreal AAV2 injection was 21.3 ± 4.9% of whole retina, and the transduction efficiency on RGCs was 91.5 ± 2.5% in the transduced area. Significant increase in cell infiltration was observed from Day 1-3 after AAV2 injection, compared to very few infiltrating cells observed in the saline-injected group. The infiltrating cells ceased at Day 5 after intravitreal injection and remained absent at 2 months. The thicknesses of total and inner retina were increased along Day 1-3 after AAV2 injection, but reverted to normal afterwards. The surviving RGCs in the AAV2-injected groups at Day 14 showed no significant difference compared to saline-injected group. In summary, this study revealed the immediate inflammatory responses and retinal edema after intravitreal AAV2 injection in normal rats, without influencing long-term retinal thickness and RGC survival. OCT can be implemented for the time-lapse in vivo evaluation of inflammatory response after AAV-mediated gene therapy through intravitreal injection.
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Affiliation(s)
- Yu-Fen Liu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China
| | - Shaofen Huang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jia-Jian Liang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Shao-Lang Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Ciyan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Mingzhi Zhang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Chi Pui Pang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Ling-Ping Cen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China.
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Tong W, Meffin H, Garrett DJ, Ibbotson MR. Stimulation Strategies for Improving the Resolution of Retinal Prostheses. Front Neurosci 2020; 14:262. [PMID: 32292328 PMCID: PMC7135883 DOI: 10.3389/fnins.2020.00262] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/09/2020] [Indexed: 12/17/2022] Open
Abstract
Electrical stimulation using implantable devices with arrays of stimulating electrodes is an emerging therapy for neurological diseases. The performance of these devices depends greatly on their ability to activate populations of neurons with high spatiotemporal resolution. To study electrical stimulation of populations of neurons, retina serves as a useful model because the neural network is arranged in a planar array that is easy to access. Moreover, retinal prostheses are under development to restore vision by replacing the function of damaged light sensitive photoreceptors, which makes retinal research directly relevant for curing blindness. Here we provide a progress review on stimulation strategies developed in recent years to improve the resolution of electrical stimulation in retinal prostheses. We focus on studies performed with explanted retinas, in which electrophysiological techniques are the most advanced. We summarize achievements in improving the spatial and temporal resolution of electrical stimulation of the retina and methods to selectively stimulate neurons with different visual functions. Future directions for retinal prostheses development are also discussed, which could provide insights for other types of neuromodulatory devices in which high-resolution electrical stimulation is required.
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Affiliation(s)
- Wei Tong
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
- School of Physics, The University of Melbourne, Melbourne, VIC, Australia
| | - Hamish Meffin
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC, Australia
| | - David J. Garrett
- School of Physics, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael R. Ibbotson
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
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Cuenca N, Ortuño-Lizarán I, Sánchez-Sáez X, Kutsyr O, Albertos-Arranz H, Fernández-Sánchez L, Martínez-Gil N, Noailles A, López-Garrido JA, López-Gálvez M, Lax P, Maneu V, Pinilla I. Interpretation of OCT and OCTA images from a histological approach: Clinical and experimental implications. Prog Retin Eye Res 2020; 77:100828. [PMID: 31911236 DOI: 10.1016/j.preteyeres.2019.100828] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/16/2019] [Accepted: 12/30/2019] [Indexed: 12/17/2022]
Abstract
Optical coherence tomography (OCT) and OCT angiography (OCTA) have been a technological breakthrough in the diagnosis, treatment, and follow-up of many retinal diseases, thanks to its resolution and its ability to inform of the retinal state in seconds, which gives relevant information about retinal degeneration. In this review, we present an immunohistochemical description of the human and mice retina and we correlate it with the OCT bands in health and pathological conditions. Here, we propose an interpretation of the four outer hyperreflective OCT bands with a correspondence to retinal histology: the first and innermost band as the external limiting membrane (ELM), the second band as the cone ellipsoid zone (EZ), the third band as the outer segment tips phagocytosed by the pigment epithelium (PhaZ), and the fourth band as the mitochondria in the basal portion of the RPE (RPEmitZ). The integrity of these bands would reflect the health of photoreceptors and retinal pigment epithelium. Moreover, we describe how the vascular plexuses vary in different regions of the healthy human and mice retina, using OCTA and immunohistochemistry. In humans, four, three, two or one plexuses can be observed depending on the distance from the fovea. Also, specific structures such as vascular loops in the intermediate capillary plexus, or spider-like structures of interconnected capillaries in the deep capillary plexus are found. In mice, three vascular plexuses occupy the whole retina, except in the most peripheral retina where only two plexuses are found. These morphological issues should be considered when assessing a pathology, as some retinal diseases are associated with structural changes in blood vessels. Therefore, the analysis of OCT bands and OCTA vascular plexuses may be complementary for the diagnosis and prognosis of retinal degenerative processes, useful to assess therapeutic approaches, and it is usually correlated to visual acuity.
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Affiliation(s)
- Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain; Institute Ramón Margalef, University of Alicante, Alicante, Spain.
| | | | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain
| | - Oksana Kutsyr
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain
| | | | | | - Natalia Martínez-Gil
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain
| | - Agustina Noailles
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain
| | | | | | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa, University Hospital, Zaragoza, Spain
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27
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Tong W, Stamp M, Apollo NV, Ganesan K, Meffin H, Prawer S, Garrett DJ, Ibbotson MR. Improved visual acuity using a retinal implant and an optimized stimulation strategy. J Neural Eng 2019; 17:016018. [DOI: 10.1088/1741-2552/ab5299] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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28
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Valiente-Soriano FJ, Ortín-Martínez A, Di Pierdomenico J, García-Ayuso D, Gallego-Ortega A, Miralles de Imperial-Ollero JA, Jiménez-López M, Villegas-Pérez MP, Wheeler LA, Vidal-Sanz M. Topical Brimonidine or Intravitreal BDNF, CNTF, or bFGF Protect Cones Against Phototoxicity. Transl Vis Sci Technol 2019; 8:36. [PMID: 31890348 PMCID: PMC6919195 DOI: 10.1167/tvst.8.6.36] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/07/2019] [Indexed: 01/20/2023] Open
Abstract
Purpose To develop a focal photoreceptor degeneration model by blue light-emitting diode (LED)-induced phototoxicity (LIP) and investigate the protective effects of topical brimonidine (BMD) or intravitreal brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), or basic fibroblast growth factor (bFGF). Methods In anesthetized, dark-adapted, adult female Swiss mice, the left eye was dilated and exposed to blue light (10 seconds, 200 lux). After LIP, full-field electroretinograms (ERG) and spectral-domain optical coherence tomography (SD-OCT) were obtained longitudinally, and reactive-Iba-1+monocytic cells, TUNEL+ cells and S-opsin+ cone outer segments were examined up to 7 days. Left eyes were treated topically with BMD (1%) or vehicle, before or right after LIP, or intravitreally with BDNF (2.5 μg), CNTF (0.2 μg), bFGF (0.5 μg), or corresponding vehicle right after LIP. At 7 days, S-opsin+ cone outer segments were counted within predetermined fixed-size areas (PFA) centered on the lesion in both flattened retinas. Results SD-OCT showed a circular region in the superior-temporal left retina with progressive thinning (207.9 ± 5.6 μm to 160.7 ± 6.8 μm [7 days], n = 8), increasing TUNEL+ cells (peak at 3 days), decreasing S-opsin+ cone outer segments, and strong microglia activation. ERGs were normal by 3 days. Total S-opsin+ cones in the PFA for LIP-treated and fellow-retinas were 2330 ± 262 and 5601 ± 583 (n = 8), respectively. All neuroprotectants (n = 7–11), including topical BMD pre- or post-LIP, or intravitreal BDNF, CNTF, and bFGF, showed significantly greater S-opsin+ cone survival than their corresponding vehicle-treated groups. Conclusions LIP is a reliable, quantifiable focal photoreceptor degeneration model. Topical BMD or intravitreal BDNF, CNTF, or bFGF protect against LIP-induced cone-photoreceptor loss. Translational Relevance Topical BMD or intravitreal BDNF, CNTF, or bFGF protect cones against phototoxicity.
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Affiliation(s)
- Francisco J Valiente-Soriano
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Arturo Ortín-Martínez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Present Address: Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Johnny Di Pierdomenico
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Diego García-Ayuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Alejandro Gallego-Ortega
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Juan A Miralles de Imperial-Ollero
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Manuel Jiménez-López
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - María Paz Villegas-Pérez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Larry A Wheeler
- Ophthalmology and Visual Science, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
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Optical Coherence Tomography of Animal Models of Retinitis Pigmentosa: From Animal Studies to Clinical Applications. BIOMED RESEARCH INTERNATIONAL 2019; 2019:8276140. [PMID: 31781647 PMCID: PMC6875330 DOI: 10.1155/2019/8276140] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 09/18/2019] [Indexed: 11/17/2022]
Abstract
Purpose The aim of this study was to understand the relationship between the findings of spectral-domain optical coherence tomography (SD-OCT) of previously reported animal models of retinitis pigmentosa (RP) associated with known genetic mutations and their background structural and functional changes. Methods We reviewed previous publications reporting the SD-OCT findings of animal models of RP and summarized the characteristic findings of SD-OCT in nine different animal models (RCS -/- , RHO P23H, RHO S334ter, RHO -/- , Rpe65 -/- , rp12, Pde6β -/- (rd1 and rd10), and Arr1 -/- ) of human RP. Results Despite the various abnormal structural changes found in these different animal models, progressive thinning of the outer nuclear layer (ONL) and hyperreflective change in the inner and outer segment (IS-OS) layers of the photoreceptors were commonly observed on SD-OCT. In the rapidly progressive severe photoreceptor degeneration seen in rd10 and Arr1 -/- mice, the ONL appeared hyperreflective. Electroretinography revealed various degrees of disease severity in these animal models. Discussion and Conclusion: SD-OCT is sensitive enough to detect even mild changes in the photoreceptor OS. Conversely, SD-OCT cannot qualitatively differentiate the pathologic and functional differences in the photoreceptors associated with different genetic abnormalities, with the exception of the rapid progression of severe forms of photoreceptor degeneration. These findings can be of value to understand better the clinical findings and the heterogeneous degenerative processes in patients with RP.
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Chintalapudi SR, Wang X, Wang X, Shi Y, Kocak M, Palamoor M, Davis RN, Hollingsworth TJ, Jablonski MM. NA3 glycan: a potential therapy for retinal pigment epithelial deficiency. FEBS J 2019; 286:4876-4888. [PMID: 31322324 DOI: 10.1111/febs.15006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 05/07/2019] [Accepted: 07/16/2019] [Indexed: 12/01/2022]
Abstract
Atrophic age-related macular degeneration (AMD) is the most common type of AMD, yet there is no United States Food and Drug Administration (FDA)-approved therapy. This disease is characterized by retinal pigment epithelial (RPE) insufficiency, primarily in the macula, which affects the structure and physiology of photoreceptors and ultimately, visual function. In this study, we evaluated the protective effects of a naturally derived small molecule glycan therapeutic-asialo-, tri-antennary complex-type N-glycan (NA3)-in two distinct preclinical models of atrophic AMD. In RPE-deprived Xenopus laevis tadpole eyes, NA3 supported normal retinal ultrastructure. In RCS rats, NA3 supported fully functioning visual integrity. Furthermore, structural analyses revealed that NA3 prevented photoreceptor outer segment degeneration, pyknosis of the outer nuclear layer, and reactive gliosis of Müller cells (MCs). It also promoted maturation of adherens junctions between MC and photoreceptors. Our results demonstrate the neuroprotective effects of a naturally derived small molecular glycan therapeutic-NA3-in two unique preclinical models with RPE insufficiency. These data suggest that NA3 glycan therapy may provide a new therapeutic avenue in the prevention and/or treatment of retinal diseases such as atrophic AMD.
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Affiliation(s)
- Sumana R Chintalapudi
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - XiangDi Wang
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - XiaoFei Wang
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Yunfeng Shi
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Mehmet Kocak
- Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Mallika Palamoor
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Raven N Davis
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - T J Hollingsworth
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Monica M Jablonski
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
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31
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Bubis E, Sher I, Skaat A, Sharvit-Ginon I, Szalapak AM, Moroz I, Kalter-Leibovici O, Rotenstreich Y. Blue Autofluorescence Fundus Imaging for Monitoring Retinal Degeneration in Royal College of Surgeons Rats. Transl Vis Sci Technol 2019; 8:26. [PMID: 30834174 PMCID: PMC6396687 DOI: 10.1167/tvst.8.1.26] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 12/16/2018] [Indexed: 02/03/2023] Open
Abstract
Purpose Development of a method for noninvasive longitudinal follow-up of retinal degeneration in the whole retina for Royal College of Surgeons (RCS) rats, a commonly used model of retinitis pigmentosa associated with mutations in the MER-proto-oncogene tyrosine kinase (MERTK) gene. Methods Pigmented RCS rats at postnatal (p) days p28 to p84 were subjected to a biweekly spectral-domain optical coherence tomography (SD-OCT), blue laser fundus autofluorescence (BL-FAF) imaging, and multicolor fundus imaging. Wild-type (WT; Long Evans) rats were tested as control. Results Hyperautofluorescence developed throughout the fundus at p42, concomitant with a significant increase in SD-OCT thickness and reflectivity of the debris zone (DZ) layer as well as thinning of the photoreceptor outer nuclear layer (ONL). From p56 to p84, discrete hypofluorescent lesions surrounded by hyperfluorescent flecks were demonstrated around the optic disc that gradually spread throughout the retina. The hypofluorescent lesions were associated with loss of ONL and gradual thinning of the DZ layer. No hypofluorescent BL-FAF lesions were observed in WT rats. Conclusions This study suggests that BL-FAF imaging may present a new method for noninvasive longitudinal follow-up of retinal degeneration in nearly the whole retina in RCS rats. Translational Relevance A clinical test was developed that may be implemented in translational studies in the RCS rat model of MERTK-associated retinitis pigmentosa.
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Affiliation(s)
- Ettel Bubis
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ifat Sher
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Alon Skaat
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Inbal Sharvit-Ginon
- Department of Psychology, Bar Ilan University, Ramat-Gan, Israel.,The Joseph Sagol Neuroscience Center at Sheba Medical Center, Israel
| | | | - Iris Moroz
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ofra Kalter-Leibovici
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Unit of Cardiovascular Epidemiology, Gertner Institute for Epidemiology and Health Policy Research, Ramat Gan, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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32
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Tanabu R, Sato K, Monai N, Yamauchi K, Gonome T, Xie Y, Takahashi S, Ishiguro SI, Nakazawa M. The findings of optical coherence tomography of retinal degeneration in relation to the morphological and electroretinographic features in RPE65-/- mice. PLoS One 2019; 14:e0210439. [PMID: 30695025 PMCID: PMC6350961 DOI: 10.1371/journal.pone.0210439] [Citation(s) in RCA: 15] [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: 06/06/2018] [Accepted: 12/21/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose Mutations of the gene encoding RPE65 cause Leber congenital amaurosis (LCA) retinitis pigmentosa (RP). The optical coherence tomography (OCT) is increasingly utilized to noninvasively evaluate various types of retinal diseases, including RP. The present study was conducted to characterize the OCT findings of the RPE65−/− mice—an animal model of LCA and RP—in relation to the morphological features based on histological and electron microscopic findings as well as electroretinography (ERG) features. Materials and methods RPE65−/− mice were employed as a model of retinal degeneration. C57BL/6J mice were used as a wild-type control. OCT was performed on the RPE65−/− mice from postnatal day (P) 22 to 170. The longitudinal changes in the OCT images and fundus pictures were analyzed both qualitatively and quantitatively in comparison to those of C57BL/6J mice. The OCT images were also compared to the histological and electron microscopic findings. Full field combined rod and cone ERG was performed to analyze the relationship between morphology based on OCT and the amplitudes of the a- and b-waves. Results In the RPE65−/− mice, the photoreceptor rod and cone layer appeared as a diffuse hyperreflective zone contiguous with the inner segment ellipsoid zone (IS-EZ) on OCT, even on P22, whereas the IS-EZ and interdigitation zone were clearly identified in the age-matched C57BL/6J mice. The histological analyses revealed that the regular arrangement of the photoreceptor inner and outer segments was gradually lost in the RPE65-/- mice. On electron microscopy, most of the rod outer segments were degenerated from P21 to P35, whereas outer segments became variably shorter after P49 although ultrastructure appeared to normalize. The thickness of the outer nuclear layer of RPE65−/− mice was slowly and progressively reduced in comparison to C57BL/6J mice. Although the thickness of the inner and outer segment layer of RPE65−/− mice was significantly decreased in comparison to C57BL/6J mice, the change was not progressive, at least until P170. Even at P35, the amplitudes of both a- and b-waves on ERG were severely deteriorated in comparison to those of C57BL/6J mice. Mottled depigmented spots appeared throughout the fundus in RPE65−/− mice after P72, and were detected as hyperreflective deposits under the retinal pigment epithelium on OCT. Discussion The pathological changes in the inner and outer segments layer of RPE65−/− mice were identified as diffuse hyperreflective changes on OCT. The rod outer segments showed degeneration in the early postnatal periods but became morphologically normalized in the disc structure after P49, although the sizes of the length of the rod outer segments were variable. OCT could not qualitatively differentiate the early degeneration of rods from the late variability in size of rods. Although the morphology of the photoreceptor outer segments was relatively preserved in the RPE65−/− mice, the amplitudes of ERG were severely disturbed. These structural and functional deficits may be derived from the defective supply of 11-cis-retinol to the photoreceptors.
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Affiliation(s)
- Reiko Tanabu
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kota Sato
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Natsuki Monai
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kodai Yamauchi
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Takayuki Gonome
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Yuting Xie
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Shizuka Takahashi
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Sei-ichi Ishiguro
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mitsuru Nakazawa
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
- * E-mail:
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Noninvasive Diagnosis of Regional Alteration of Retinal Morphology and Structure with Optical Coherence Tomography in Rodents. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:151-155. [PMID: 31884604 DOI: 10.1007/978-3-030-27378-1_25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Spectral-domain optical coherence tomography (SD-OCT) produces high-resolution images of retinal cross sections and is becoming a method of choice for in vivo analyses of retinal morphology in rodents. We have adopted this technology to identify and analyze alterations of retinal structure, particularly those with regional and subtle changes. In this technical brief, we will demonstrate the use of SD-OCT in identifying subtle changes in retinal structure and morphology due to the effect of mosaic gene deletion in conditional knockout mice and of uneven distribution of intravitreally delivered compounds, review the application of SD-OCT in measuring pathological lesion volumes, and discuss the major benefits of SD-OCT technology over the traditional histological methods.
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Murali A, Ramlogan-Steel CA, Andrzejewski S, Steel JC, Layton CJ. Retinal explant culture: A platform to investigate human neuro-retina. Clin Exp Ophthalmol 2018; 47:274-285. [PMID: 30378239 DOI: 10.1111/ceo.13434] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/01/2018] [Accepted: 10/22/2018] [Indexed: 01/09/2023]
Abstract
The retina is the tissue responsible for light detection, in which retinal neurons convert light energy into electrical signals to be transported towards the visual cortex. Damage of retinal neurons leads to neuronal cell death and retinal pathologies, compromising visual acuity and eventually leading to irreversible blindness. Models of retinal neurodegeneration include 2D systems like cell lines, disassociated cultures and co-cultures, and 3D models like organoids, organotypic retinal cultures and animal models. Of these, ex vivo human retinal cultures are arguably the most suitable models for translational research as they retain complex inter-cellular interactions of the retina and precisely mimic in-situ responses. In this review, we summarize the distinguishing features of the human retina which are important to preserve in experimental culture, the historical development of human retinal culture systems, the factors affecting ex vivo human retinal culture and the applications and challenges associated with current methods of human retinal explant culture.
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Affiliation(s)
- Aparna Murali
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Charmaine A Ramlogan-Steel
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia.,School of Health, Medical and Applied Sciences, CQUniversity, North Rockhampton, Queensland, Australia
| | - Slawomir Andrzejewski
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Jason C Steel
- School of Health, Medical and Applied Sciences, CQUniversity, North Rockhampton, Queensland, Australia
| | - Christopher J Layton
- LVF Ophthalmology Research Centre, Translational Research Institute, Woolloongabba, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Greenslopes Hospital, Brisbane, Queensland, Australia
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Syu JP, Buddhakosai W, Chen SJ, Ke CC, Chiou SH, Kuo WC. Supercontinuum source-based multi-contrast optical coherence tomography for rat retina imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:6132-6144. [PMID: 31065418 PMCID: PMC6490977 DOI: 10.1364/boe.9.006132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/29/2018] [Accepted: 11/01/2018] [Indexed: 05/06/2023]
Abstract
This study proposed an ultrahigh-resolution multi-contrast optical coherence tomography system integrated with fundus photography for in vivo retinal imaging of rodents. A supercontinuum light source was used in the system, providing an axial resolution of less than 3 µm within 1.8 mm (in the tissue). Three types of tissue contrast based on backscattered intensity, phase retardation, and microvasculature at a capillary level can be simultaneously obtained using the proposed system. Pigmented Long-Evans, non-pigmented (albino) Sprague Dawley, and Royal College of Surgeons rats were imaged and compared. In vivo imaging results were validated with histology.
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Affiliation(s)
- Jia-Pu Syu
- Institute of Biophotonics, National Yang-Ming University, Taipei 112, Taiwan
| | - Waradee Buddhakosai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taiwan
- School of Medicine, National Yang-Ming University, Taiwan
| | - Chang-Chih Ke
- Department and Institute of Pharmacology, National Yang-Ming University, Taipei 112, Taiwan
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taiwan
- Department and Institute of Pharmacology, National Yang-Ming University, Taipei 112, Taiwan
- Center For Intelligent Drug Systems and Smart Bio-devices (IDSB), National Chiao Tung University, Hsinchu, Taiwan
| | - Wen-Chuan Kuo
- Institute of Biophotonics, National Yang-Ming University, Taipei 112, Taiwan
- Center For Intelligent Drug Systems and Smart Bio-devices (IDSB), National Chiao Tung University, Hsinchu, Taiwan
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The Spectral-Domain Optical Coherence Tomography Findings Associated with the Morphological and Electrophysiological Changes in a Rat Model of Retinal Degeneration, Rhodopsin S334ter-4 Rats. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5174986. [PMID: 30581855 PMCID: PMC6276524 DOI: 10.1155/2018/5174986] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022]
Abstract
Purpose To characterize the spectral-domain optical coherence tomography (SD-OCT) findings of the rhodopsin S334ter transgenic rats (line 4) in relation to the morphologic and electroretinographic features. Materials and Methods Rhodopsin S334ter transgenic rats (line 4) were employed as a model of retinal degeneration. The Sprague-Dawley (SD) rats were used as a wild-type control. SD-OCT (Micron IV®; Phoenix Research Labs, Pleasanton, CA, USA) was performed on the S334ter rats (line 4) from postnatal days (P) 13−110. The longitudinal changes of the SD-OCT images were analyzed both qualitatively and quantitatively in comparison to those of SD rats. The SD-OCT images were also compared to the histological and electron microscopic findings from examination performed on P 22, 36, and 61. Full field combined rod and cone electroretinography (ERG) was performed and the relationship between the thickness of the retinal sublayers and the amplitudes of the a- and b-waves was further analyzed. Results The photoreceptor inner and outer segment layer became diffusely hyperreflective in the SD-OCT images of the S334ter rats; these findings were not observed in the SD rats. This hyperreflective change corresponded to the degenerated inner and outer segments and the accumulation of the extracellular vesicles in the interphotoreceptor matrix. Quantitatively, the retinal outer sublayer and the photoreceptor sublayer in the S334ter rats became progressively thinner in comparison to those in the SD rats; the difference was statistically significant. The amplitudes of both the a- and b-waves on ERG were severely deteriorated in the S334ter rats. Discussion The SD-OCT images in the S334ter rats noninvasively provided information regarding the pathological changes in the photoreceptors and the longitudinal changes of both qualitative and quantitative changes during retinal degeneration in the S334ter rats (line 4). The pathological features of the photoreceptor inner and outer segments can be detected on SD-OCT as diffuse hyperreflective changes in the photoreceptor layer.
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Blair NP, Tan MR, Felder AE, Teng PY, Wanek J, Shahidi M. Retinal tissue oxygen tension and consumption during light flicker stimulation in rat. Exp Eye Res 2018; 175:207-211. [PMID: 30121195 DOI: 10.1016/j.exer.2018.08.007] [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: 04/13/2018] [Revised: 08/09/2018] [Accepted: 08/12/2018] [Indexed: 10/28/2022]
Abstract
Light flicker stimulation has been shown to increase inner retinal oxygen metabolism and supply. The purpose of the study was to test the hypothesis that sustained light flicker stimulation of various durations alters the depth profile metrics of oxygen partial pressure in the retinal tissue (tPO2) but not the outer retinal oxygen consumption rate (QO2). In 17 rats, tPO2 depth profiles were derived by phosphorescence lifetime imaging after intravitreal injection of an oxyphor. tPO2 profile metrics, including mean inner retinal tPO2, maximum outer retinal tPO2 and minimum outer retinal tPO2 were determined. QO2 was calculated using a one-dimensional oxygen diffusion model. Data were acquired at baseline (constant light illumination) and during light flicker stimulation at 10 Hz under the same mean illumination levels, and differences between values obtained during flicker and baseline were calculated. None of the tPO2 profile metrics or QO2 differences depended on the duration of light flicker stimulation (R2 ≤ 0.03). No significant change in any of the tPO2 profile metrics was detected with light flicker compared with constant light (P ≥ 0.08). Light flicker decreased QO2 from 0.53 ± 0.29 to 0.38 ± 0.30 mL O2/(min*100 gm), a reduction of 28% (P = 0.02). The retinal compensatory responses to the physiologic challenge of light flicker stimulation were effective in maintaining the levels of oxygen at or near baseline in the inner retina. Oxygen availability to the inner retina during light flicker may also have been enhanced by the decrease in QO2.
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Affiliation(s)
- Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
| | - Michael R Tan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
| | - Anthony E Felder
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
| | - Pang-Yu Teng
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
| | - Justin Wanek
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
| | - Mahnaz Shahidi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL, 60612, USA.
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Selner AN, Derafshi Z, Kunzer BE, Hetling JR. Three-Dimensional Model of Electroretinogram Field Potentials in the Rat Eye. IEEE Trans Biomed Eng 2018; 65:2781-2789. [PMID: 29993425 DOI: 10.1109/tbme.2018.2816591] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The information derived from the electroretinogram (ERG), especially with regard to local areas of retinal dysfunction or therapeutic rescue, can be enhanced by an increased understanding of the relationship between local retinal current sources and local ERG potentials measured at the cornea. A critical step in this direction is the development of a robust bioelectric field model of the ERG. METHODS A finite-element model was created to simulate ERG potentials at the cornea resulting from physiologically relevant transretinal currents. A magnetic resonance image of a rat eye was segmented to define all major ocular structures, tissues were assigned conductivity values from the literature. The model was optimized to multi-electrode ERG (meERG) data recorded in healthy rat eyes, and validated with meERG data from eyes with experimental lesions in peripheral retina. RESULTS Following optimization, the simulated distribution of corneal potentials was in good agreement with measured values; residual error was comparable to the average difference of individual eyes from the measured mean. The model predicted the corneal potential distribution for eight eyes with experimental lesions with similar accuracy, and a measure of pre- to post-lesion changes in corneal potential distribution was well correlated with the location of the lesion. CONCLUSION An eye model with high anatomical accuracy was successfully validated against a robust dataset. SIGNIFICANCE This model can now be used for optimization of ERG electrode design, and to support functional mapping of the retina from meERG data via solving the inverse bioelectric source problem.
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Monai N, Yamauchi K, Tanabu R, Gonome T, Ishiguro SI, Nakazawa M. Characterization of photoreceptor degeneration in the rhodopsin P23H transgenic rat line 2 using optical coherence tomography. PLoS One 2018. [PMID: 29522537 PMCID: PMC5844545 DOI: 10.1371/journal.pone.0193778] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purpose To characterize the optical coherence tomography (OCT) appearances of photoreceptor degeneration in the rhodopsin P23H transgenic rat (line 2) in relation to the histological, ultrastructural, and electroretinography (ERG) findings. Materials and methods Homozygous rhodopsin P23H transgenic albino rats (line 2, very-slow degeneration model) were employed. Using OCT (Micron IV®; Phoenix Research Labs, Pleasanton, CA, USA), the natural course of photoreceptor degeneration was recorded from postnatal day (P) 15 to P 287. The OCT images were qualitatively observed by comparing them to histological and ultrastructural findings at P 62 and P 169. In addition, each retinal layer was quantitatively analyzed longitudinally during degeneration, compared it to that observed in wild type Sprague-Dawley (SD) rats. The relationships between the ERG (full-field combined rod-cone response, 3.0 cds/m2 stimulation) findings and OCT images were also analyzed. Results In the qualitative study, the two layers presumably corresponding to the photoreceptor inner segment ellipsoid zone (EZ) and interdigitation zone (IZ) were identified in the P23H rat until PN day 32. However, the photoreceptor inner and outer segment (IS/OS) layer became diffusely hyperreflective on OCT after P 46, and the EZ and IZ zones could no longer be identified on OCT. In contrast, in the SD rats, the EZ and IZ were clearly distinguished until at least P 247. The ultrastructural study showed partial disarrangements of the photoreceptor outer segment discs in the P23H rats at P 62, although a light-microscopic histological study detected almost no abnormality in the outer segment. In the quantitative study, the outer retinal layer including the outer plexiform layer (OPL) and the outer nuclear layer (ONL) became significantly thinner in the P23H rats than in the SD rats after P 71. The thickness of the IS/OS layer was maintained in the P23H rats until P 130, and it became statistically thinner than in the SD rats at P 237. The longitudinal attenuation in the amplitude of the a- and b-waves of ERG was significantly correlated with the thickness of the combined OPL and ONL but not with that of the IS/OS layer. Conclusion OCT showed the degenerated photoreceptor IS/OS layer in rhodopsin P23H transgenic rats (line 2) as a diffuse hyperreflective zone, even in the early stage, with the partially disarranged and destabilized OS discs recognizable by ultrastructural assessment but not by a histological study. The amplitude of the a- and b-waves mainly depends on the thickness of the OPL and ONL layer rather than the thickness of the photoreceptor IS/OS layer in P23H rats.
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Affiliation(s)
- Natsuki Monai
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kodai Yamauchi
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Reiko Tanabu
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Takayuki Gonome
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Sei-ichi Ishiguro
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mitsuru Nakazawa
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
- * E-mail:
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Su MJ, Chen PW, Ke CC, Chiou SH, Kuo WC, Syu JP. Quantitative evaluation of retinal degeneration in royal college of surgeons rats by contrast enhanced ultrahigh resolution optical coherence tomography. OPHTHALMIC TECHNOLOGIES XXVIII 2018. [DOI: 10.1117/12.2289610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Pi S, Camino A, Zhang M, Cepurna W, Liu G, Huang D, Morrison J, Jia Y. Angiographic and structural imaging using high axial resolution fiber-based visible-light OCT. BIOMEDICAL OPTICS EXPRESS 2017; 8:4595-4608. [PMID: 29082087 PMCID: PMC5654802 DOI: 10.1364/boe.8.004595] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/14/2017] [Accepted: 09/17/2017] [Indexed: 05/20/2023]
Abstract
Optical coherence tomography using visible-light sources can increase the axial resolution without the need for broader spectral bandwidth. Here, a high-resolution, fiber-based, visible-light optical coherence tomography system is built and used to image normal retina in rats and blood vessels in chicken embryo. In the rat retina, accurate segmentation of retinal layer boundaries and quantification of layer thicknesses are accomplished. Furthermore, three distinct capillary plexuses in the retina and the choriocapillaris are identified and the characteristic pattern of the nerve fiber layer thickness in rats is revealed. In the chicken embryo model, the microvascular network and a venous bifurcation are examined and the ability to identify and segment large vessel walls is demonstrated.
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Affiliation(s)
- Shaohua Pi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
- These authors contributed equally to this work
| | - Acner Camino
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
- These authors contributed equally to this work
| | - Miao Zhang
- Optovue Inc. 2800 Bayview Dr., Fremont, CA 94538, USA
| | - William Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Gangjun Liu
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - John Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
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