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Gocuk SA, Edwards TL, Jolly JK, McGuinness MB, MacLaren RE, Chen FK, Taylor LJ, McLaren TL, Lamey TM, Thompson JA, Ayton LN. Retinal Characteristics of Female Choroideremia Carriers: Multimodal Imaging, Microperimetry, and Genetics. Ophthalmol Retina 2024:S2468-6530(24)00304-X. [PMID: 38936773 DOI: 10.1016/j.oret.2024.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/14/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024]
Abstract
PURPOSE To describe visual function and retinal features of female carriers of choroideremia (CHM), using multimodal imaging and microperimetry. DESIGN Cross-sectional cohort study. PARTICIPANTS AND CONTROLS Choroideremia carriers seen in Australia (Melbourne or Perth) or the United Kingdom (Oxford or Cambridge) between 2012 and 2023. Healthy age-matched controls seen in Melbourne, Australia, between 2022 and 2023. METHODS Participants had visual acuity, fundus-tracked microperimetry, OCT, and fundus autofluorescence imaging performed. Choroideremia carriers were either genetically or clinically confirmed (i.e., obligate carriers). Choroideremia carriers were grouped according to their retinal phenotype and compared with healthy controls. Statistical analyses were performed on StataBE (v18.0). MAIN OUTCOME MEASURES Best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), average retinal sensitivity, volume of macular hill of vision (HoV), inner retinal thickness, and photoreceptor complex (PRC) thickness. RESULTS Eighty-six eyes of 43 CHM carriers and 60 eyes of 30 healthy controls were examined using multimodal imaging and microperimetry. Median age was 54 and 48.5 years for CHM carriers and controls, respectively (P = 0.18). Most CHM carriers (86%) were genetically confirmed. Choroideremia carriers and controls had strong intereye correlation between eyes for BCVA and average retinal sensitivity (P < 0.001). Low-luminance visual acuity and macular HoV tests were sensitive tests to detect changes in CHM carriers with mild phenotypes (i.e., fine and coarse). Choroideremia carriers with geographic or male-pattern phenotypes had reduced BCVA, LLVA, retinal sensitivity, and retinal thinning, compared with healthy controls. Retinal thickening of the inner retina was observed in the central 1°, despite generalized thinning of the PRC in the central 7°, indicating retinal remodeling in CHM carriers, compared with controls. There were no genotype-phenotype correlations observed. CONCLUSIONS Female carriers of CHM with severe retinal phenotypes (i.e., geographic or male pattern) have significantly decreased visual function and retinal structural changes when compared with age-matched controls and those carriers with milder phenotypes. Low-luminance visual acuity and volumetric measures of the macular HoV were found to be the most sensitive functional tests to detect milder retinal disease (fine and coarse phenotypes) in CHM carriers. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Sena A Gocuk
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Thomas L Edwards
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Jasleen K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, United Kingdom; Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Myra B McGuinness
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Fred K Chen
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia; Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, Western Australia, Australia
| | - Laura J Taylor
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Terri L McLaren
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, 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
| | - Tina M Lamey
- 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
| | - Lauren N Ayton
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.
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Wynne N, Jiang YY, Aleman TS, Morgan JIW. FOVEAL PHENOTYPES IN CHOROIDEREMIA ON ADAPTIVE OPTICS SCANNING LIGHT OPHTHALMOSCOPY. Retina 2024; 44:659-668. [PMID: 38531059 PMCID: PMC10972540 DOI: 10.1097/iae.0000000000003995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
PURPOSE Choroideremia is an X-linked inherited retinal degeneration involving the choriocapillaris, retinal pigment epithelium, and photoreceptors. Adaptive optics scanning light ophthalmoscopy allows visualization of retinal structure at the level of individual cells and is well poised to provide insight into the pathophysiologic mechanisms underpinning the retinal degeneration in choroideremia. METHODS Foveal adaptive optics scanning light ophthalmoscopy images of 102 eyes of 54 individuals with choroideremia were analyzed. Measures were compared with those from standard clinical imaging. Visual acuity was also measured and compared with quantitative foveal metrics. RESULTS The 3 distinct phenotypes observed were: relatively normal (5 eyes, 4 individuals), spiderweb (9 eyes, 7 individuals), and salt and pepper (87 eyes, 47 individuals). Peak cone density (86 eyes of 51 individuals) was significantly lower in choroideremia than in healthy retinas (P < 0.0001, range: 29,382-157,717 cones/mm2). Peak cone density was significantly related to extent of retained ellipsoid zone on en face optical coherence tomography (r2 = 0.47, P = 0.0009) and inversely related to visual acuity (r2 = 0.20, P = 0.001). CONCLUSION Distinct phenotypes can be observed on adaptive optics scanning light ophthalmoscopy imaging in choroideremia that cannot always be discerned on standard clinical imaging. Quantitative measures on adaptive optics imaging are related to the structural and functional severity of disease.
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Affiliation(s)
- Niamh Wynne
- Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Yu You Jiang
- Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, United States
| | - Tomas S Aleman
- Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, United States
| | - Jessica IW Morgan
- Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, United States
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Waldock WJ, Taylor LJ, Sperring S, Staurenghi F, Martinez-Fernandez de la Camara C, Whitfield J, Clouston P, Yusuf IH, MacLaren RE. A hypomorphic variant of choroideremia is associated with a novel intronic mutation that leads to exon skipping. Ophthalmic Genet 2024; 45:210-217. [PMID: 38273808 DOI: 10.1080/13816810.2023.2270554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/09/2023] [Indexed: 01/27/2024]
Abstract
INTRODUCTION Molecular confirmation of pathogenic sequence variants in the CHM gene is required prior to enrolment in retinal gene therapy clinical trials for choroideremia. Individuals with mild choroideremia have been reported. The molecular basis of genotype-phenotype associations is of clinical relevance since it may impact on selection for retinal gene therapy. METHODS AND MATERIALS Genetic testing and RNA analysis were undertaken in a patient with mild choroideremia to confirm the pathogenicity of a novel intronic variant in CHM and to explore the mechanism underlying the mild clinical phenotype. RESULTS A 42-year-old male presented with visual field loss. Fundoscopy and autofluorescence imaging demonstrated mild choroideremia for his age. Genetic analysis revealed a variant at a splice acceptor site in the CHM gene (c.1350-3C > G). RNA analysis demonstrated two out-of-frame transcripts, suggesting pathogenicity, without any detectable wildtype transcripts. One of the two out-of-frame transcripts is present in very low levels in healthy controls. DISCUSSION Mild choroideremia may result from +3 or -3 splice site variants in CHM. It is presumed that the resulting mRNA transcripts may be partly functional, thereby preventing the development of the null phenotype. Choroideremia patients with such variants may present challenges for gene therapy since there may be residual transcript activity which could result in long-lasting visual function which is atypical for this disease.
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Affiliation(s)
| | - Laura J Taylor
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sian Sperring
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Federica Staurenghi
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Cristina Martinez-Fernandez de la Camara
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Penny Clouston
- Oxford Regional Genetics Laboratories, Churchill Hospital, Oxford, UK
| | - Imran H Yusuf
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Abdalla Elsayed MEA, Taylor LJ, Josan AS, Fischer MD, MacLaren RE. Choroideremia: The Endpoint Endgame. Int J Mol Sci 2023; 24:14354. [PMID: 37762657 PMCID: PMC10532430 DOI: 10.3390/ijms241814354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/25/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Choroideremia is an X-linked retinal degeneration resulting from the progressive, centripetal loss of photoreceptors and choriocapillaris, secondary to the degeneration of the retinal pigment epithelium. Affected individuals present in late childhood or early teenage years with nyctalopia and progressive peripheral visual loss. Typically, by the fourth decade, the macula and fovea also degenerate, resulting in advanced sight loss. Currently, there are no approved treatments for this condition. Gene therapy offers the most promising therapeutic modality for halting or regressing functional loss. The aims of the current review are to highlight the lessons learnt from clinical trials in choroideremia, review endpoints, and propose a future strategy for clinical trials.
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Affiliation(s)
- Maram E. A. Abdalla Elsayed
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Laura J. Taylor
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Amandeep S. Josan
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - M. Dominik Fischer
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
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Gocuk SA, Jolly JK, Edwards TL, Ayton LN. Female carriers of X-linked inherited retinal diseases - Genetics, diagnosis, and potential therapies. Prog Retin Eye Res 2023; 96:101190. [PMID: 37406879 DOI: 10.1016/j.preteyeres.2023.101190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
Inherited retinal diseases (IRDs) are a group of heterogeneous conditions that cause progressive vision loss, typically due to monogenic mutations. Female carriers of X-linked IRDs have a single copy of the disease-causing gene, and therefore, may exhibit variable clinical signs that vary from near normal retina to severe disease and vision loss. The relationships between individual genetic mutations and disease severity in X-linked carriers requires further study. This review summarises the current literature surrounding the spectrum of disease seen in female carriers of choroideremia and X-linked retinitis pigmentosa. Various classification systems are contrasted to accurately grade retinal disease. Furthermore, genetic mechanisms at the early embryonic stage are explored to potentially explain the variability of disease seen in female carriers. Future research in this area will provide insight into the association between genotype and retinal phenotypes of female carriers, which will guide in the management of these patients. This review acknowledges the importance of identifying which patients may be at high risk of developing severe symptoms, and therefore should be considered for emerging treatments, such as retinal gene therapy.
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Affiliation(s)
- Sena A Gocuk
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jasleen K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK
| | - Thomas L Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lauren N Ayton
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia; Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia.
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