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Kramer RH. Suppressing Retinal Remodeling to Mitigate Vision Loss in Photoreceptor Degenerative Disorders. Annu Rev Vis Sci 2023; 9:131-153. [PMID: 37713276 DOI: 10.1146/annurev-vision-112122-020957] [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] [Indexed: 09/17/2023]
Abstract
Rod and cone photoreceptors degenerate in retinitis pigmentosa and age-related macular degeneration, robbing the visual system of light-triggered signals necessary for sight. However, changes in the retina do not stop with the photoreceptors. A stereotypical set of morphological and physiological changes, known as remodeling, occur in downstream retinal neurons. Some aspects of remodeling are homeostatic, with structural or functional changes compensating for partial loss of visual inputs. However, other aspects are nonhomeostatic, corrupting retinal information processing to obscure vision mediated naturally by surviving photoreceptors or artificially by vision-restoration technologies. In this review, I consider the mechanism of remodeling and its consequences for residual and restored visual function; discuss the role of retinoic acid, a critical molecular trigger of detrimental remodeling; and discuss strategies for suppressing retinoic acid biosynthesis or signaling as therapeutic possibilities for mitigating vision loss.
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Affiliation(s)
- Richard H Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, USA;
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2
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Mamtani NH, Mamtani HG, Chaturvedi SK. Psychiatric aspects of ophthalmic disorders: A narrative review. Indian J Ophthalmol 2023; 71:1810-1815. [PMID: 37203034 PMCID: PMC10391518 DOI: 10.4103/ijo.ijo_2101_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Ophthalmic disorders have psychiatric aspects associated with them at various levels. Psychological factors have a well-documented role in the causation, aggravation, and maintenance of various ophthalmic conditions, including glaucoma, central serous retinopathy, dry eye disease, and retinitis pigmentosa. Many ophthalmic conditions, including blindness, have psychological manifestations as well, which need to be addressed, in addition to the ophthalmic pathology. There is also significant overlap in the treatment of the two disciplines in many ways. For instance, many ophthalmic drugs have psychiatric side effects. Even ophthalmological surgeries have psychiatric aspects associated with them, which primarily include black patch psychosis and anxiety in the operation theater. This review will be useful for psychiatrists and ophthalmologists, for their clinical practice and research. Future research should focus on this interface to give it its well-deserved attention.
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Affiliation(s)
- Nidhi H Mamtani
- Department of Glaucoma, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Harkishan Gurmukh Mamtani
- Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Santosh K Chaturvedi
- Department of Psychiatry, Leicestershire Partnership, NHS Trust, Leicester, United Kingdom
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3
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Nguyen XTA, Moekotte L, Plomp AS, Bergen AA, van Genderen MM, Boon CJF. Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies. Int J Mol Sci 2023; 24:ijms24087481. [PMID: 37108642 PMCID: PMC10139437 DOI: 10.3390/ijms24087481] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/01/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Retinitis pigmentosa (RP) comprises a group of inherited retinal dystrophies characterized by the degeneration of rod photoreceptors, followed by the degeneration of cone photoreceptors. As a result of photoreceptor degeneration, affected individuals experience gradual loss of visual function, with primary symptoms of progressive nyctalopia, constricted visual fields and, ultimately, central vision loss. The onset, severity and clinical course of RP shows great variability and unpredictability, with most patients already experiencing some degree of visual disability in childhood. While RP is currently untreatable for the majority of patients, significant efforts have been made in the development of genetic therapies, which offer new hope for treatment for patients affected by inherited retinal dystrophies. In this exciting era of emerging gene therapies, it remains imperative to continue supporting patients with RP using all available options to manage their condition. Patients with RP experience a wide variety of physical, mental and social-emotional difficulties during their lifetime, of which some require timely intervention. This review aims to familiarize readers with clinical management options that are currently available for patients with RP.
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Affiliation(s)
- Xuan-Thanh-An Nguyen
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Lude Moekotte
- Department of Ophthalmology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Astrid S Plomp
- Department of Clinical Genetics, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Arthur A Bergen
- Department of Clinical Genetics, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Maria M van Genderen
- Department of Ophthalmology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Bartiméus, Diagnostic Center for Complex Visual Disorders, 3703 AJ Zeist, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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4
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Ahn J, Cha S, Choi KE, Kim SW, Yoo Y, Goo YS. Correlated Activity in the Degenerate Retina Inhibits Focal Response to Electrical Stimulation. Front Cell Neurosci 2022; 16:889663. [PMID: 35602554 PMCID: PMC9114441 DOI: 10.3389/fncel.2022.889663] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/13/2022] [Indexed: 11/24/2022] Open
Abstract
Retinal prostheses have shown some clinical success in patients with retinitis pigmentosa and age-related macular degeneration. However, even after the implantation of a retinal prosthesis, the patient’s visual acuity is at best less than 20/420. Reduced visual acuity may be explained by a decrease in the signal-to-noise ratio due to the spontaneous hyperactivity of retinal ganglion cells (RGCs) found in degenerate retinas. Unfortunately, abnormal retinal rewiring, commonly observed in degenerate retinas, has rarely been considered for the development of retinal prostheses. The purpose of this study was to investigate the aberrant retinal network response to electrical stimulation in terms of the spatial distribution of the electrically evoked RGC population. An 8 × 8 multielectrode array was used to measure the spiking activity of the RGC population. RGC spikes were recorded in wild-type [C57BL/6J; P56 (postnatal day 56)], rd1 (P56), rd10 (P14 and P56) mice, and macaque [wild-type and drug-induced retinal degeneration (RD) model] retinas. First, we performed a spike correlation analysis between RGCs to determine RGC connectivity. No correlation was observed between RGCs in the control group, including wild-type mice, rd10 P14 mice, and wild-type macaque retinas. In contrast, for the RD group, including rd1, rd10 P56, and RD macaque retinas, RGCs, up to approximately 400–600 μm apart, were significantly correlated. Moreover, to investigate the RGC population response to electrical stimulation, the number of electrically evoked RGC spikes was measured as a function of the distance between the stimulation and recording electrodes. With an increase in the interelectrode distance, the number of electrically evoked RGC spikes decreased exponentially in the control group. In contrast, electrically evoked RGC spikes were observed throughout the retina in the RD group, regardless of the inter-electrode distance. Taken together, in the degenerate retina, a more strongly coupled retinal network resulted in the widespread distribution of electrically evoked RGC spikes. This finding could explain the low-resolution vision in prosthesis-implanted patients.
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Affiliation(s)
- Jungryul Ahn
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, South Korea
| | - Seongkwang Cha
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, South Korea
| | - Kwang-Eon Choi
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Seong-Woo Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
- *Correspondence: Seong-Woo Kim,
| | - Yongseok Yoo
- Department of Electronics Engineering, Incheon National University, Incheon, South Korea
- Yongseok Yoo,
| | - Yong Sook Goo
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, South Korea
- Yong Sook Goo,
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5
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Telias M, Sit KK, Frozenfar D, Smith B, Misra A, Goard MJ, Kramer RH. Retinoic acid inhibitors mitigate vision loss in a mouse model of retinal degeneration. SCIENCE ADVANCES 2022; 8:eabm4643. [PMID: 35302843 PMCID: PMC8932665 DOI: 10.1126/sciadv.abm4643] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Rod and cone photoreceptors degenerate in retinitis pigmentosa (RP). While downstream neurons survive, they undergo physiological changes, including accelerated spontaneous firing in retinal ganglion cells (RGCs). Retinoic acid (RA) is the molecular trigger of RGC hyperactivity, but whether this interferes with visual perception is unknown. Here, we show that inhibiting RA synthesis with disulfiram, a deterrent of human alcohol abuse, improves behavioral image detection in vision-impaired mice. In vivo Ca2+ imaging shows that disulfiram sharpens orientation tuning of visual cortical neurons and strengthens fidelity of responses to natural scenes. An RA receptor inhibitor also reduces RGC hyperactivity, sharpens cortical representations, and improves image detection. These findings suggest that photoreceptor degeneration is not the only cause of vision loss in RP. RA-induced corruption of retinal information processing also degrades vision, pointing to RA synthesis and signaling inhibitors as potential therapeutic tools for improving sight in RP and other retinal degenerative disorders.
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Affiliation(s)
- Michael Telias
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Kevin K. Sit
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Daniel Frozenfar
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Benjamin Smith
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Arjit Misra
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA
| | - Michael J. Goard
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Richard H. Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
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Christelle M, Lise M, Ben M'Barek K. Challenges of cell therapies for retinal diseases. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 166:49-77. [DOI: 10.1016/bs.irn.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Jones L, Moosajee M. Visual hallucinations and sight loss in children and young adults: a retrospective case series of Charles Bonnet syndrome. Br J Ophthalmol 2021; 105:1604-1609. [PMID: 32933935 PMCID: PMC8543192 DOI: 10.1136/bjophthalmol-2020-317237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/06/2020] [Accepted: 08/27/2020] [Indexed: 12/02/2022]
Abstract
BACKGROUND/AIMS Charles Bonnet syndrome (CBS) is a complication of sight loss affecting all ages; yet, few childhood cases have been reported. Our aim is to raise awareness of this under-reported association occurring in children and young adults in order to prevent psychological harm in this age group. METHODS A retrospective case series reviewing medical notes of patients <25 years of age with sight loss and reported CBS at a single centre hospital eye service in London, United Kingdom. Search of electronic patient records identified 13 patients experiencing hallucinatory events over a 9-year period. Outcomes were patient demographics including ocular diagnosis, visual acuity at time of onset, characteristics of hallucinations, clinical management strategies and patient-reported affliction. RESULTS Eight patients were diagnosed with progressive inherited retinal diseases, primarily Stargardt disease (N=5). Clinical history indicated patients had significantly reduced best-corrected visual acuity (BCVA) in at least one eye at onset; median (IQR) worse eye BCVA was 1.0 (0.86-1.6) logarithm of minimum angle of resolution(LogMAR). CBS significantly affected patients' personal lives including education, diet and sleep. Clinical management was varied, mostly relating to reassurance at the point of contact. CONCLUSION We describe the clinical features of young patients with CBS, with management strategies and aspects of negative outcomes. High potential caseload and risk of psychological harm merit further research. Increased awareness among healthcare professionals and patient education to forewarn susceptible individuals may reduce the overall impact and improve coping with symptoms.
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Affiliation(s)
- Lee Jones
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Institute of Ophthalmology, University College London, London, UK
| | - Mariya Moosajee
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Institute of Ophthalmology, University College London, London, UK
- Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK
- The Francis Crick Institute, London, UK
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8
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Fernández E, Alfaro A, Soto-Sánchez C, González-López P, Lozano Ortega AM, Peña S, Grima MD, Rodil A, Gómez B, Chen X, Roelfsema PR, Rolston JD, Davis TS, Normann RA. Visual percepts evoked with an Intracortical 96-channel microelectrode array inserted in human occipital cortex. J Clin Invest 2021; 131:151331. [PMID: 34665780 DOI: 10.1172/jci151331] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 09/28/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND A long-held dream of scientists is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight. However, no clinically available cortical visual prosthesis yet exists. METHODS We implanted an intracortical microelectrode array consisting of 96 electrodes in the visual cortex of a 57-year-old person with complete blindness for a six- month period. We measured thresholds and the characteristics of the visual percepts elicited by intracortical microstimulation. RESULTS Implantation and subsequent explantation of intracortical microelectrodes were carried out without complications. The mean stimulation threshold for single electrodes was 66.8 ± 36.5 μA. We consistently obtained high-quality recordings from visually deprived neurons and the stimulation parameters remained stable over time. Simultaneous stimulation via multiple electrodes were associated with a significant reduction in thresholds (p<0.001, ANOVA test) and evoked discriminable phosphene percepts, allowing the blind participant to identify some letters and recognize object boundaries. Furthermore, we observed a learning process that helped the subject to recognize complex patterns over time. CONCLUSIONS Our results demonstrate the safety and efficacy of chronic intracortical microstimulation via a large number of electrodes in human visual cortex, showing its high potential for restoring functional vision in the blind. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT02983370. FUNDING Funding was provided by grant RTI2018-098969-B-100 from the Spanish Ministerio de Ciencia Innovación y Universidades, by grant PROMETEO/2019/119 from the Generalitat Valenciana (Spain), by the Bidons Egara Research Chair of the University Miguel Hernández (Spain) and by the John Moran Eye Center of the University of Utah (US).
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Affiliation(s)
| | - Arantxa Alfaro
- Servicio de Neurología, Hospital Vega Baja, Elche, Spain
| | | | - Pablo González-López
- Servicio de Neurología, Hospital General Universitario de Alicante, Alicante, Spain
| | | | - Sebastian Peña
- Bioengineering Institute, University Miguel Hernandez, Elche, Spain
| | | | - Alfonso Rodil
- Bioengineering Institute, University Miguel Hernandez, Elche, Spain
| | - Bernardeta Gómez
- Bioengineering Institute, University Miguel Hernandez, Elche, Spain
| | - Xing Chen
- Department of Vision & Cognition, Netherland Institute for Neuroscience, Amsterdam, Netherlands
| | - Pieter R Roelfsema
- Department of Vision & Cognition, Netherland Institute for Neuroscience, Amsterdam, Netherlands
| | - John D Rolston
- Department of Neurosurgery and Biomedical Engineering, University of Utah, Salt Lake City, United States of America
| | - Tyler S Davis
- Department of Neurosurgery and Biomedical Engineering, University of Utah, Salt Lake City, United States of America
| | - Richard A Normann
- John Moran Eye Center and Biomedical Engineering, University of Utah, Salt Lake City, United States of America
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Lu Y, Sun X. Retinitis pigmentosa sine pigmento masqueraded as myopia: A case report (CARE). Medicine (Baltimore) 2021; 100:e24006. [PMID: 33545995 PMCID: PMC7837948 DOI: 10.1097/md.0000000000024006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 12/03/2020] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION Retinitis pigmentosa is a major cause of visual disability and blindness. Photopsia is usually presented in patients with retinal traction caused by posterior vitreous detachment in clinic, which would occur more commonly in those suffer from moderate or high myopia. We describe a patient with leopard-like retinopathy initially complaining of photopsia caused not by myopia but by retinitis pigmentosa. PATIENT CONCERNS A 39-year-old woman with a history of moderate myopia presented to us complaining of photopsia for several days. DIAGNOSIS Fundus examination revealed leopard-like retinopathy with normal optic disc and macula appearance in both eyes. The atrophy of retinal pigment epithelium was found in peripheral retina while no bone spicule was present. Retinal multimodal imaging helped in the correct diagnosis of retinitis pigmentosa (sine pigmento), later confirmed by genetic testing. INTERVENTIONS At current no specific treatment was applied, but the patient was required for follow-up observation every six months. OUTCOMES Follow-up observation. CONCLUSION This case highlights the potential for retinitis pigmentosa sine pigmento to present with photopsia under cover of myopia and the importance of performing multimodal imaging including fundus autofluorescence for fundus disorders. Careful history review and multimodal imaging with genetic testing would help for the correct diagnosis of retinitis pigmentosa sine pigmento.
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Affiliation(s)
- Yi Lu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai JiaoTong University
- Shanghai Key Laboratory of Ocular Fundus Disease
- Shanghai Engineering Center for Visual Science and Photomedicine
- National Clinical Research Center for Eye Diseases
- Shanghai Engineering Center of Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai JiaoTong University
- Shanghai Key Laboratory of Ocular Fundus Disease
- Shanghai Engineering Center for Visual Science and Photomedicine
- National Clinical Research Center for Eye Diseases
- Shanghai Engineering Center of Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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10
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Gehlen J, Esser S, Schaffrath K, Johnen S, Walter P, Müller F. Blockade of Retinal Oscillations by Benzodiazepines Improves Efficiency of Electrical Stimulation in the Mouse Model of RP, rd10. Invest Ophthalmol Vis Sci 2020; 61:37. [PMID: 33252632 PMCID: PMC7705397 DOI: 10.1167/iovs.61.13.37] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Purpose In RP, photoreceptors degenerate. Retinal prostheses are considered a suitable strategy to restore vision. In animal models of RP, a pathologic rhythmic activity seems to compromise the efficiency of retinal ganglion cell stimulation by an electrical prosthesis. We, therefore, strove to eliminate this pathologic activity. Methods Electrophysiologic recordings of local field potentials and spike activity of retinal ganglion cells were obtained in vitro from retinae of wild-type and rd10 mice using multielectrode arrays. Retinae were stimulated electrically. Results The efficiency of electrical stimulation was lower in rd10 retina than in wild-type retina and this was highly correlated with the presence of oscillations in retinal activity. Glycine and GABA, as well as the benzodiazepines diazepam, lorazepam, and flunitrazepam, abolished retinal oscillations and, most important, increased the efficiency of electrical stimulation to values similar to those in wild-type retina. Conclusions Treatment of patients with these benzodiazepines may offer a way to improve the performance of retinal implants in cases with poor implant proficiency. This study may open the way to a therapy that supports electrical stimulation by prostheses with pharmacologic treatment.
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Affiliation(s)
- Jana Gehlen
- Institute of Biological Information Processing, Molecular and Cellular Physiology, IBI-1, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Stefan Esser
- Institute of Biological Information Processing, Molecular and Cellular Physiology, IBI-1, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Kim Schaffrath
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Sandra Johnen
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Peter Walter
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Frank Müller
- Institute of Biological Information Processing, Molecular and Cellular Physiology, IBI-1, Forschungszentrum Jülich GmbH, Jülich, Germany
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11
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Morizur L, Herardot E, Monville C, Ben M'Barek K. Human pluripotent stem cells: A toolbox to understand and treat retinal degeneration. Mol Cell Neurosci 2020; 107:103523. [PMID: 32634576 DOI: 10.1016/j.mcn.2020.103523] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/24/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022] Open
Abstract
Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP) are retinal degenerative disorders that dramatically damage the retina. As there is no therapeutic option for the majority of patients, vision is progressively and irremediably lost. Owing to their unlimited renewal and potency to give rise to any cell type of the human adult body, human pluripotent stem cells (hPSCs) have been extensively studied in recent years to develop more physiologically relevant in vitro cellular models. Such models open new perspectives to investigate the pathological molecular mechanisms of AMD and RP but also in drug screening. Moreover, proof-of-concept of hPSC-derived retinal cell therapy in animal models have led to first clinical trials. This review outlines the recent advances in the use of hPSCs in pathological modeling of retinal degeneration and their use in regenerative medicine. We also address the associated limitations and challenges that need to be overcome when using hPSCs.
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Affiliation(s)
- Lise Morizur
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100 Corbeil-Essonnes, France; Université Paris-Saclay, Université d'Evry, U861, 91100 Corbeil-Essonnes, France; Centre d'Etude des Cellules Souches, 91100 Corbeil-Essonnes, France
| | - Elise Herardot
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100 Corbeil-Essonnes, France; Université Paris-Saclay, Université d'Evry, U861, 91100 Corbeil-Essonnes, France
| | - Christelle Monville
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100 Corbeil-Essonnes, France; Université Paris-Saclay, Université d'Evry, U861, 91100 Corbeil-Essonnes, France.
| | - Karim Ben M'Barek
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100 Corbeil-Essonnes, France; Université Paris-Saclay, Université d'Evry, U861, 91100 Corbeil-Essonnes, France; Centre d'Etude des Cellules Souches, 91100 Corbeil-Essonnes, France.
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12
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Errera M, Robson AG, Wong T, Hykin PG, Pal B, Sagoo MS, Pavesio CE, Moore AT, Webster AR, MacLaren RE, Holder GE. Unilateral pigmentary retinopathy: a retrospective case series. Acta Ophthalmol 2019; 97:e601-e617. [PMID: 30597758 DOI: 10.1111/aos.13981] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 11/01/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE To review the clinical characteristics and address the aetiology in a group of patients presenting with unilateral retinal pigmentary changes, best described as unilateral pigmentary retinopathy (UPR). METHODS The cohort of 42 patients was identified retrospectively from the Moorfields Eye Hospital electrophysiology database. All had undergone full-field [electroretinography (ERG)] and pattern electroretinography (PERG), with 13 additionally having multifocal ERG (mfERG). The clinical findings, fundus photographs and fundus autofluorescence (AF) images were reviewed. RESULTS All index eyes showed ERG evidence of generalized photoreceptor dysfunction with most showing a similar degree of rod and cone involvement. However, although the fellow eyes all had a normal fundus examination, there were bilateral but asymmetrical ERG abnormalities in eight patients and a further four patients had PERG evidence of macular dysfunction in the fellow eye. A relevant medical history or the diagnosis of an ophthalmologic entity that might be related to the unilateral fundus changes was ascertained in 15 cases (~36%) including acute zonal occult outer retinopathy, trauma, systemic malignancy or autoimmune disease, retinal vasculitis, presumed pregnancy-related choroidal ischaemia and meningitis. Two patients had a family history of retinitis pigmentosa (RP; 4.8%). CONCLUSION The underlying aetiology in most cases of UPR cannot accurately be identified, but an heritable cause is unlikely. Aspects of the history clearly suggest an acquired disorder in some patients. Twenty-five patients (60%) with nongenetic UPR did not adhere to the pattern of rod greater than cone dysfunction that occurs in RP (rod-cone dystrophy), and the pattern of rod > cone dysfunction seen in true RP is thus not a feature of most patients with UPR.
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Affiliation(s)
- Marie‐Hélène Errera
- Moorfields Eye Hospital London UK
- Quinze‐Vingts National Ophthalmology Hospital DHU Sight Restore. CIC 1423 Sorbonne‐Universités UPMC Université ParisFrance
| | - Anthony G. Robson
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | | | - Philip G. Hykin
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Bishwanath Pal
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Mandeep S. Sagoo
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Carlos E. Pavesio
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Anthony T. Moore
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Andrew R. Webster
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
| | - Robert E. MacLaren
- Oxford University Hospitals NHS Foundation Trust UK. Nuffield Department of Clinical Neurosciences John Radcliffe Hospital Oxford UK
| | - Graham E. Holder
- Moorfields Eye Hospital London UK
- Institute of Ophthalmology University College London UK
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13
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Stasheff SF. Clinical Impact of Spontaneous Hyperactivity in Degenerating Retinas: Significance for Diagnosis, Symptoms, and Treatment. Front Cell Neurosci 2018; 12:298. [PMID: 30250425 PMCID: PMC6139326 DOI: 10.3389/fncel.2018.00298] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 08/17/2018] [Indexed: 11/23/2022] Open
Abstract
Hereditary retinal degenerations result from varied pathophysiologic mechanisms, all ultimately characterized by photoreceptor dysfunction and death. Hence, much research on these diseases has concentrated on the outer retina. Over the past decade or so increasing attention has focused on concomitant changes in complex inner retinal neural circuits that process visual signals for transmission to the brain. One striking abnormality develops before the ultimately profound anatomic disruption of the inner retina. Highly elevated spontaneous activity was first demonstrated in central nervous system visual centers in vivo by Dräger and Hubel (1978), and subsequently has been confirmed in vitro, now in multiple animal models and by multiple investigators (see other contributions to this Research Topic). What evidence exists that this phenomenon occurs in human patients with retinal degeneration, and what is the ultimate effect of spontaneous hyperactivity in the output neurons, the retinal ganglion cells? Here I summarize abnormalities of visual perception among patients with retinal degeneration that may arise from hyperactivity. Next, I consider the disruption of neural encoding and anatomic connectivity that may result within the retina and in downstream visual centers of the brain. I then consider how specific characteristics of hyperactivity may distinguish various forms or stages of retinal degeneration, potentially helping in the near future to refine diagnosis and/or treatment choices for different patients. Finally, I review how consideration of these features may help optimize pharmacologic, gene, stem cell, prosthetic or other therapies to forestall visual loss or restore sight.
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Affiliation(s)
- Steven F Stasheff
- Center for Neuroscience and Behavioral Medicine, Gilbert Family Neurofibromatosis Institute, Children's National Health System, Washington, DC, United States.,Visual Neurophysiology, Neuro-ophthalmology and Pediatric Neurology, Retinal Neurophysiology Section, National Eye Institute, Bethesda, MD, United States
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Verbakel SK, van Huet RAC, Boon CJF, den Hollander AI, Collin RWJ, Klaver CCW, Hoyng CB, Roepman R, Klevering BJ. Non-syndromic retinitis pigmentosa. Prog Retin Eye Res 2018; 66:157-186. [PMID: 29597005 DOI: 10.1016/j.preteyeres.2018.03.005] [Citation(s) in RCA: 492] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 12/23/2022]
Abstract
Retinitis pigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized by the primary degeneration of rod and cone photoreceptors. RP is a leading cause of visual disability, with a worldwide prevalence of 1:4000. Although the majority of RP cases are non-syndromic, 20-30% of patients with RP also have an associated non-ocular condition. RP typically manifests with night blindness in adolescence, followed by concentric visual field loss, reflecting the principal dysfunction of rod photoreceptors; central vision loss occurs later in life due to cone dysfunction. Photoreceptor function measured with an electroretinogram is markedly reduced or even absent. Optical coherence tomography (OCT) and fundus autofluorescence (FAF) imaging show a progressive loss of outer retinal layers and altered lipofuscin distribution in a characteristic pattern. Over the past three decades, a vast number of disease-causing variants in more than 80 genes have been associated with non-syndromic RP. The wide heterogeneity of RP makes it challenging to describe the clinical findings and pathogenesis. In this review, we provide a comprehensive overview of the clinical characteristics of RP specific to genetically defined patient subsets. We supply a unique atlas with color fundus photographs of most RP subtypes, and we discuss the relevant considerations with respect to differential diagnoses. In addition, we discuss the genes involved in the pathogenesis of RP, as well as the retinal processes that are affected by pathogenic mutations in these genes. Finally, we review management strategies for patients with RP, including counseling, visual rehabilitation, and current and emerging therapeutic options.
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Affiliation(s)
- Sanne K Verbakel
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ramon A C van Huet
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands; Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - B Jeroen Klevering
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
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15
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Haselier C, Biswas S, Rösch S, Thumann G, Müller F, Walter P. Correlations between specific patterns of spontaneous activity and stimulation efficiency in degenerated retina. PLoS One 2017; 12:e0190048. [PMID: 29281713 PMCID: PMC5744965 DOI: 10.1371/journal.pone.0190048] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/07/2017] [Indexed: 11/20/2022] Open
Abstract
Retinal prostheses that are currently used to restore vision in patients suffering from retinal degeneration are not adjusted to the changes occurring during the remodeling process of the retina. Recent studies revealed abnormal rhythmic activity in the retina of genetic mouse models of retinitis pigmentosa. Here we describe this abnormal activity also in a pharmacologically-induced (MNU) mouse model of retinal degeneration. To investigate how this abnormal activity affects the excitability of retinal ganglion cells, we recorded the electrical activity from whole mounted retinas of rd10 mice and MNU-treated mice using a microelectrode array system and applied biphasic current pulses of different amplitude and duration to stimulate ganglion cells electrically. We show that the electrical stimulation efficiency is strongly reduced in degenerated retinas, in particular when abnormal activity such as oscillations and rhythmic firing of bursts of action potentials can be observed. Using a prestimulus pulse sequence, we could abolish rhythmic retinal activity. Under these conditions, the stimulation efficiency was enhanced in a few cases but not in the majority of tested cells. Nevertheless, this approach supports the idea that modified stimulation protocols could help to improve the efficiency of retinal prostheses in the future.
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Affiliation(s)
| | - Sonia Biswas
- Institute of Complex Systems, Cellular Biophysics, ICS-4, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Sarah Rösch
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Gabriele Thumann
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Frank Müller
- Institute of Complex Systems, Cellular Biophysics, ICS-4, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Peter Walter
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
- * E-mail:
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Serrano-Aguilar P, Trujillo-Martin MM, del Pino-Sedeño T, Pérez de la Rosa A, de Pascual y Medina AM, Perestelo-Pérez L, Toledo-Chávarri A, Posada de la Paz M, Sarría Santamera A. Patient participation in the development of a clinical guideline for inherited retinal dystrophies. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2016.1182907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- P. Serrano-Aguilar
- Evaluation Service of the Canary Islands Health Service (SESCS), Santa Cruz de Tenerife, Spain
- Spanish Network of Health Services Research for Chronic Diseases (REDISSEC), Madrid, Spain
- Centre for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Canary Islands, Spain
| | - M. M. Trujillo-Martin
- Spanish Network of Health Services Research for Chronic Diseases (REDISSEC), Madrid, Spain
- Centre for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Canary Islands, Spain
- Canary Foundation for Health Care Research (FUNCANIS), Canary Islands, Spain
| | - T. del Pino-Sedeño
- Canarian Foundation for Advances in Biomedicine and Biotechnology (BIOAVANCE), Canary Islands, Spain
| | - A. Pérez de la Rosa
- Canary Foundation for Health Care Research (FUNCANIS), Canary Islands, Spain
| | | | - L. Perestelo-Pérez
- Evaluation Service of the Canary Islands Health Service (SESCS), Santa Cruz de Tenerife, Spain
- Spanish Network of Health Services Research for Chronic Diseases (REDISSEC), Madrid, Spain
- Centre for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Canary Islands, Spain
| | - A. Toledo-Chávarri
- Canary Foundation for Health Care Research (FUNCANIS), Canary Islands, Spain
| | - M. Posada de la Paz
- The Institute of Rare Diseases Research, The Institute of Health Carlos III. Ministry of Economy and Competitiveness, Madrid, Spain
| | - A. Sarría Santamera
- Spanish Network of Health Services Research for Chronic Diseases (REDISSEC), Madrid, Spain
- Health Technology Assessment Agency, The Institute of Health Carlos III. Ministry of Economy and Competitiveness, Madrid, Spain
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Krishnamoorthy V, Cherukuri P, Poria D, Goel M, Dagar S, Dhingra NK. Retinal Remodeling: Concerns, Emerging Remedies and Future Prospects. Front Cell Neurosci 2016; 10:38. [PMID: 26924962 PMCID: PMC4756099 DOI: 10.3389/fncel.2016.00038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 02/01/2016] [Indexed: 12/21/2022] Open
Abstract
Deafferentation results not only in sensory loss, but also in a variety of alterations in the postsynaptic circuitry. These alterations may have detrimental impact on potential treatment strategies. Progressive loss of photoreceptors in retinal degenerative diseases, such as retinitis pigmentosa and age-related macular degeneration, leads to several changes in the remnant retinal circuitry. Müller glial cells undergo hypertrophy and form a glial seal. The second- and third-order retinal neurons undergo morphological, biochemical and physiological alterations. A result of these alterations is that retinal ganglion cells (RGCs), the output neurons of the retina, become hyperactive and exhibit spontaneous, oscillatory bursts of spikes. This aberrant electrical activity degrades the signal-to-noise ratio in RGC responses, and thus the quality of information they transmit to the brain. These changes in the remnant retina, collectively termed “retinal remodeling”, pose challenges for genetic, cellular and bionic approaches to restore vision. It is therefore crucial to understand the nature of retinal remodeling, how it affects the ability of remnant retina to respond to novel therapeutic strategies, and how to ameliorate its effects. In this article, we discuss these topics, and suggest that the pathological state of the retinal output following photoreceptor loss is reversible, and therefore, amenable to restorative strategies.
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Affiliation(s)
| | - Pitchaiah Cherukuri
- Developmental Neurobiology Laboratory, European Neuroscience Institute Göttingen Göttingen, Germany
| | - Deepak Poria
- National Brain Research Centre Manesar, Haryana, India
| | - Manvi Goel
- National Brain Research Centre Manesar, Haryana, India
| | - Sushma Dagar
- Institute of Neuro- and Sensory Physiology, Heinrich-Heine University Düsseldorf, Germany
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18
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Scarinci F, Sheyman AT, Jampol LM. CENTRAL VISUAL PHENOMENA AS CLUES TO VITREOMACULAR TRACTION IN PATIENTS WITH NORMAL FUNDUS OCULI. Retin Cases Brief Rep 2015; 10:361-3. [PMID: 26674273 DOI: 10.1097/icb.0000000000000263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To report two cases where the primary visual complaints were central visual phenomena, with normal fundus biomicroscopy. METHODS History and clinical examination, fundus autofluorescence, and spectral domain-optical coherence tomography. RESULTS The authors report 2 patients, a 66-year-old woman and a 77-year-old woman, who complained of a central visual disturbance in one eye. Best-corrected visual acuity was normal. Ophthalmoscopy in the first case was unremarkable and showed minimal retinal pigment epithelial mottling in Case 2. Spectral domain-optical coherence tomography revealed vitreomacular traction with foveal distortion in both eyes, associated with small cysts in the inner retinal layers and in one patient disruption of photoreceptors. CONCLUSION Central visual phenomena are important clues for central vitreomacular traction, even in the presence of a normal fundus examination. The authors highlight the importance of performing spectral domain-optical coherence tomography evaluation in this setting before considering neurologic or systemic causes.
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Affiliation(s)
- Fabio Scarinci
- *Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and †G.B. Bietti Eye Foundation-IRCCS, Rome, Italy
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Kalloniatis M, Nivison-Smith L, Chua J, Acosta ML, Fletcher EL. Using the rd1 mouse to understand functional and anatomical retinal remodelling and treatment implications in retinitis pigmentosa: A review. Exp Eye Res 2015; 150:106-21. [PMID: 26521764 DOI: 10.1016/j.exer.2015.10.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/31/2022]
Abstract
Retinitis Pigmentosa (RP) reflects a range of inherited retinal disorders which involve photoreceptor degeneration and retinal pigmented epithelium dysfunction. Despite the multitude of genetic mutations being associated with the RP phenotype, the clinical and functional manifestations of the disease remain the same: nyctalopia, visual field constriction (tunnel vision), photopsias and pigment proliferation. In this review, we describe the typical clinical phenotype of human RP and review the anatomical and functional remodelling which occurs in RP determined from studies in the rd/rd (rd1) mouse. We also review studies that report a slowing down or show an acceleration of retinal degeneration and finally we provide insights on the impact retinal remodelling may have in vision restoration strategies.
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Affiliation(s)
- M Kalloniatis
- Centre for Eye Health, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia.
| | - L Nivison-Smith
- Centre for Eye Health, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia
| | - J Chua
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - M L Acosta
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - E L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia
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Poria D, Dhingra NK. Spontaneous oscillatory activity in rd1 mouse retina is transferred from ON pathway to OFF pathway via glycinergic synapse. J Neurophysiol 2014; 113:420-5. [PMID: 25355966 DOI: 10.1152/jn.00702.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Retinal ganglion cells (RGCs) spike randomly in the dark and carry information about visual stimuli to the brain via specific spike patterns. However, following photoreceptor loss, both ON and OFF type of RGCs exhibit spontaneous oscillatory spike activity, which reduces the quality of information they can carry. Furthermore, it is not clear how the oscillatory activity would interact with the experimental treatment approaches designed to produce artificial vision. The oscillatory activity is considered to originate in ON-cone bipolar cells, AII amacrine cells, and/or their synaptic interactions. However, it is unknown how the oscillatory activity is generated in OFF RGCs. We tested the hypothesis that oscillatory activity is transferred from the ON pathway to the OFF pathway via the glycinergic AII amacrine cells. Using extracellular loose-patch and whole cell patch recordings, we recorded oscillatory activity in ON and OFF RGCs and studied their response to strychnine, a specific glycine receptor blocker. The cells were labeled with a fluorescent dye, and their dendritic stratification in inner plexiform layer was studied using confocal microscopy. Application of strychnine resulted in abolition of the oscillatory burst activity in OFF RGCs but not in ON RGCs, implying that oscillatory activity is generated in ON pathway and is transferred to OFF pathway, likely via the glycinergic AII amacrine cells. We found oscillatory activity in RGCs as early as postnatal day 12 in rd1 mouse, when rod degeneration has started but cones are still intact. This suggests that the oscillatory activity in rd1 mouse retina originates in rod pathway.
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Affiliation(s)
- Deepak Poria
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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Haq W, Arango-Gonzalez B, Zrenner E, Euler T, Schubert T. Synaptic remodeling generates synchronous oscillations in the degenerated outer mouse retina. Front Neural Circuits 2014; 8:108. [PMID: 25249942 PMCID: PMC4155782 DOI: 10.3389/fncir.2014.00108] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/19/2014] [Indexed: 11/28/2022] Open
Abstract
During neuronal degenerative diseases, neuronal microcircuits undergo severe structural alterations, leading to remodeling of synaptic connectivity. The functional consequences of such remodeling are mostly unknown. For instance, in mutant rd1 mouse retina, a common model for Retinitis Pigmentosa, rod bipolar cells (RBCs) establish contacts with remnant cone photoreceptors (cones) as a consequence of rod photoreceptor cell death and the resulting lack of presynaptic input. To assess the functional connectivity in the remodeled, light-insensitive outer rd1 retina, we recorded spontaneous population activity in retinal wholemounts using Ca(2+) imaging and identified the participating cell types. Focusing on cones, RBCs and horizontal cells (HCs), we found that these cell types display spontaneous oscillatory activity and form synchronously active clusters. Overall activity was modulated by GABAergic inhibition from interneurons such as HCs and/or possibly interplexiform cells. Many of the activity clusters comprised both cones and RBCs. Opposite to what is expected from the intact (wild-type) cone-ON bipolar cell pathway, cone and RBC activity was positively correlated and, at least partially, mediated by glutamate transporters expressed on RBCs. Deletion of gap junctional coupling between cones reduced the number of clusters, indicating that electrical cone coupling plays a crucial role for generating the observed synchronized oscillations. In conclusion, degeneration-induced synaptic remodeling of the rd1 retina results in a complex self-sustained outer retinal oscillatory network, that complements (and potentially modulates) the recently described inner retinal oscillatory network consisting of amacrine, bipolar and ganglion cells.
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Affiliation(s)
- Wadood Haq
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of TübingenTübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, University of TübingenTübingen, Germany
| | - Blanca Arango-Gonzalez
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of TübingenTübingen, Germany
| | - Eberhart Zrenner
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of TübingenTübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, University of TübingenTübingen, Germany
| | - Thomas Euler
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of TübingenTübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, University of TübingenTübingen, Germany
| | - Timm Schubert
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of TübingenTübingen, Germany
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Rozanski C, Haythornthwaite JA, Dagnelie G, Bittner AK. Applying theories and interventions from behavioral medicine to understand and reduce visual field variability in patients with vision loss. Med Hypotheses 2014; 83:190-5. [PMID: 24854574 DOI: 10.1016/j.mehy.2014.04.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 03/21/2014] [Accepted: 04/06/2014] [Indexed: 11/18/2022]
Abstract
Visual field (VF) test results are often unreliable in visually impaired patients, but continue to be a cornerstone of clinical trials and play a vital role in clinical decision making since they are the primary method to determine patients' functional vision loss or progression. Currently, patients are typically asked to perform VF tasks with minimal instruction or consideration of their psychological experience during the test. The gradual loss of vision due to retinal diseases, such as retinitis pigmentosa (RP), age-related macular degeneration (AMD), or glaucoma can contribute to the experience of negative psychosocial states, such as anxiety, stress, and depression, as well as diminished quality of life. We hypothesize that VF testing elicits test performance anxiety and perception of functional losses of vision, which induces distracting negative thoughts that result in increased VF test variability. Resources for processing and responding to vision-related information may be diverted from task-relevant VF stimuli to task-irrelevant ones, such as internal worry and test anxiety, thereby resulting in VF test performance decrements. We present a theoretical model to support the hypothesis that VF variability is linked to patients' negative thoughts during VF testing. This conceptual framework provides a basis for the development of coping strategies and mindfulness-based interventions to be evaluated in future research aimed at improving psychosocial states and VF reliability in visually-impaired patients. It would be highly significant to intervene by modifying negative thoughts during VF testing to reduce test variability in glaucoma patients who are progressively losing vision to a blinding eye disease, but whose vision loss has not been accurately identified and treated early enough due to variable VF results. In clinical trials of potential interventions for RP and non-neovascular AMD, reducing VF variability would effectively increase the precision for detecting treatment effects and allow a reduction in the number of VF tests needed to estimate the treatment responses, thus reducing burden on investigators and patients, as well as saving time and money.
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Affiliation(s)
- Collin Rozanski
- Johns Hopkins University, 3400 N. Charles Street Baltimore, MD 21218, United States
| | | | - Gislin Dagnelie
- Johns Hopkins University, Dept. of Ophthalmology, Wilmer Eye Institute, United States
| | - Ava K Bittner
- Nova Southeastern University, College of Optometry, United States.
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fMRI of retina-originated phosphenes experienced by patients with Leber congenital amaurosis. PLoS One 2014; 9:e86068. [PMID: 24465873 PMCID: PMC3897613 DOI: 10.1371/journal.pone.0086068] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 12/05/2013] [Indexed: 11/19/2022] Open
Abstract
A phenomenon characterized by the experience of seeing light without any light actually entering the eye is called phosphenes or photopsias. Phosphenes can occur spontaneously or via induction by external stimuli. Previous reports regarding phosphenes have primarily focused on externally induced phosphenes such as by applying alternating or direct current to the cortex. A few of these reports used functional magnetic resonance (fMRI) to study activations induced by cortical phosphenes. However, there are no fMRI reports on spontaneous phosphenes originating from the retina and the resulting pattern of cortical activations. We performed fMRI during a reversing checkerboard paradigm in three LCA patients who underwent unilateral gene therapy and reported experiencing frequent phosphene on a daily basis. We observed bilateral cortical activation covering the entire visual cortices when patients reported experiencing phosphenes. In contrast, in the absence of phosphenes, activation was regulated by patient's visual ability and demonstrated improved cortical activation due to gene therapy. These fMRI results illustrate the potential impact of phosphene perception on visual function and they may explain some of the variability that clinicians find in visual function testing in retinal degeneration. Although we did not perform correlations between visual function and phosphenes, we hope data presented here raises awareness of this phenomenon and its potential effect on visual function and the implications for clinical testing. We recommend a thorough history for phosphene experiences be taken in patients with retinal disease who are candidates for gene or molecular therapy. Lastly, these data illustrate the potential power of fMRI as an outcome measure of gene therapy and the negative impact phosphenes may have on vision testing. fMRI has proven to be a sensitive, non-invasive, and reproducible test paradigm for these purposes and can complement standard visual function testing.
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Bittner AK, Haythornthwaite JA, Diener-West M, Dagnelie G. Photopsias are related in part to perceived stress and positive mood in retinitis pigmentosa. Eye (Lond) 2011; 26:101-8. [PMID: 21997359 DOI: 10.1038/eye.2011.247] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE We measured the relationship between the occurrence of photopsias (spontaneous phosphenes), and retinitis pigmentosa (RP) subjects' level of vision, light exposure, and psychosocial factors to attempt to confirm RP patients' previous reports of these associations. METHODS A total of 36 RP subjects self-administered PC-based binocular visual acuity, contrast sensitivity, and visual field tests at home twice a week, for 16 sessions in 2-3 months. After each session, subjects reported photopsias during the vision tests and completed questionnaires: Epworth Sleepiness Scale, Stanford Sleepiness Scale, Perceived Stress Scale, and Positive and Negative Affect Schedules. RESULTS Across all subjects, photopsias occurred during 47% of sessions. Five (14%) subjects never noted photopsias, while five others noted photopsias at every session. Two-thirds of subjects experienced photopsias frequently (>20% of sessions). On average, the odds of noticing photopsias increased by 57% for every 1-point increase in mean perceived stress (OR = 1.57; 95% CI: 1.04, 2.4; P = 0.03) or reduced by 38% for every 1-point increase in positive mood (OR=0.62; 95% CI: 0.39, 0.98; P = 0.04), after adjusting for age, gender, and vision. Similarly, the odds of experiencing photopsias during a session increased by 16% for every 3-point increase in perceived stress and decreased by 17% for every 3-point increase in positive mood, after adjusting for age and gender (OR = 1.16; 95% CI: 1.01, 1.33; P = 0.048)(OR = 0.83; 95% CI: 0.73, 0.94; P = 0.004), respectively. Frequency of photopsias was not statistically significantly related to other factors measured. CONCLUSIONS Increased photopsias appear to be related to times when subjects report increased perceived stress and/or decreased positive mood, rather than RP patients' age, level of vision, reported light exposure, or sleepiness.
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Affiliation(s)
- A K Bittner
- Johns Hopkins University; Wilmer Eye Institute, Baltimore, MD 21205, USA.
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25
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Bittner AK, Diener-West M, Dagnelie G. Characteristics and possible visual consequences of photopsias as vision measures are reduced in retinitis pigmentosa. Invest Ophthalmol Vis Sci 2011; 52:6370-6. [PMID: 21693605 DOI: 10.1167/iovs.11-7195] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study explored whether the location of photopsias (spontaneous phosphenes) in retinitis pigmentosa (RP) is related to the severity of vision loss, as has been suggested. METHODS Thirty-two RP subjects self-completed an online survey about photopsias, approximately 1 to 2 months after ETDRS visual acuity (VA), Pelli-Robson contrast sensitivity (CS), and Goldmann visual field (VF) measures were obtained. RESULTS The odds of noting photopsias only or mostly in areas of vision increased as vision was reduced across subjects, by 56% for every 0.1 logMAR VA (95% CI, 1.04-2.33; P = 0.03), 22% for every 0.1 logCS (95% CI, 1.02-1.46; P = 0.03), and 40% for every 1 unit logVF diameter (95% CI, 0.99-1.98; P = 0.06). The odds of noting photopias only in the periphery were reduced by 20% for every 0.1 logCS reduction (95% CI, 0.64-1.02; P = 0.066), and 18% for every 1 unit logVF diameter reduction (95% CI, 0.67-1.001; P = 0.051). For every 0.1 logMAR VA reduction, the odds of indicating that photopsias were located across a larger area over time were 30% greater (95% CI, 1.002-1.70; P = 0.048). The odds of being more aware of photopsias over time were increased as vision was reduced by 48% for every 0.1 logMAR VA (95% CI, 1.04-2.11; P = 0.03) and 18% for every 0.1 logCS (95% CI, 1.01-1.38; P = 0.04). The odds of reporting that photopsias interfere with vision were significantly greater when the photopsias occurred daily, more frequently, or across larger areas over time. CONCLUSIONS These cross-sectional data indicate that in later RP stages, photopsias located more centrally, over larger regions, in areas with vision, and/or observed more frequently may obstruct vision at times and are a potential hindrance for patients' functioning or when obtaining vision measures.
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Affiliation(s)
- Ava K Bittner
- Wilmer Eye Institute, The Johns Hopkins University, Baltimore, Maryland, USA.
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Abstract
In the mammalian retina, excitatory and inhibitory circuitries enable retinal ganglion cells (RGCs) to signal the occurrence of visual features to higher brain areas. This functionality disappears in certain diseases of retinal degeneration because of the progressive loss of photoreceptors. Recent work in a mouse model of retinal degeneration (rd1) found that, although some intraretinal circuitry is preserved and RGCs maintain characteristic physiological properties, they exhibit increased and aberrant rhythmic activity. Here, extracellular recordings were made to assess the degree of aberrant activity in adult rd1 retinas and to investigate the mechanism underlying such behavior. A multi-transistor array with thousands of densely packed sensors allowed for simultaneous recordings of spiking activity in populations of RGCs and of local field potentials (LFPs). The majority of identified RGCs displayed rhythmic (7-10 Hz) but asynchronous activity. The spiking activity correlated with the LFPs, which reflect an average synchronized excitatory input to the RGCs. LFPs initiated from random positions and propagated across the retina. They disappeared when ionotrophic glutamate receptors or electrical synapses were blocked. They persisted in the presence of other pharmacological blockers, including TTX and inhibitory receptor antagonists. Our results suggest that excitation-transmitted laterally through a network of electrically coupled interneurons-leads to large-scale retinal network oscillations, reflected in the rhythmic spiking of most rd1 RGCs. This result may explain forms of photopsias reported by blind patients, while the mechanism involved should be considered in future treatment strategies targeting the disease of retinitis pigmentosa.
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Bittner AK, Edwards L, George M. Coping strategies to manage stress related to vision loss and fluctuations in retinitis pigmentosa. ACTA ACUST UNITED AC 2010; 81:461-8. [PMID: 20591747 DOI: 10.1016/j.optm.2010.03.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 01/28/2010] [Accepted: 03/21/2010] [Indexed: 11/15/2022]
Abstract
BACKGROUND Vision loss in retinitis pigmentosa (RP) is a slowly progressive and inexorable threat to patients' independence. It is not surprising that RP patients, many of whom are young when diagnosed, are at high risk for stress related to their vision loss. To address these issues, eye care providers need to be aware of what coping strategies RP patients use to successfully manage their vision loss. METHODS We held focus groups with 8 legally blind RP patients to help us better understand how they cope with the stress that is generated from their progressive vision loss and fluctuations in vision. Focus group sessions were audio-taped and resulting notes were coded using conventional qualitative analytic techniques. RESULTS Two themes were identified: (1) "kicking and screaming" captured the ways in which RP patients fight to maintain their independence in the face of worsening vision; and (2) "there are so many worse things" describes how RP patients keep their vision loss in perspective. These RP patients demonstrated high levels of resiliency. In particular, they often used humor as a coping mechanism. CONCLUSION Understanding the ways in which RP patients manage their gradual, impending vision loss may lead to improved quality of care for this patient population.
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