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Zueva MV, Neroeva NV, Zhuravleva AN, Bogolepova AN, Kotelin VV, Fadeev DV, Tsapenko IV. Fractal Phototherapy in Maximizing Retina and Brain Plasticity. ADVANCES IN NEUROBIOLOGY 2024; 36:585-637. [PMID: 38468055 DOI: 10.1007/978-3-031-47606-8_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
The neuroplasticity potential is reduced with aging and impairs during neurodegenerative diseases and brain and visual system injuries. This limits the brain's capacity to repair the structure and dynamics of its activity after lesions. Maximization of neuroplasticity is necessary to provide the maximal CNS response to therapeutic intervention and adaptive reorganization of neuronal networks in patients with degenerative pathology and traumatic injury to restore the functional activity of the brain and retina.Considering the fractal geometry and dynamics of the healthy brain and the loss of fractality in neurodegenerative pathology, we suggest that the application of self-similar visual signals with a fractal temporal structure in the stimulation therapy can reactivate the adaptive neuroplasticity and enhance the effectiveness of neurorehabilitation. This proposition was tested in the recent studies. Patients with glaucoma had a statistically significant positive effect of fractal photic therapy on light sensitivity and the perimetric MD index, which shows that methods of fractal stimulation can be a novel nonpharmacological approach to neuroprotective therapy and neurorehabilitation. In healthy rabbits, it was demonstrated that a long-term course of photostimulation with fractal signals does not harm the electroretinogram (ERG) and retina structure. Rabbits with modeled retinal atrophy showed better dynamics of the ERG restoration during daily stimulation therapy for a week in comparison with the controls. Positive changes in the retinal function can indirectly suggest the activation of its adaptive plasticity and the high potential of stimulation therapy with fractal visual stimuli in a nonpharmacological neurorehabilitation, which requires further study.
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Affiliation(s)
- Marina V Zueva
- Department of Clinical Physiology of Vision, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Natalia V Neroeva
- Department of Pathology of the Retina and Optic Nerve, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Anastasia N Zhuravleva
- Department of Glaucoma, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Anna N Bogolepova
- Department of neurology, neurosurgery and medical genetics, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Vladislav V Kotelin
- Department of Clinical Physiology of Vision, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Denis V Fadeev
- Scientific Experimental Center Department, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Irina V Tsapenko
- Department of Clinical Physiology of Vision, Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
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2
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Kaczmarek JV, Bogan CM, Pierce JM, Tao YK, Chen SC, Liu Q, Liu X, Boyd KL, Calcutt MW, Bridges TM, Lindsley CW, Friedman DL, Richmond A, Daniels AB. Intravitreal HDAC Inhibitor Belinostat Effectively Eradicates Vitreous Seeds Without Retinal Toxicity In Vivo in a Rabbit Retinoblastoma Model. Invest Ophthalmol Vis Sci 2021; 62:8. [PMID: 34757417 PMCID: PMC8590161 DOI: 10.1167/iovs.62.14.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Purpose Current melphalan-based regimens for intravitreal chemotherapy for retinoblastoma vitreous seeds are effective but toxic to the retina. Thus, alternative agents are needed. Based on the known biology of histone deacetylases (HDACs) in the retinoblastoma pathway, we systematically studied whether the HDAC inhibitor belinostat is a viable, molecularly targeted alternative agent for intravitreal delivery that might provide comparable efficacy, without toxicity. Methods In vivo pharmacokinetic experiments in rabbits and in vitro cytotoxicity experiments were performed to determine the 90% inhibitory concentration (IC90). Functional toxicity by electroretinography and structural toxicity by optical coherence tomography (OCT), OCT angiography, and histopathology were evaluated in rabbits following three injections of belinostat 350 µg (2× IC90) or 700 µg (4× IC90), compared with melphalan 12.5 µg (rabbit equivalent of the human dose). The relative efficacy of intravitreal belinostat versus melphalan to treat WERI-Rb1 human cell xenografts in rabbit eyes was directly quantified. RNA sequencing was used to assess belinostat-induced changes in RB cell gene expression. Results The maximum nontoxic dose of belinostat was 350 µg, which caused no reductions in electroretinography parameters, retinal microvascular loss on OCT angiography, or retinal degeneration. Melphalan caused severe retinal structural and functional toxicity. Belinostat 350 µg (equivalent to 700 µg in the larger human eye) was equally effective at eradicating vitreous seeds in the rabbit xenograft model compared with melphalan (95.5% reduction for belinostat, P < 0.001; 89.4% reduction for melphalan, P < 0.001; belinostat vs. melphalan, P = 0.10). Even 700 µg belinostat (equivalent to 1400 µg in humans) caused only minimal toxicity. Widespread changes in gene expression resulted. Conclusions Molecularly targeted inhibition of HDACs with intravitreal belinostat was equally effective as standard-of-care melphalan but without retinal toxicity. Belinostat may therefore be an attractive agent to pursue clinically for intravitreal treatment of retinoblastoma.
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Affiliation(s)
- Jessica V Kaczmarek
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Carley M Bogan
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Janene M Pierce
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Yuankai K Tao
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Sheau-Chiann Chen
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Qi Liu
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Xiao Liu
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Kelli L Boyd
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - M Wade Calcutt
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Thomas M Bridges
- Warren Center for Neuroscience Drug Discovery at Vanderbilt, Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
| | - Craig W Lindsley
- Warren Center for Neuroscience Drug Discovery at Vanderbilt, Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
| | - Debra L Friedman
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ann Richmond
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, Tennessee, United States.,Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States.,Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, United States
| | - Anthony B Daniels
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, United States.,Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
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Choi KE, Anh VTQ, Oh JH, Yun C, Kim SW. Normative Data of Axial Length, Retinal Thickness Measurements, Visual Evoked Potentials, and Full-Field Electroretinography in Female, Wild-Type Minipigs. Transl Vis Sci Technol 2021; 10:3. [PMID: 34605876 PMCID: PMC8496425 DOI: 10.1167/tvst.10.12.3] [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 The purpose of this study was to present normative data of optical coherence tomography (OCT), electrophysiological, and ocular biometry parameters and their correlation in minipigs. Methods Eighty-eight eyes of 44 minipigs underwent full-field electroretinogram (ERG) recording and ocular biometry. However, 10 eyes of 6 minipigs were excluded because of poor OCT image quality. The thickness of the retinal sublayers was measured on a vertical line at 5 locations with a 1 mm interval from the disc margin to the dorsal periphery and at 10 locations on the visual streak. Visual evoked potentials (VEPs) were measured in 15 eyes of 8 minipigs. Results All minipigs were female with a mean age and axial length of 13.83 ± 10.56 months and 20.33 ± 0.88 mm, respectively. The implicit time of the a-wave and b-wave in scotopic 3.0 ERGs was longer than that in photopic 3.0 ERG. The implicit time of the n2-wave and p2-wave in VEP was 25.67 ± 7.41 ms and 52.96 ± 10.38 ms, respectively. The total retinal layer (TRL) and nerve fiber layer (NFL) became thinner near the periphery. The inner retinal sublayers near the visual streak were thicker than those at other locations. Central TRL and NFL thickness on visual streak was 223.06 ± 23.19 µm and 74.03 ± 13.93 µm, respectively. The temporal TRL and NFL on the visual streak were thicker than those on the nasal side. Conclusions The normative electrophysiological and OCT parameters used in our study can be used as reference data in further pig studies. Translational Relevance This study presents normative data of minipigs, which are adequate animal models for preclinical studies.
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Affiliation(s)
- Kwang-Eon Choi
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Vu Thi Que Anh
- Department of Ophthalmology, Hanoi Medical University, Hanoi, Vietnam
| | - Jong-Hyun Oh
- Department of Ophthalmology, Dongguk University Ilsan Hospital, Goyang, Korea
| | - Cheolmin Yun
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Seong-Woo Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
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de Oliveira RA, Muralha FP, Grupenmacher AT, de Araújo Morandim-Giannetti A, Bersanetti PA, Maia M, Magalhães Junior O. Biocompatibility of polyvinyl alcohol/trisodium trimetaphosphate as vitreous substitute in experimental vitrectomy model in rabbits. J Biomed Mater Res B Appl Biomater 2021; 110:460-466. [PMID: 34328263 DOI: 10.1002/jbm.b.34923] [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] [Received: 02/26/2021] [Revised: 06/12/2021] [Accepted: 07/08/2021] [Indexed: 11/06/2022]
Abstract
Synthetic hydrogels have been proposed as vitreous substitutes recently. This study aims to evaluate the biocompatibility of polyvinyl alcohol (PVA) crosslinked with trisodium trimetaphosphate (SMTP) hydrogel in rabbit vitrectomized eyes. Seven animals were submitted to pars plana vitrectomy and the vitreous was replaced by PVA/SMTP hydrogel. Optical coherence tomography, fluorescein angiogram, clinical, and electrophysiological (ERG) examinations were analyzed at baseline, on postoperative days 7 and 30. The fellow eye was used as the control group. Hydrogel opacification was observed and ERG recordings were reduced in the hydrogel group in rod response, b-wave cone response and flicker. A histological analysis showed retinal disorganization, presence of multinucleated cells, and intraretinal hydrogel particles. The PVA/SMTP hydrogel showed poor biocompatibility. Novel biomaterials compounds should be analyzed in vivo.
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Affiliation(s)
- Ramon Antunes de Oliveira
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Felipe Picanço Muralha
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Alex Treiger Grupenmacher
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | | | - Maurício Maia
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Octaviano Magalhães Junior
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Bogan CM, Kaczmarek JV, Pierce JM, Chen SC, Boyd KL, Calcutt MW, Bridges TM, Lindsley CW, Nadelmann JB, Liao A, Hsieh T, Abramson DH, Francis JH, Friedman DL, Richmond A, Daniels AB. Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study. Br J Ophthalmol 2021; 106:288-296. [PMID: 33972235 PMCID: PMC8788260 DOI: 10.1136/bjophthalmol-2020-318529] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/09/2021] [Accepted: 04/13/2021] [Indexed: 12/22/2022]
Abstract
Background Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort. Methods Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 μg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. Patients: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan. Results Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC90 across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%–79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 μV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged. Conclusions Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.
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Affiliation(s)
- Carley M Bogan
- Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jessica V Kaczmarek
- Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Janene M Pierce
- Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sheau-Chiann Chen
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kelli L Boyd
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Thomas M Bridges
- Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Craig W Lindsley
- Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Albert Liao
- Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Terry Hsieh
- Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - David H Abramson
- Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Jasmine H Francis
- Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Debra L Friedman
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ann Richmond
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Pharmacology, Vanderbilt University, Nashville, Tennessee, USA.,VA Tennessee Valley Healthcare System Nashville Campus, Nashville, Tennessee, USA.,Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Anthony B Daniels
- Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA .,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA.,Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Daniels AB, Pierce JM, Chen SC. Complete preclinical platform for intravitreal chemotherapy drug discovery for retinoblastoma: Assessment of pharmacokinetics, toxicity and efficacy using a rabbit model. MethodsX 2021; 8:101358. [PMID: 34430259 PMCID: PMC8374393 DOI: 10.1016/j.mex.2021.101358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
Current melphalan-based intravitreal chemotherapy regimens for retinoblastoma vitreous seeds are effective, but cause significant ocular toxicity. We describe protocols for each step of a drug discovery pipeline for preclinical development of novel drugs to maximize efficacy and minimize toxicity. These protocols include: 1) determination of vitreous pharmacokinetics in vivo, 2) in vitro assessment of drug cytotoxicity against retinoblastoma based on empiric pharmacokinetics, 3) back-calculation of minimum injection dose to achieve therapeutic concentrations, 4) in vivo determination of maximum-tolerable intravitreal dose, using a multimodal, structural and functional toxicity-assessment platform, and 5) in vivo determination of drug efficacy using a rabbit orthotopic xenograft model of retinoblastoma vitreous seeds. We likewise describe our methodology for direct quantitation of vitreous seeds, and the statistical methodology for assessment of toxicity and efficacy in evaluating novel drugs, as well as for comparisons between drugs.•Multi-step pipeline for intravitreal chemotherapy drug discovery for retinoblastoma, using novel rabbit models.•Detailed protocols for determination of vitreous pharmacokinetics, calculation of optimal dose to inject to achieve therapeutic vitreous levels, determination of maximum tolerable dose using a novel complete toxicity-assessment platform, and in vivo efficacy against retinoblastoma using methodology to directly quantify vitreous tumor burden.•Associated statistical methodology is also presented.
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Affiliation(s)
- Anthony B Daniels
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, United States.,Program in Cancer Biology, Vanderbilt University, Nashville, TN, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Janene M Pierce
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sheau-Chiann Chen
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States
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Bogan CM, Pierce JM, Doss SD, Tao YK, Chen SC, Boyd KL, Liao A, Hsieh T, Abramson DH, Francis JH, Friedman DL, Richmond A, Daniels AB. Intravitreal melphalan hydrochloride vs propylene glycol-free melphalan for retinoblastoma vitreous seeds: Efficacy, toxicity and stability in rabbits models and patients. Exp Eye Res 2021; 204:108439. [PMID: 33444583 PMCID: PMC8117559 DOI: 10.1016/j.exer.2021.108439] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/15/2020] [Accepted: 01/05/2021] [Indexed: 11/22/2022]
Abstract
The use of intravitreal chemotherapy has revolutionized the treatment of advanced intraocular retinoblastoma, as intravitreal melphalan has enabled difficult-to-treat vitreous tumor seeds to be controlled, leading to many more eyes being saved. However, melphalan hydrochloride (MH) degrades rapidly in solution, increasing logistical complexity with respect to time between medication preparation and administration for intravitreal administration under anesthesia for retinoblastoma. A new propylene glycol-free melphalan (PGFM) formulation has greater stability and could therefore improve access and adoption of intravitreal chemotherapy, allowing more children to retain their eye(s). We compared the efficacy and toxicity of both formulations, using our rabbit xenograft model and clinical patient experience. Three weekly 12.5 μg intravitreal injections of MH or PGFM (right eye), and saline (left eye), were administered to immunosuppressed rabbits harboring human WERI-Rb1 vitreous seed xenografts. Residual live cells were quantified directly, and viability determined by TUNEL staining. Vitreous seeds were reduced 91% by PGFM (p = 0.009), and 88% by MH (p = 0.004; PGFM vs. MH: p = 0.68). All residual cells were TUNEL-positive (non-viable). In separate experiments to assess toxicity, three weekly 12.5 μg injections of MH, PGFM, or saline were administered to non-tumor-bearing rabbits. Serial electroretinography, optical coherence tomography (OCT) and OCT-angiography were performed. PGFM and MH both caused equivalent reductions in electroretinography amplitudes, and loss of retinal microvasculature on OCT-angiography. The pattern of retinal degeneration observed on histopathology suggested that segmental retinal toxicity associated with all melphalan formulations was due to a vitreous concentration gradient-effect. Efficacy and toxicity were assessed for PGFM given immediately (within 1 h of reconstitution) vs. 4 h after reconstitution. Immediate- and delayed-administration of PGFM showed equivalent efficacy and toxicity. In addition, we evaluated efficacy and toxicity in patients (205 eyes) with retinoblastoma vitreous seeds, who were treated with a total of 833 intravitreal injections of either MH or PGFM as standard of care. Of these, we analyzed 118 MH and 131 PGFM monotherapy injections in whom serial ERG measurements were available to model retinal toxicity. Both MH and PGFM caused reductions in electroretinography amplitudes, but with no statistical difference between formulations. Comparing those patient eyes treated exclusively with PGFM versus those treated exclusively with MH, efficacy for tumor control and globe salvage was equivalent (PGFM vs. MH: 96.2% vs. 93.8%, p = 0.56), but PGFM-treated eyes received fewer injections than MH-treated eyes (average 3.2 ± 1.9 vs. 6.4 ± 2.1 injections, p < 0.0001). Taken together, these rabbit experiments and our clinical experience in retinoblastoma patients demonstrate that MH and PGFM have equivalent efficacy and toxicity. PGFM was more stable, with no decreased efficacy or increased toxicity even 4 h after reconstitution. We therefore now use PGFM over traditional MH for our patients for intravitreal treatment of retinoblastoma.
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Affiliation(s)
- Carley M Bogan
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Janene M Pierce
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephanie D Doss
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuankai K Tao
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Sheau-Chiann Chen
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelli L Boyd
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Albert Liao
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Terry Hsieh
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | | | - Debra L Friedman
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ann Richmond
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA; Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA; Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
| | - Anthony B Daniels
- Division of Ocular Oncology and Pathology, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA; Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA; Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, USA.
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8
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Glickman RD, Onorato M, Campos MM, O'Boyle MP, Singh RK, Zarembinski TI, Binette F, Nasonkin IO. Intraocular Injection of HyStem Hydrogel Is Tolerated Well in the Rabbit Eye. J Ocul Pharmacol Ther 2021; 37:60-71. [PMID: 33449859 DOI: 10.1089/jop.2020.0042] [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: 11/12/2022] Open
Abstract
Purpose: To determine the long-term biocompatibility of HyStem® hydrogel in the rabbit eye for use as a carrier for cell or drug delivery into the ocular space. Methods: HyStem hydrogel formulation solidifies ∼20 min after reconstitution, thus can potentially form a solid deposit after injection in situ. To study the ocular disposition of fluorescein-labeled HyStem, we delivered 50 μL/eye over 1 min into the vitreous space of the rabbit. We used 3 Dutch-Belted and 3 New Zealand-pigmented rabbits, all females, delivered the gel into the right eyes, and injected 50 μL BSS Plus into the left eyes as a control. Retinal morphology was assessed by optical coherence tomography (OCT) and white light fundus photography. Fluorescence fundus photography enabled measurement of the clearance of the labeled hydrogel from the posterior chamber. Visual function was evaluated using flash and flicker electroretinography (ERG) pre- and postinjection and at weekly intervals thereafter for 6 weeks. Retinal immunohistochemistry for microglial inflammatory markers was carried out with antiglial fibrillary acidic protein (GFAP) antibody, isolectin B4 (IB4), and 4',6-diamidino-2-phenylindole (DAPI). Results: The gel was successfully delivered into the vitreous space without the formation of a discrete retinal deposit. Fundus imaging, OCT measurements of retinal thickness, and immunohistochemical data indicated an absence of retinal inflammation, and ERG indicated no impact on retinal function. The half-time of HyStem clearance calculated from the loss of fundus fluorescence was 3.9 days. Conclusions: HyStem hydrogel appears to be biocompatible in the ocular space of a large eye and safe for long-term intraocular application.
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Affiliation(s)
- Randolph D Glickman
- Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | | | - Maria M Campos
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael P O'Boyle
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Abd-Elhakim YM, El Bohi KM, El Sharkawy NI, Ghali MA, Haseeb S. The impacts of individual and combined exposure to cadmium and lead on intraocular pressure, electroretinography, and residual changes in the rabbit eyes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:33321-33328. [PMID: 31520382 DOI: 10.1007/s11356-019-06446-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
The human eye is very vulnerable to various environmental pollutants. Cadmium (Cd) and lead (Pb) are widely spread heavy metals. The goal of the existing study is to explore the impact of single or joint exposure to Cd and Pb on the eye indicators. In this study, male New Zealand white rabbits were treated orally for 30 days with Cd (5 mg Cd Cl2/kg bw) associated or not with Pb (12.5 mg lead acetate/kg bw). Fundus and slit lamp examinations, electroretinography (ERG), intraocular pressure (IOP), Cd and Pb residues, and the histopathological picture of the eye were studied. The results revealed that the oral dosing of Cd or Pb evoked a significant (p < 0.05) decline in a- and b-wave amplitudes, under scotopic conditions, and IOP values. Single Pb or Cd treatment showed a significant (p < 0.001) increase in their residues in the whole eye tissue of the Pb- or Cd-treated group. Eye structures of Cd- or Pb-intoxicated rabbit showed mild degenerated changes of cornea and sclera tissues with the presence of irregular variably sized eosinophilic droplets in the lens. Notably, the simultaneous exposure to Cd and Pb leads to an antagonistic outcome in all of the estimated parameters. These findings concluded that oral exposure to Cd or Pb could significantly disturb the vision but their joint exposure caused an opposing effect on nearly all of these disturbances.
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Affiliation(s)
- Yasmina M Abd-Elhakim
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
| | - Khlood M El Bohi
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Nabela I El Sharkawy
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Manar A Ghali
- Ophthalmology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Sarah Haseeb
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
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10
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Ahn SM, Ahn J, Cha S, Yun C, Park TK, Kim YJ, Goo YS, Kim SW. The effects of intravitreal sodium iodate injection on retinal degeneration following vitrectomy in rabbits. Sci Rep 2019; 9:15696. [PMID: 31666618 PMCID: PMC6821727 DOI: 10.1038/s41598-019-52172-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/12/2019] [Indexed: 11/17/2022] Open
Abstract
We sought to develop and characterize outer retinal degeneration induced by intravitreal injection of sodium iodate (SI) after vitrectomy in rabbits. To determine the effective dose of SI, the right eyes of 19 male New Zealand white rabbits received an intravitreal injection of SI or sham. Based on the dose-dependence results, 0.4 mg of SI in 0.05 mL of total volume was injected into the right eyes of 10 rabbits at two weeks after vitrectomy. In the dose-dependence study, localized retinal atrophy was observed with 0.3- and 0.4-mg SI injections without vitrectomy. Severe and diffuse retinal atrophy was identified by spectral-domain optical coherence tomography (SD-OCT) at one month after a 0.5-mg SI injection following vitrectomy. In the second experiment, 0.4 mg of SI in 0.05 mL was injected, and the severity of outer retinal degeneration was graded as one of two types according to electroretinography (ERG) response change. There was no response on ERG in complete retinal degeneration, 30% of all 10 rabbits. Intravitreal injection of 0.4 mg of SI into vitrectomized rabbit eyes induces diffuse outer retinal degeneration, and the degree of retinal degeneration can be evaluated through in vivo ophthalmic examination.
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Affiliation(s)
- So Min Ahn
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Jungryul Ahn
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Korea
| | - Seongkwang Cha
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Korea
| | - Cheolmin Yun
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Tae Kwann Park
- Department of Ophthalmology, Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea
| | - Young-Jin Kim
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Korea
| | - Yong Sook Goo
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Korea.
| | - Seong-Woo Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
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11
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Daniels AB, Froehler MT, Nunnally AH, Pierce JM, Bozic I, Stone CA, Santapuram PR, Tao YK, Boyd KL, Himmel LE, Chen SC, Du L, Friedman DL, Richmond A. Rabbit Model of Intra-Arterial Chemotherapy Toxicity Demonstrates Retinopathy and Vasculopathy Related to Drug and Dose, Not Procedure or Approach. Invest Ophthalmol Vis Sci 2019; 60:954-964. [PMID: 30882851 PMCID: PMC6424472 DOI: 10.1167/iovs.18-25346] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose To use our intra-arterial chemotherapy (IAC) rabbit model to assess the impact of IAC procedure, drug, dose, and choice of technique on ocular structure and function, to study the nature and etiology of IAC toxicity, and to compare to observations in patients. Methods Rabbits received IAC melphalan (0.4-0.8 mg/kg), carboplatin (25–50 mg), or saline, either by direct ophthalmic artery cannulation, or with a technique emulating nonocclusion. Ocular structure/function were assessed with examination, electroretinography (ERG), fundus photography, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography, prior to and 5 to 6 weeks after IAC. Blood counts were obtained weekly. We reviewed our last 50 IAC treatments in patients for evidence of ocular or systemic complications. Results No toxicity was seen in the saline control group. With standard (0.4 mg/kg) melphalan, no vascular/microvascular abnormalities were seen with either technique. However, severe microvascular pruning and arteriolar occlusions were seen occasionally at 0.8 mg/kg doses. ERG reductions were dose-dependent. Histology showed melphalan dose-dependent degeneration in all retinal layers, restricted geographically to areas of greatest vascular density. Carboplatin caused massive edema of ocular/periocular structures. IAC patients experienced occasional periocular swelling/rash, and only rarely experienced retinopathy or vascular events/hemorrhage in eyes treated multiple times with triple (melphalan/carboplatin/topotecan) therapy. Transient neutropenia occurred after 46% of IAC procedures, generally after triple therapy. Conclusions IAC toxicity appears to be related to the specific drug being used and is dose-dependent, rather than related to the IAC procedure itself or the specific technique selected. These rabbit findings are corroborated by our clinical findings in patients.
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Affiliation(s)
- Anthony B Daniels
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Michael T Froehler
- Cerebrovascular Program, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Amy H Nunnally
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Janene M Pierce
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ivan Bozic
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Cameron A Stone
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Pranav R Santapuram
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Yuankai K Tao
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Kelli L Boyd
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Lauren E Himmel
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Sheau-Chiann Chen
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Liping Du
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Debra L Friedman
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ann Richmond
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, Tennessee, United States.,Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
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12
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Evangelho K, Mastronardi CA, de-la-Torre A. Experimental Models of Glaucoma: A Powerful Translational Tool for the Future Development of New Therapies for Glaucoma in Humans-A Review of the Literature. MEDICINA (KAUNAS, LITHUANIA) 2019; 55:E280. [PMID: 31212881 PMCID: PMC6630440 DOI: 10.3390/medicina55060280] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022]
Abstract
Glaucoma is a common complex disease that leads to irreversible blindness worldwide. Even though preclinical studies showed that lowering intraocular pressure (IOP) could prevent retinal ganglion cells loss, clinical evidence suggests that lessening IOP does not prevent glaucoma progression in all patients. Glaucoma is also becoming more prevalent in the elderly population, showing that age is a recognized major risk factor. Indeed, recent findings suggest that age-related tissue alterations contribute to the development of glaucoma and have encouraged exploration for new treatment approaches. In this review, we provide information on the most frequently used experimental models of glaucoma and describe their advantages and limitations. Additionally, we describe diverse animal models of glaucoma that can be potentially used in translational medicine and aid an efficient shift to the clinic. Experimental animal models have helped to understand the mechanisms of formation and evacuation of aqueous humor, and the maintenance of homeostasis of intra-ocular pressure. However, the transfer of pre-clinical results obtained from animal studies into clinical trials may be difficult since the type of study does not only depend on the type of therapy to be performed, but also on a series of factors observed both in the experimental period and the period of transfer to clinical application. Conclusions: Knowing the exact characteristics of each glaucoma experimental model could help to diminish inconveniences related to the process of the translation of results into clinical application in humans.
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Affiliation(s)
- Karine Evangelho
- Doctorado en Ciencias Biomédicas y Biológicas, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá,11121, Colombia.
| | - Claudio A Mastronardi
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
| | - Alejandra de-la-Torre
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
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13
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Liu S, Chen X, Su Y, Qiu L, Chen X, Yan D, Yao X, Guo S, Yi C. Association of Autologous Fat Injection in Facial Artery With Ophthalmological Complications: An Experimental Animal Study. JAMA FACIAL PLAST SU 2018; 20:445-451. [PMID: 29978203 DOI: 10.1001/jamafacial.2017.1975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Complications caused by autologous fat filling have been reported. Comprehensive knowledge of the possible adverse effects of autologous fat filling is needed. Objective To determine the association of autologous fat filling with ophthalmic function complications. Design, Setting, and Participants Four adult New Zealand white rabbits were killed for a facial anatomy study. Sixty-four adult New Zealand white rabbits underwent fat harvest using the Coleman technique. Autologous fat was minced or digested with collagenase 1 and centrifuged to separate fat lipid and fat granules. Either 0.2 mL or 0.4 mL of minced fat, fat granules, fat lipid, or saline (control) was retrogradely injected into the facial artery of rabbit models. Electroretinography and ophthalmic fundoscopy were performed to measure the retina and fundus artery occlusions 2 weeks after surgery. Main Outcomes and Measures Visual impairment, blindness, and death. Results Injection of 0.2 mL of fat granules, fat lipid, and saline resulted in 100% (8 of 8), 62.5% (5 of 8), and 0 ophthalmic complications, respectively; and 0.4 mL resulted in 87.5% (7 of 8), 12.5% (1 of 8), and 0 ophthalmic complications, respectively. Injection of 0.2 mL and 0.4 mL minced fat led to 100% (8 of 8) ophthalmic complications and death, respectively. The mortality rates were 37.5% (3 of 8), 12.5% (1 of 8), and 0 for 0.2 mL emboli injection, and 100% (8 of 8), 50% (4 of 8), and 0 for 0.4 mL, respectively. Conclusions and Relevance In this study, minced fat injection was associated with more ophthalmic complications than injection of fat granules and fat lipid. Increasing the injection volume of fat tissues could raise the incidence of morbidity and mortality. Level of Evidence NA.
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Affiliation(s)
- Sha Liu
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, China.,Department of Burn and Plastic Surgery, the 253rd hospital of PLA, Hohhot, Inner Mongolia, China
| | - Xi Chen
- Department of Prosthodontics, School of Stomatology, the Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yingjun Su
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Lihong Qiu
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiangjun Chen
- Department of Burn and Plastic Surgery, the 253rd hospital of PLA, Hohhot, Inner Mongolia, China
| | - Dexiong Yan
- Department of Burn and Plastic Surgery, the 253rd hospital of PLA, Hohhot, Inner Mongolia, China
| | - Xingwei Yao
- Department of Burn and Plastic Surgery, the 253rd hospital of PLA, Hohhot, Inner Mongolia, China
| | - Shuzhong Guo
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Chenggang Yi
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, China
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14
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Daniels AB, Froehler MT, Pierce JM, Nunnally AH, Calcutt MW, Bridges TM, LaNeve DC, Williams PE, Boyd KL, Reyzer ML, Lindsley CW, Friedman DL, Richmond A. Pharmacokinetics, Tissue Localization, Toxicity, and Treatment Efficacy in the First Small Animal (Rabbit) Model of Intra-Arterial Chemotherapy for Retinoblastoma. Invest Ophthalmol Vis Sci 2018; 59:446-454. [PMID: 29368001 PMCID: PMC5783625 DOI: 10.1167/iovs.17-22302] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Current intra-arterial chemotherapy (IAC) drug regimens for retinoblastoma have ocular and vascular toxicities. No small-animal model of IAC exists to test drug efficacy and toxicity in vivo for IAC drug discovery. The purpose of this study was to develop a small-animal model of IAC and to analyze the ocular tissue penetration, distribution, pharmacokinetics, and treatment efficacy. Methods Following selective ophthalmic artery (OA) catheterization, melphalan (0.4 to 1.2 mg/kg) was injected. For pharmacokinetic studies, rabbits were euthanized at 0.5, 1, 2, 4, or 6 hours following intra-OA infusion. Drug levels were determined in vitreous, retina, and blood by liquid chromatography tandem mass spectrometry. To assess toxicity, angiograms, photography, fluorescein angiography, and histopathology were performed. For in situ tissue drug distribution, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) was performed. The tumor model was created by combined subretinal/intravitreal injection of human WERI-Rb1 retinoblastoma cells; the tumor was treated in vivo with intra-arterial melphalan or saline; and induction of tumor death was measured by cleaved caspase-3 activity. Results OA was selectively catheterized for 79 of 79 (100%) eyes in 47 of 47 (100%) rabbits, and melphalan was delivered successfully in 31 of 31 (100%) eyes, without evidence of vascular occlusion or retinal damage. For treated eyes, maximum concentration (Cmax) in the retina was 4.95 μM and area under the curve (AUC0→∞) was 5.26 μM·h. Treated eye vitreous Cmax was 2.24 μM and AUC0→∞ was 4.19 μM·h. Vitreous Cmax for the treated eye was >100-fold higher than for the untreated eye (P = 0.01), and AUC0→∞ was ∼50-fold higher (P = 0.01). Histology-directed MALDI-IMS revealed highest drug localization within the retina. Peripheral blood Cmax was 1.04 μM and AUC0→∞ was 2.07 μM·h. Combined subretinal/intravitreal injection of human retinoblastoma cells led to intra-retinal tumors and subretinal/vitreous seeds, which could be effectively killed in vivo with intra-arterial melphalan. Conclusions This first small-animal model of IAC has excellent vitreous and retinal tissue drug penetration, achieving levels sufficient to kill human retinoblastoma cells, facilitating future IAC drug discovery.
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Affiliation(s)
- Anthony B Daniels
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee, United States.,Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Michael T Froehler
- Cerebrovascular Program, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Janene M Pierce
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Amy H Nunnally
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Surgical Research, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - M Wade Calcutt
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Thomas M Bridges
- Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
| | - David C LaNeve
- Surgical Research, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Phillip E Williams
- Surgical Research, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Kelli L Boyd
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Michelle L Reyzer
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Craig W Lindsley
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States.,Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Debra L Friedman
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ann Richmond
- Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee, United States.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, Tennessee, United States
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15
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Changes in Retinal Function and Cellular Remodeling Following Experimental Retinal Detachment in a Rabbit Model. J Ophthalmol 2017; 2017:4046597. [PMID: 28491466 PMCID: PMC5401754 DOI: 10.1155/2017/4046597] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/29/2017] [Accepted: 02/13/2017] [Indexed: 11/17/2022] Open
Abstract
Purpose. To explore functional electroretinographic (ERG) changes and associated cellular remodeling following experimental retinal detachment in a rabbit model. Methods. Retinal detachment was created in ten rabbits by injecting 0.1 ml balanced salt solution under the retina. Fundus imaging was performed 0, 3, 7, 14, and 21 days postoperatively. ERGs were recorded pre- and 7 and 21 days postoperatively. Eyes were harvested on day 21 and evaluated immunohistochemically (IHC) for remodeling of second- and third-order neurons. Results. Retinal reattachment occurred within two weeks following surgery. No attenuation was observed in the photopic or scotopic a- and b-waves. A secondary wavefront on the descending slope of the scotopic b-wave was the only ERG result that was attenuated in detached retinas. IHC demonstrated anatomical changes in both ON and OFF bipolar cells. Bassoon staining was observed in the remodeled dendrites. Amacrine and horizontal cells did not alter, but Muller cells were clearly reactive with marked extension. Conclusion. Retinal detachment and reattachment were associated with functional and anatomical changes. Exploring the significance of the secondary scotopic wavefront and its association with the remodeling of 2nd- and 3rd-order neurons will shade more light on functional changes and recovery of the retina.
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16
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Test–retest reliability of scotopic full-field electroretinograms in rabbits. Doc Ophthalmol 2017; 134:157-165. [DOI: 10.1007/s10633-017-9582-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
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17
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Schnichels S, Schneider N, Hohenadl C, Hurst J, Schatz A, Januschowski K, Spitzer MS. Efficacy of two different thiol-modified crosslinked hyaluronate formulations as vitreous replacement compared to silicone oil in a model of retinal detachment. PLoS One 2017; 12:e0172895. [PMID: 28248989 PMCID: PMC5332068 DOI: 10.1371/journal.pone.0172895] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/10/2017] [Indexed: 01/28/2023] Open
Abstract
The efficacy of two novel artificial vitreous body substitutes (VBS) consisting of highly biocompatible thiolated cross-linked hyaluronic acid (HA)-based hydrogels in comparison to silicone oil in a model of retinal detachment was investigated. Pars plana vitrectomy (23G) was performed in the right eye of 24 pigmented rabbits. Retinal detachment of two quadrants was induced by creating a small retinotomy near the vascular arcade and injecting balanced salt solution (BSS) subretinally. The retina was reattached by injecting air, which was followed by increasing the infusion pressure, and the retinal tear was treated by endolaser photocoagulation. At the end of the procedure, the eye was filled either with 5000-cs silicone oil (after fluid air exchange) or the respective hydrogel (with two different viscosities). Follow-up examination included slit lamp examination, funduscopy, intraocular pressure measurements (IOP), optical coherence tomography (OCT) and electroretinogram (ERG) measurements. After a maximum follow-up of four weeks both eyes were removed, examined macroscopically, photographed, and prepared for histology. Of the eight rabbits that received silicone oil, seven (87.5%) developed a recurrent retinal detachment with pronounced proliferative vitreoretinopathy within the first two weeks after surgery. In contrast, in the hydrogel treated eyes, the retina stayed attached in the majority of the cases (73.3%). IOP and retinal morphology were normal as long as the retina remained re-attached. In conclusions, this model of retinal detachment, both thiolated crosslinked hyaluronate hydrogels showed superior efficacy when compared to silicone oil. These hydrogels have a promising potential as novel vitreous body substitutes.
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Affiliation(s)
- Sven Schnichels
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | - Nele Schneider
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | | | - José Hurst
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | - Andreas Schatz
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | - Kai Januschowski
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | - Martin S. Spitzer
- Centre of Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, Hamburg, Germany
- * E-mail:
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18
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Barth H, Crafoord S, Andréasson S, Ghosh F. A cross-linked hyaluronic acid hydrogel (Healaflow®) as a novel vitreous substitute. Graefes Arch Clin Exp Ophthalmol 2016; 254:697-703. [DOI: 10.1007/s00417-015-3256-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 12/13/2015] [Accepted: 12/24/2015] [Indexed: 12/01/2022] Open
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19
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Myers AC, Ghosh F, Andréasson S, Ponjavic V. Retinal function and morphology in the rabbit eye after intravitreal injection of the TNF alpha inhibitor adalimumab. Curr Eye Res 2014; 39:1106-16. [PMID: 24897597 PMCID: PMC4238743 DOI: 10.3109/02713683.2014.898309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aim To study the effects of the tumor necrosis factor alpha inhibitor adalimumab on rabbit retina after injection into the vitreous body. Methods Forty-eight rabbits of mixed strain (9–12 months old, weighing ≈ 3.5 kg) were randomized into four groups. Adalimumab was injected at one of two concentrations (1.25 mg or 2.5 mg) into the eyes of two groups, and balanced salt solution into the eyes of the third group. The fourth group acted as controls. Full-field electroretinography (ffERG) was performed before injection and 1 and 6 weeks post-injection. At 6 weeks post-injection the rabbits were euthanized and the sectioned retinas were studied. Retinal histology was studied with hematoxylin–eosin staining. Immunohistochemical analysis was performed on rods, cones, rod bipolar cells, horizontal cells, amacrine cells and Müller cells. Results No significant difference in ffERG amplitudes or implicit times was observed between the four groups at any time point. Histological and immunohistochemical findings were similar in all groups. Conclusions Injection of adalimumab into the vitreous body of healthy rabbits, at doses up to 2.5 mg, does not appear to be toxic to the rabbit retina.
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20
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Myers AC, Bruun A, Ghosh F, Adrian ML, Andréasson S, Ponjavic V. Intravitreal injection of triamcinolone acetonide into healthy rabbit eyes alters retinal function and morphology. Curr Eye Res 2013; 38:649-61. [PMID: 23537282 DOI: 10.3109/02713683.2012.750367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIM To study the effects of intravitreally injected triamcinolone acetonide (TA) and/or its preservative benzyl alcohol (BA) in healthy rabbit retina. METHODS Forty-eight rabbits (aged 4 months, body weight ≈3 kg) were randomized into four groups (n = 12). They were examined with electroretinography (ERG) prior to drug exposure, and then injected intravitreally with a combination of TA and BA, TA without BA, BA alone or a balanced saline solution (BSS). The electroretinograms were assessed 1 week and 7 weeks post-injection. The rabbits were euthanized and the sectioned retinas were studied. Immunohistochemical analysis was performed on rods, cones, rod bipolar cells, horizontal cells, amacrine cells and Müller cells. RESULTS Rabbits injected with BA showed a significantly lower rod-mediated b-wave amplitude than the controls 1 week after injection. TA-injected rabbits demonstrated significantly higher a- and b-wave amplitudes in the total retinal response than the controls 1 week post-injection. The rabbits injected with TA + BA demonstrated a significantly higher b-wave amplitude in the total retinal response than the controls 1 week after injection. The significantly higher a-wave amplitude in the total retinal response remained in the TA-injected rabbits 7 weeks after injection. Immunohistochemistry revealed that protein kinase C alpha (PKC α) was down-regulated in both the perikarya and the axons of bipolar cells in histological sections from rabbit retina injected with TA + BA, BA and TA. CONCLUSIONS Intravitreal injection of the preservative BA reduces the isolated rod-mediated retinal response in the rabbit, transiently and selectively. Intravitreal injection of TA increases the total retinal response in the rabbit up to seven weeks after injection. The effects observed are not only limited to retinal function, but also include changes in the expression of PKC α in rod bipolar cells, indicating drug-related interference with normal retinal physiology in the healthy rabbit eye.
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Myers AC, Lövestam Adrian M, Bruun A, Ghosh F, Andréasson S, Ponjavic V. Retinal function and morphology in rabbit after intravitreal injection of VEGF inhibitors. Curr Eye Res 2012; 37:399-407. [PMID: 22510009 DOI: 10.3109/02713683.2011.611609] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE/AIM To explore changes in morphology and function in the rabbit retina after intravitreal high-dose injection of three commonly used VEGF inhibitors. MATERIALS AND METHODS Forty-eight rabbits of mixed strain (6 months of age, body weight ≈ 3 kg) were randomized into four groups (n = 12). They were examined with full-field electroretinography (ERG) and with multifocal electroretinography (mf ERG) prior to drug exposure. The rabbits were then injected intravitreally with bevacizumab, ranibizumab, pegaptanib, or with a balanced saline solution. The dose of VEGF inhibitor was chosen to achieve a vitreous concentration approximately three times higher than the one clinically used in the adult human eye. ERG was then performed 8 weeks postinjection, and mf ERG 9 weeks postinjection. After 9 weeks, the rabbits were sacrificed and the sectioned retina was studied. Immunohistochemical analysis was performed of rods, cones, rod bipolar cells, horizontal cells, and amacrine cells. RESULTS Rabbits injected with VEGF inhibitors all showed significantly lower amplitude of the dark-adapted b-wave rod-mediated response to dim light, compared to the rabbits injected with BSS. The a wave (reflecting photoreceptor function) in the response to single flash white light was however not affected. Immunohistochemistry revealed a significant reduction in PKC labeling of rod bipolar cells in pegaptanib and ranibizumab injected eyes whereas bevacizumab injected eyes displayed normal PKC labeling. No apparent morphological change was seen with markers for remaining retinal cells. CONCLUSIONS Our results indicate that the use of high-dose intravitreal VEGF inhibitors in the rabbit eye affects rod-mediated retinal function and PKC expression in rod bipolars cells for at least 9 weeks after drug administration. The three VEGF inhibitors influence the retina slightly differently. These results are important for the understanding of drug action and when devising therapeutical strategies in new areas such as retinopathy of prematurity where vitreous volume is significantly lower compared to the adult eye.
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Wang CH, Hwang YS, Chiang PR, Shen CR, Hong WH, Hsiue GH. Extended Release of Bevacizumab by Thermosensitive Biodegradable and Biocompatible Hydrogel. Biomacromolecules 2011; 13:40-8. [DOI: 10.1021/bm2009558] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Chau-Hui Wang
- Polymer Technology
Division,
Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, 300 Taiwan,
Republic of China
| | - Yih-Shiou Hwang
- Department
of Ophthalmology, Chang Gung Memorial Hospital, Linkou, 333 Taiwan, Republic
of China
| | - Ping-Ray Chiang
- Department of
Chemical Engineering, National Tsing Hua University, Hsinchu, 300 Taiwan,
Republic of China
| | | | - Wei-Hsin Hong
- Department
of Ophthalmology, Chang Gung Memorial Hospital, Linkou, 333 Taiwan, Republic
of China
| | - Ging-Ho Hsiue
- Department of
Chemical Engineering, National Tsing Hua University, Hsinchu, 300 Taiwan,
Republic of China
- Department of Chemical Engineering/R&D Center for Membrane Technology, Chung Yuan University, Chung Li, 320 Taiwan, Republic of China
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Experimental vitreous tamponade using polyalkylimide hydrogel. Graefes Arch Clin Exp Ophthalmol 2011; 249:1167-74. [DOI: 10.1007/s00417-011-1652-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 12/08/2010] [Accepted: 02/01/2011] [Indexed: 11/30/2022] Open
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Pritchard CD, Crafoord S, Andréasson S, Arnér KM, O'Shea TM, Langer R, Ghosh FK. Evaluation of viscoelastic poly(ethylene glycol) sols as vitreous substitutes in an experimental vitrectomy model in rabbits. Acta Biomater 2011; 7:936-43. [PMID: 21081184 DOI: 10.1016/j.actbio.2010.11.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/22/2010] [Accepted: 11/10/2010] [Indexed: 12/01/2022]
Abstract
The aim of this study was to employ an experimental protocol for in vivo evaluation of sols of 5 wt.% poly(ethylene glycol) (PEG) in phosphate-buffered saline as artificial vitreous substitutes. A 20 gauge pars plana vitrectomy and posterior vitreous detachment were performed in the right eye of eight pigmented rabbits. Approximately 1 ml of the viscoelastic PEG sols was then injected into the vitreous space of six eyes. PEG with an average molecular weight of 300,000 and 400,000 g mol(-1) was used in two and four eyes, respectively. Two eyes received balanced salt solution and served as controls. Full-field electroretinography was carried out and intra-ocular pressure (IOP, palpation) measured pre- and post-operatively at regular intervals up to 41 days. The rabbits were killed and the eyes examined by retinal photography, gross macroscopic examination and histology. The viscoelastic sols were successfully injected and remained translucent throughout the post-operative period, with some inferior formation of precipitates. None of the eyes displayed IOP elevation post-operatively, but in three of the PEG sol injected eyes transient hypotony was noted. One eye sustained retinal detachment during surgery and another two in the post-operative period. ERG recordings confirmed preservation of retinal function in three out of four eyes injected with 400,000 g mol(-1) PEG. Histological examination revealed up-regulation of glial acidic fibrillary protein in Müller cells in PEG sol injected eyes, but normal overall morphology in eyes with attached retinas. The viscosity of the sol was not retained throughout the post-operative period, indicating the demand for polymer cross-linking to increase residence time. The results provide promising preliminary results on the use of PEG hydrogels as a vitreous substitute.
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Affiliation(s)
- Christopher D Pritchard
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Yokoyama D, Machida S, Kondo M, Terasaki H, Nishimura T, Kurosaka D. Pharmacological dissection of multifocal electroretinograms of rabbits with Pro347Leu rhodopsin mutation. Jpn J Ophthalmol 2010; 54:458-66. [PMID: 21052910 DOI: 10.1007/s10384-010-0842-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 03/29/2010] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine whether photoreceptor degeneration in transgenic (Tg) rabbits carrying the Pro347Leu rhodopsin mutation alters the neural activity of the middle and inner retinal neurons. METHODS Multifocal electroretinograms (mfERGs) were recorded from eight 12-week-old Tg rabbits both before and after intravitreal injection of the following: tetrodotoxin citrate (TTX), N-methyl-DL: -aspartic acid (NMDA), 2-amino-4-phosphonobutyric acid (APB), and cis-2,3-piperidine-dicarboxylic acid (PDA). Digital subtraction of the mfERGs recorded after the drugs were administered from those recorded before was used to extract the components that were eliminated by these drugs. Eight agematched, wild-type (WT) rabbits were studied with the same protocol. RESULTS There was no reduction in the amplitude of the cone photoreceptor response of the mfERGs in Tg rabbits. Both the first positive and the first negative waves of the ON-bipolar cell responses were significantly larger in the Tg than in the WT rabbits. Late negative waves of the ON-bipolar cell response were recorded only in the WT rabbits. The first negative wave of the inner retinal responses was larger in the Tg than in the Wt rabbits. The late positive waves were seen mainly in the WT rabbits. CONCLUSIONS The ON-bipolar cell and inner retinal responses were altered at the early stage of photoreceptor degeneration in Tg rabbits despite the preservation of the cone photoreceptor responses.
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Affiliation(s)
- Daisuke Yokoyama
- Department of Ophthalmology, Iwate Medical University School of Medicine, Morioka, Iwate, Japan
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Li X, Cai C, Li L, Chai X, Ren Q. Low-hemorrhage-risk surgical approach to expose the optic nerve in rabbits without bony removal and rectus resection. Vet Ophthalmol 2009; 12:227-33. [PMID: 19604338 DOI: 10.1111/j.1463-5224.2009.00707.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE A low-hemorrhage-risk surgical approach to expose the optic nerve (ON) in rabbits through the orbital process of the frontal bone without removal of the bony orbit and resection of the rectus muscle was explored and assessed in this study. This approach will be used to investigate a new visual prosthesis that requires intraorbital ON stimulation with penetrating electrodes. Animals Chinese Albino rabbits (n = 10). METHODS Rabbits were classified into a surgery and a control group (five in each). In the surgery group, the ON exposure was explored by the newly proposed surgical approach. Surgical time, blood loss, visually evoked potentials (VEP) at four different scheduled time points, and H&E-stained histology of the ON at one month after surgery were recorded and analyzed to assess the ease and safety of the approach. RESULTS The average surgical time for the ON exposure was 16.40 +/- 1.14 min with average blood loss of 0.52 +/- 0.08 mL. Within the one-month follow-up, the ON exhibited a naturally reversible conduction change in terms of VEP amplitude. Histological examination of the ON was unremarkable. A postoperative mild ptosis of the surgical eye resolved within one month after surgery. CONCLUSION The ease and safety of this new surgical approach allowed it to be easily used by non-expert operators and widely applied in rabbit experiments for various research purposes requiring exposure of the ON.
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Affiliation(s)
- Xiaoliang Li
- Department of Biomedical Engineering, School of Life Science and Technology, Shanghai Jiao Tong University, Shanghai, China
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Dose-related changes in retinal function and PKC-alpha expression in rabbits on vigabatrin medication. Graefes Arch Clin Exp Ophthalmol 2009; 247:1057-67. [DOI: 10.1007/s00417-009-1093-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 04/13/2009] [Indexed: 10/20/2022] Open
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Wallentén KG, Malmsjö M, Andréasson S, Wackenfors A, Johansson K, Ghosh F. Retinal function and PKC alpha expression after focal laser photocoagulation. Graefes Arch Clin Exp Ophthalmol 2007; 245:1815-24. [PMID: 17639452 DOI: 10.1007/s00417-007-0646-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 06/18/2007] [Accepted: 06/23/2007] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To examine the effects of focal laser photocoagulation on general and local retinal function and to relate electrophysiological findings with changes in protein kinase C (PKC) alpha expression. METHODS Twelve rabbits were treated with 70 spots of laser photocoagulation in the central cone-rich retina. The operated eyes were investigated with electroretinography (full-field ERG and multifocal electroretinography, mfERG) preoperatively and at 1, 3, and 5 weeks after surgery. The expression of PKC alpha was examined at all three time points using immunohistochemistry, and PKC alpha mRNA levels were quantified using real-time polymerase chain reaction (PCR). Immunohistochemistry for glial fibrillary acidic protein (GFAP) and hematoxylin and eosin staining was employed to monitor the extent and dynamics of the morphological response. RESULTS The full-field ERG revealed a significant increase in b-wave amplitudes derived from the isolated rod response (blue light) at all three time points after surgery (p < 0.05). Supernormal b-wave amplitudes were also found for the combined rod-cone response at 3 weeks (white light), and for the isolated cone response (light-adapted 30-Hz flicker) at 5 weeks after treatment. In the mfERG, amplitudes derived from the central retina did not change postoperatively, while the implicit time was significantly increased at all time points. Immunohistochemistry for PKC alpha revealed a reduced expression of the enzyme in rod bipolar cells 1 and 3 weeks after laser treatment compared with untreated controls. Five weeks postoperatively, no PKC alpha labeling in rod bipolar cells was found in any part of the retina. Real-time PCR 1 and 3 weeks after treatment displayed a decreased level of PKC alpha mRNA compared to the controls. Immunolabeled tissue sections from laser-treated eyes displayed GFAP expression in Müller cells in the treated as well as untreated retina 1 week postoperatively. At 3 and 5 weeks, GFAP labeling was less pronounced and was concentrated around the laser-treated spots. CONCLUSIONS Focal laser treatment in the rabbit eye induces local and wide-spread alterations in both rod- and cone-mediated retinal function in the form of supernormal b-wave amplitudes in the full-field ERG and increased latency in the mfERG. The electrophysiological abnormalities are accompanied by a progressive down-regulation of the PKC alpha isoenzyme in rod bipolar cells, reaching far beyond the treated area. PKC alpha is down-regulated directly by impaired protein synthesis, and also possibly indirectly by protein consumption related to GFAP up-regulation. The results indicate that focal laser photocoagulation interferes with PKC-alpha-mediated inhibitory regulation of inner retinal signal transmission.
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Keller RL, Hendrix DVH, Greenacre C. Shope fibroma virus keratitis and spontaneous cataracts in a domestic rabbit. Vet Ophthalmol 2007; 10:190-5. [PMID: 17445082 DOI: 10.1111/j.1463-5224.2007.00531.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A 7-year-old domestic rabbit presented for an enlarging ventral perilimbal mass OS. Keratectomy was performed to remove the mass. A diagnosis of Shope fibroma virus keratitis was confirmed based on signalment, clinical signs, histologic evaluation and virus isolation. Progression of bilateral cataracts leading to visual deficits was addressed with phacoemulsification. The rabbit remained visual and comfortable 5 months postoperatively and free of recurrence of the limbal mass 9 months after initial presentation.
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Affiliation(s)
- Rachel L Keller
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, C247 Veterinary Teaching Hospital, Knoxville, TN 37996-4544, USA.
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Kjellström U, Kjellström S, Bruun A, Andréasson S, Ponjavic V. Retinal function in rabbits does not improve 4-5 months after terminating treatment with vigabatrin. Doc Ophthalmol 2006; 112:35-41. [PMID: 16633724 DOI: 10.1007/s10633-006-0004-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE We have previously reported changes in retinal function and histopathology in rabbits treated with vigabatrin. The purpose of the present study was to evaluate retinal function and histopathology of retina in rabbits 4-5 months after terminating vigabatrin medication. METHODS Five rabbits were treated with a daily per oral dose of vigabatrin during 12-13 months. After terminating treatment an observation period of 4-5 months followed. Six rabbits receiving water served as controls. Standardized full-field electroretinograms were performed every 6-8 weeks, using a Burian-Allen bipolar contact lens. After 18 months the rabbits were sacrificed and the morphology of the sectioned retina was studied. The antibodies used for staining were GABA, GFAP, GAD, and vimentin. RESULTS After 12-13 months of treatment the full-field ERG was reduced in all rabbits treated with vigabatrin. There was a statistically significant difference in the dark adapted cone b-wave amplitude between treated animals and controls (Wilcoxon signed-rank test, p = 0.043). This difference was consistent also 4-5 months after terminating treatment. Immunohistology of the sectioned retina demonstrated no significant difference in immunoreactivity between treated animals and controls. All treated rabbits demonstrated elevated serum concentration of the drug during medication. CONCLUSION Four to five months after terminating treatment with vigabatrin the rabbit full-field ERG remains reduced in isolated cone b-wave amplitude indicating that vigabatrin induced retinal dysfunction may be irreversible. However, immunohistology is normal after a period without treatment, implying that the previously described changes in retinal morphology and glial cell activity are reversible, and probably exist only during treatment.
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Kjellström S, Bruun A, Isaksson B, Eriksson T, Andréasson S, Ponjavic V. Retinal function and histopathology in rabbits treated with Topiramate. Doc Ophthalmol 2006; 113:179-86. [PMID: 17111186 DOI: 10.1007/s10633-006-9027-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate retinal function and histopathology in rabbits treated orally with the anti-epileptic drug topiramate. METHODS Six rabbits were treated with a daily oral dose of topiramate during a period of eight months. Six rabbits receiving water served as controls. Blood samples were analyzed for determination of topiramate serum levels in order to ensure successful drug exposition. Standardized full-field electroretinograms (ERGs) were performed before treatment and then at 2, 3 and 8 months during the treatment period. After terminating treatment the rabbits were sacrificed and the morphology of the sectioned retina was studied. RESULTS After eight months of treatment the full-field ERG demonstrated normal rod function in treated and control rabbits, but the light adapted 30 Hz flicker b-wave amplitude was significantly reduced in the treated rabbits. This was the case for both the light adapted (Wilcoxon signed ranks test, P = 0.046) and the dark adapted (Wilcoxon signed ranks test, P = 0.028) 30 Hz flicker response from the treated rabbits. Retinal immunohistology revealed a severe accumulation of GABA in amacrine cells and in the inner plexiform layer in 4 of 6 treated rabbits compared to the controls. CONCLUSIONS Topiramate, orally administrated to rabbits, may cause a significant reduction of the retinal function demonstrated by the reduced b-wave amplitude in the full-field ERG, as well as changes in immunohistology characterized by a severe accumulation of GABA in the inner retina. The retinal dysfunction and the morphological changes indicate that topiramat may damage the retina, similarly to vigabatrin (another anti-epileptic drug).
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Affiliation(s)
- S Kjellström
- Department of Ophthalmology, University of Lund, S 221 85, Lund, Sweden
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