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Simunovic MP, Mammo Z. Mechanisms of cone sensitivity loss in retinitis pigmentosa. Ophthalmic Physiol Opt 2024; 44:605-612. [PMID: 38351866 DOI: 10.1111/opo.13280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 04/08/2024]
Abstract
PURPOSE To explore the mechanisms of cone sensitivity loss in retinitis pigmentosa by combining two-colour perimetry with threshold versus intensity (tvi) testing. METHODS Seven subjects with autosomal recessive retinitis pigmentosa and 10 normal subjects were recruited and underwent perimetric testing of one eye using 480- and 640-nm Goldman size V targets presented under scotopic conditions (no background illumination) and against a white background ranging in luminance from -1.5 to 2 log cd m-2 in 0.5 log cd m-2 steps. Data were fitted with tvi functions of the form logT = logT0 + log ((A + A0)/A0)n, where T is the threshold, T0 is the absolute threshold, A is the background intensity, A0 is the 'dark-light' constant and n is a gain constant. RESULTS Reliable tvi functions could not be obtained within the region of the visual field corresponding to loss of the ellipsoid zone on optical coherence tomography. At fixation, changes in both T0 and A0 were observed, consistent with a d1 mechanism loss, which resulted in an upwards and rightwards shift of the tvi function. Losses at [±3°, ±3°] demonstrated changes in T0, consistent with a d3 mechanism loss, resulting in an upwards translation of the tvi curve. CONCLUSIONS Although the absolute cone threshold was elevated at each location, shifts in the tvi function (so-called d1 mechanism loss) at fixation minimise threshold elevation in the presence of white adapting backgrounds, such as those typically employed in standard two-colour perimetry. At more peripheral testing locations, changes in threshold occurred independent of background luminance (so-called d3 mechanism loss). These findings suggest that backgrounds which selectively adapt rods while maintaining cones at, or near, absolute threshold may be preferable to conventional two-colour perimetry for assessing loss of cone sensitivity, especially at the point of fixation.
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Affiliation(s)
- Matthew P Simunovic
- Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
- Retinal Unit, Sydney Eye Hospital, Sydney, New South Wales, Australia
| | - Zaid Mammo
- Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
- Retinal Unit, Sydney Eye Hospital, Sydney, New South Wales, Australia
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Deitch I, Itskov S, Panneman D, Abu Shtaya A, Saban T, Goldberg Y, Ehrenberg M, Cremers FPM, Roosing S, Ben-Yosef T. Autosomal Recessive Rod-Cone Dystrophy with Mild Extra-Ocular Manifestations Due to a Splice-Affecting Variant in BBS9. Curr Issues Mol Biol 2024; 46:2566-2575. [PMID: 38534779 DOI: 10.3390/cimb46030163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/28/2024] Open
Abstract
Bardet-Biedl syndrome (BBS), one of the most common forms of syndromic inherited retinal diseases (IRDs), is characterized by the combination of retinal degeneration with additional extra-ocular manifestations, including obesity, intellectual disability, kidney disease, polydactyly and other skeletal abnormalities. We observed an Israeli patient with autosomal recessive apparently non-syndromic rod-cone dystrophy (RCD). Extra-ocular findings were limited to epilepsy and dental problems. Genetic analysis with a single molecule molecular inversion probes-based panel that targets the exons and splice sites of 113 genes associated with retinitis pigmentosa and Leber congenital amaurosis revealed a homozygous rare missense variant in the BBS9 gene (c.263C>T;p.(Ser88Leu)). This variant, which affects a highly conserved amino acid, is also located in the last base of Exon 3, and predicted to be splice-altering. An in vitro minigene splice assay demonstrated that this variant leads to the partial aberrant splicing of Exon 3. Therefore, we suggest that this variant is likely hypomorphic. This is in agreement with the relatively mild phenotype observed in the patient. Hence, the findings in our study expand the phenotypic spectrum associated with BBS9 variants and indicate that variants in this gene should be considered not only in BBS patients but also in individuals with non-syndromic IRD or IRD with very mild extra-ocular manifestations.
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Affiliation(s)
- Iris Deitch
- Rabin Medical Center, Department of Ophthalmology, Petach Tikva 4941492, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sofia Itskov
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Daan Panneman
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Aasem Abu Shtaya
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva 4941492, Israel
- Unit of Gastroenterology, Carmel Medical Center, Haifa 3436212, Israel
| | - Tal Saban
- Rabin Medical Center, Department of Ophthalmology, Petach Tikva 4941492, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yael Goldberg
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva 4941492, Israel
| | - Miriam Ehrenberg
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Schneider Children's Medical Center of Israel, Department of Ophthalmology, Petach Tikva 4920235, Israel
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Tamar Ben-Yosef
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
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D’Esposito F, Randazzo V, Vega MI, Esposito G, Maltese PE, Torregrossa S, Scibetta P, Listì F, Gagliano C, Scalia L, Pioppo A, Marino A, Piergentili M, Malvone E, Fioretti T, Vitrano A, Piccione M, Avitabile T, Salvatore F, Bertelli M, Costagliola C, Cordeiro MF, Maggio A, D’Alcamo E. RP1 Dominant p.Ser740* Pathogenic Variant in 20 Knowingly Unrelated Families Affected by Rod-Cone Dystrophy: Potential Founder Effect in Western Sicily. Medicina (Kaunas) 2024; 60:254. [PMID: 38399542 PMCID: PMC10890639 DOI: 10.3390/medicina60020254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024]
Abstract
Background and Objectives. Retinitis pigmentosa (RP) is the most common inherited rod-cone dystrophy (RCD), resulting in nyctalopia, progressive visual field, and visual acuity decay in the late stages. The autosomal dominant form (ADRP) accounts for about 20% of RPs. Among the over 30 genes found to date related to ADRP, RP1 pathogenic variants have been identified in 5-10% of cases. In a cohort of RCD patients from the Palermo province on the island of Sicily, we identified a prevalent nonsense variant in RP1, which was associated with ADRP. The objective of our study was to analyse the clinical and molecular data of this patient cohort and to evaluate the potential presence of a founder effect. Materials and Methods. From 2005 to January 2023, 84 probands originating from Western Sicily (Italy) with a diagnosis of RCD or RP and their relatives underwent deep phenotyping, which was performed in various Italian clinical institutions. Molecular characterisation of patients and familial segregation of pathogenic variants were carried out in different laboratories using Sanger and/or next-generation sequencing (NGS). Results. Among 84 probands with RCD/RP, we found 28 heterozygotes for the RP1 variant c.2219C>G, p.Ser740* ((NM_006269.2)*, which was therefore significantly prevalent in this patient cohort. After a careful interview process, we ascertained that some of these patients shared the same pedigree. Therefore, we were ultimately able to define 20 independent family groups with no traceable consanguinity. Lastly, analysis of clinical data showed, in our patients, that the p.Ser740* nonsense variant was often associated with a late-onset and relatively mild phenotype. Conclusions. The high prevalence of the p.Ser740* variant in ADRP patients from Western Sicily suggests the presence of a founder effect, which has useful implications for the molecular diagnosis of RCD in patients coming from this Italian region. This variant can be primarily searched for in RP-affected subjects displaying compatible modes of transmission and phenotypes, with an advantage in terms of the required costs and time for analysis. Moreover, given its high prevalence, the RP1 p.Ser740* variant could represent a potential candidate for the development of therapeutic strategies based on gene editing or translational read-through therapy for suppression of nonsense variants.
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Affiliation(s)
- Fabiana D’Esposito
- Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London SW7 2AZ, UK;
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, 80100 Naples, Italy; (E.M.); (C.C.)
- Genofta s.r.l., Sant’Agnello, 80065 Naples, Italy
| | - Viviana Randazzo
- Eye Clinic, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (V.R.); (S.T.); (P.S.)
| | - Maria Igea Vega
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
| | - Gabriella Esposito
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80100 Naples, Italy; (G.E.); (F.S.)
- CEINGE-Advanced Biotechnologies Franco Salvatore, 80100 Naples, Italy;
| | | | | | - Paola Scibetta
- Eye Clinic, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (V.R.); (S.T.); (P.S.)
| | - Florinda Listì
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
| | - Caterina Gagliano
- Department of Medicine and Surgery, School of Medicine, Kore University of Enna, 94100 Enna, Italy;
| | - Lucia Scalia
- Eye Clinic, Catania University, Policlinico “Rodolico”-San Marco, 95100 Catania, Italy; (L.S.); (T.A.)
| | | | - Antonio Marino
- Department of Ophthalmology, Garibaldi Hospital, 95100 Catania, Italy;
| | - Marco Piergentili
- Department of Ophthalmology, Careggi Teaching Hospital, 50100 Florence, Italy;
| | - Emanuele Malvone
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, 80100 Naples, Italy; (E.M.); (C.C.)
| | - Tiziana Fioretti
- CEINGE-Advanced Biotechnologies Franco Salvatore, 80100 Naples, Italy;
| | - Angela Vitrano
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
| | - Maria Piccione
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
| | - Teresio Avitabile
- Eye Clinic, Catania University, Policlinico “Rodolico”-San Marco, 95100 Catania, Italy; (L.S.); (T.A.)
| | - Francesco Salvatore
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80100 Naples, Italy; (G.E.); (F.S.)
- CEINGE-Advanced Biotechnologies Franco Salvatore, 80100 Naples, Italy;
| | | | - Ciro Costagliola
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, 80100 Naples, Italy; (E.M.); (C.C.)
| | | | - Aurelio Maggio
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
| | - Elena D’Alcamo
- Department of Genetics, Oncohaematology and Rare Diseases, AOOR Villa Sofia-Cervello, 90100 Palermo, Italy; (M.I.V.); (F.L.); (A.V.); (M.P.); (A.M.); (E.D.)
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Jolly JK, Nanda A, Buckley TMW, Pfau M, Bridge H, MacLaren RE. Assessment of Scotopic Function in Rod-Cone Inherited Retinal Degeneration With the Scotopic Macular Integrity Assessment. Transl Vis Sci Technol 2023; 12:10. [PMID: 36749581 PMCID: PMC9919682 DOI: 10.1167/tvst.12.2.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Purpose The scotopic macular integrity assessment (S-MAIA) can perform scotopic assessment to detect localized changes to scotopic rod and cone function. This study is an exploratory investigation of the feasibility of using the S-MAIA in a rod-cone dystrophy population to identify the pattern of loss in scotopic photoreceptor function. Methods Twenty patients diagnosed with a rod-cone dystrophy underwent visual acuity testing, full-field stimulus threshold assessment, and multiple S-MAIA tests after dark adaptation periods of 20 minutes and 45 minutes performed separately. Only right eyes were tested. Three tests were performed following a learning test. A Bland-Altman analysis was used to assess repeatability and agreement between tests after the two time periods. Spatial interpolation maps were created from the group plots to display the pattern of rod and cone loss. Results Learning effects took place between testing sessions 1 and 2 but not 2 and 3. Limits of agreement were larger in the patient eyes than control eyes, but within previously reported values. Using longer adaptation time of 45 minutes did not offer a significant advantage over 20 minutes. Patterns for the cyan and red sensitivities were different, indicating different patterns of loss for rods and cones. Conclusions A dark adaptation time of 20 minutes before testing is sufficient for thresholding. The S-MAIA is suitable for use in patients with a logarithm of the minimum angle of resolution vision of at least 0.7 and provides a viable outcome measure for patients with rod-cone dystrophies and preserved central vision. The spatial information about scotopic function from the S-MAIA provides information about disease processes and progression. Translational Relevance There is a need for scotopic measures for use in clinical trials. Scotopic microperimetry works well in patients with early disease, allowing the extension of recruitment criteria for novel therapies of rod-cone dystrophies.
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Affiliation(s)
- Jasleen K. Jolly
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK,Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK,Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK
| | - Anika Nanda
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Thomas M. W. Buckley
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maximilian Pfau
- Department of Ophthalmology, University of Bonn, Bonn, Germany,Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Holly Bridge
- Oxford Centre for Functional MRI of the Brain (FMRIB), Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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Mahalingam M, Gopalakrishnan S, Parasuraman D, Jayaraj PJ, Raman R. Prescribing patterns of low vision devices in patients with cone-related dystrophies. Indian J Ophthalmol 2023; 71:195-201. [PMID: 36588235 PMCID: PMC10155571 DOI: 10.4103/ijo.ijo_1198_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Purpose The aim of this study was to elucidate the type of low vision devices (LVDs) prescribed for patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy and to analyze the visual improvement with the devices. Methods A retrospective review of 300 electronic medical records of patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy referred to the low vision care (LVC) clinic for the first time between 2014 and 2016 at a tertiary eye care center was done. Collected data included the demographic profile of patients, details of LVDs, and best-corrected vision. Results Out of 300 patients, 62.6% (n = 188) were male and 37.3% (n = 112) were female. Of the cases, 50% (n = 150) had cone-rod dystrophy, 45% (n = 135) had cone dystrophy, and 5% (n = 15) had rod-cone dystrophy. The most commonly prescribed LVD was SEE-TV binocular telescope (n = 6, 2.0%) for distance and dome magnifier (n = 60, 20%) for near. ET-40 dark grey tint (20.6%) was preferred for managing photophobia. There was a statistically significant difference in both distance and near visual acuities with LVDs (P < 0.05) in all categories, except rod-cone dystrophy. Conclusion Early diagnosis with appropriate prescription of LVDs including tints helps in achieving good quality of vision in patients with cone-related dystrophies.
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Affiliation(s)
- Maanasi Mahalingam
- Elite School of Optometry, Units of Medical Reserach Foundation, Chennai, India
| | | | | | - P Jeni Jayaraj
- Department of Low Vision Care, Sankara Nethralaya, Chennai, India
| | - Rajiv Raman
- Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, Tamil Nadu, India
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Meunier I, Bocquet B, Charif M, Dhaenens CM, Manes G, Amati-Bonneau P, Roubertie A, Zanlonghi X, Lenaers G. A ROD-CONE DYSTROPHY IS SYSTEMATICALLY ASSOCIATED TO THE RTN4IP1 RECESSIVE OPTIC ATROPHY. Retina 2021; 41:1771-1779. [PMID: 33315831 PMCID: PMC8297537 DOI: 10.1097/iae.0000000000003054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE RTN4IP1 biallelic mutations cause a recessive optic atrophy, sometimes associated to more severe neurological syndromes, but so far, no retinal phenotype has been reported in RTN4IP1 patients, justifying their reappraisal. METHODS Seven patients from four families carrying biallelic RTN4IP1 variants were retrospectively reviewed, with emphasis on their age of onset, visual acuity, multimodal imaging including color and autofluorescence frames, spectral-domain optical coherence tomography with RNFL and macular analyses. RESULTS Seven patients from four RTN4IP1 families developed in their first decade of life a bilateral recessive optic atrophy with severe central visual loss, and primary nystagmus developed in 5 of 7 patients. Six patients were legally blind. In a second stage, the seven individuals developed a rod-cone dystrophy, sparing the macular zone and the far periphery. This retinal damage was identified by 55° field fundus autofluorescence frames and also by spectral-domain optical coherence tomography scans of the temporal part of the macular zone in five of the seven patients. Full-field electroretinography measurements disclosed reduced b-wave amplitude of the rod responses in all patients but two. Family 4 with the p.R103H and c.601A > T (p.K201*) truncating mutation had further combined neurological signs with cerebellar ataxia, seizures, and intellectual disability. CONCLUSION RTN4IP1 recessive optic atrophy is systematically associated to a rod-cone dystrophy, which suggests that both the retinal ganglion cells and the rods are affected as a result of a deficit in the mitochondrial respiratory chain. Thus, systematic widefield autofluorescence frames and temporal macular scans are recommended for the evaluation of patients with optic neuropathies.
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Affiliation(s)
- Isabelle Meunier
- Institute for Neurosciences of Montpellier U1051, University of Montpellier, Montpellier, France
- National Center in Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | - Béatrice Bocquet
- Institute for Neurosciences of Montpellier U1051, University of Montpellier, Montpellier, France
- National Center in Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | - Majida Charif
- Genetics, and Immuno-cell Therapy Team, Mohammed First University, Oujda, Morocco
| | - Claire-Marie Dhaenens
- Biochemistry and Molecular Biology Department—UF Génopathies, Univ Lille, Lille, France
| | - Gael Manes
- Institute for Neurosciences of Montpellier U1051, University of Montpellier, Montpellier, France
| | | | - Agathe Roubertie
- Institute for Neurosciences of Montpellier U1051, University of Montpellier, Montpellier, France
- National Center in Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | | | - Guy Lenaers
- MitoLab Team, UMR CNRS 6015—INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France
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Charng J, Lamey TM, Thompson JA, McLaren TL, Attia MS, McAllister IL, Constable IJ, Mackey DA, De Roach JN, Chen FK. Edge of Scotoma Sensitivity as a Microperimetry Clinical Trial End Point in USH2A Retinopathy. Transl Vis Sci Technol 2020; 9:9. [PMID: 32974081 PMCID: PMC7488629 DOI: 10.1167/tvst.9.10.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/14/2020] [Indexed: 01/05/2023] Open
Abstract
Purpose Microperimetry is commonly used to assess retinal function. We perform cross-sectional and longitudinal analysis on microperimetry parameters in USH2A retinopathy and explore end points suitable for future clinical trials. Methods Microperimetry was performed using two grids, Grid 1 (18° diameter) and Grid 2 (6° diameter). In Grid 1, four parameters (number of nonscotomatous loci, mean sensitivity [MS], responding point sensitivity [RPS], and edge of scotoma sensitivity [ESS]) were analyzed. In Grid 2, number of nonscotomatous loci and MS were examined. Interocular symmetry was also examined. Longitudinal analysis was conducted in a subset of eyes. Results Microperimetry could be performed in 16 of 21 patients. In Grid 1 (n = 15; average age, 35.6 years), average number of nonscotomatous loci, MS, RPS, and ESS were 46.6 loci, 10.0 dB, 14.7 and 9.6 dB, respectively. In Grid 2 (n = 13; average age, 37.4 years), 12 eyes had measurable sensitivity across the entire grid. Average MS was 23.8 dB. Interocular analysis revealed large 95% confidence intervals for all parameters. Longitudinally, Grid 1 (n = 12, average follow-up 2.6 years) ESS showed the fastest rate of decline (–1.84 dB/y) compared with MS (–0.34 dB/y) and RPS (–0.90 dB/y). Conclusions Our data suggest that ESS may be more useful than MS and RPS in test grids that cover a large extent of the macula. We caution the use of contralateral eye as an internal control. Translational Relevance ESS may decrease the duration or sample size of treatment trials in USH2A retinopathy.
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Affiliation(s)
- Jason Charng
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia
| | - Tina M Lamey
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Terri L McLaren
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Mary S Attia
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia
| | - Ian L McAllister
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia
| | - Ian J Constable
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia
| | - David A Mackey
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia
| | - John N De Roach
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.,Department of Ophthalmology, Perth Children's Hospital, Perth, Western Australia, Australia
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Zampaglione E, Kinde B, Place EM, Navarro-Gomez D, Maher M, Jamshidi F, Nassiri S, Mazzone JA, Finn C, Schlegel D, Comander J, Pierce EA, Bujakowska KM. Copy-number variation contributes 9% of pathogenicity in the inherited retinal degenerations. Genet Med 2020; 22:1079-87. [PMID: 32037395 DOI: 10.1038/s41436-020-0759-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/27/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Current sequencing strategies can genetically solve 55-60% of inherited retinal degeneration (IRD) cases, despite recent progress in sequencing. This can partially be attributed to elusive pathogenic variants (PVs) in known IRD genes, including copy-number variations (CNVs), which have been shown as major contributors to unsolved IRD cases. METHODS Five hundred IRD patients were analyzed with targeted next-generation sequencing (NGS). The NGS data were used to detect CNVs with ExomeDepth and gCNV and the results were compared with CNV detection with a single-nucleotide polymorphism (SNP) array. Likely causal CNV predictions were validated by quantitative polymerase chain reaction (qPCR). RESULTS Likely disease-causing single-nucleotide variants (SNVs) and small indels were found in 55.6% of subjects. PVs in USH2A (11.6%), RPGR (4%), and EYS (4%) were the most common. Likely causal CNVs were found in an additional 8.8% of patients. Of the three CNV detection methods, gCNV showed the highest accuracy. Approximately 30% of unsolved subjects had a single likely PV in a recessive IRD gene. CONCLUSION CNV detection using NGS-based algorithms is a reliable method that greatly increases the genetic diagnostic rate of IRDs. Experimentally validating CNVs helps estimate the rate at which IRDs might be solved by a CNV plus a more elusive variant.
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