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Kumaran N, Georgiou M, Bainbridge JWB, Bertelsen M, Larsen M, Blanco-Kelly F, Ayuso C, Tran HV, Munier FL, Kalitzeos A, Michaelides M. Retinal Structure in RPE65-Associated Retinal Dystrophy. Invest Ophthalmol Vis Sci 2020; 61:47. [PMID: 32347917 PMCID: PMC7401957 DOI: 10.1167/iovs.61.4.47] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose RPE65-associated retinal dystrophy (RPE65-RD) is an early onset, progressive, severe retinal dystrophy. We sought to characterize the natural history of retinal degeneration in affected individuals. Methods We performed cross-sectional and longitudinal quantitative and qualitative assessments of retinal architecture in RPE65-RD using spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) imaging. Twenty-six subjects (mean age, 14.8 years, range, 5-24 years) with RPE65-RD underwent SD-OCT and FAF imaging, of whom 14 subjects were followed up over time. Foveal thickness (FT), outer nuclear layer thickness (ONLT), ellipsoid zone width (EZW), and ellipsoid zone area (EZA) were calculated where possible. These were correlated with age, best corrected visual acuity (BCVA), and central 30° retinal sensitivity (V30). Intra-observer agreement, test-retest repeatability, and interocular symmetry were also investigated. Results We identified structural interocular symmetry, the presence of autofluorescence in 46% (12/26) of subjects, and the presence of foveal hypoplasia (associated with significantly worse BCVA) in 50% of subjects. EZW and EZA were measurable in 67% (35/52) and 37% (19/52) of eyes, respectively, with both demonstrating good agreement on repeated measurement. The annual rate of progression using EZW was -300.63 µm/year, and -1.17 mm2/year in EZA. EZW was found to have a statistically significant correlation with BCVA and V30. Conclusions We identified the presence of autofluorescence in half of our subjects, with foveal hypoplasia also noted in half of our cohort. EZW, and to a lesser extent EZA, were robust measures of retinal degeneration and represent valuable metrics to determine the impact of intervention. (ClinicalTrials.gov number NCT02714816.).
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Sun W, Li S, Xiao X, Wang P, Zhang Q. Genotypes and phenotypes of genes associated with achromatopsia: A reference for clinical genetic testing. Mol Vis 2020; 26:588-602. [PMID: 32913385 PMCID: PMC7479066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 08/20/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Achromatopsia is a congenital autosomal recessive cone disorder, and it has been found to be associated with six genes. However, pathogenic variants in these six genes have been identified in patients with various retinal dystrophies with the exception of achromatopsia. Thus, this study aims to investigate the contribution of these genes in hereditary retinal diseases and the potential genotype-phenotype correlations. METHODS Biallelic variants in six achromatopsia-related genes, namely, CNGA3, CNGB3, GNAT2, ATF6, PDE6C, and PDE6H, were analyzed based on data obtained from 7,195 probands with different eye conditions. A systematic genotype-phenotype analysis of these genes was performed based on these data, along with the data reported in the literature. RESULTS Biallelic potential pathogenic variants (PPVs) in five of the six genes were identified in 119 probands with genetic eye diseases. The variants in CNGA3 were the most common and accounted for 81.5% (97/119). Of the 119 probands, 62.2% (74/119) have cone-rod dystrophy, whereas only 25.2% (30/119) have achromatopsia. No biallelic pathogenic variants in these genes were identified in patients with rod-dominant degeneration. A systematic review of genotypes and phenotypes revealed certain characteristics of each of the six genes, providing clues for the pathogenicity evaluation of the variants of the genes. CONCLUSIONS PPVs in the six genes were identified in various inherited retinal degeneration diseases, most of which are cone-dominant diseases but no rod-dominant diseases based on the data from a cohort of 7,195 probands with different eye conditions. The systematic genotype-phenotype analysis of these genes will be useful in drafting guidelines for the clinical genetic diagnostic application for the investigated genes.
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Litts KM, Okada M, Heeren TFC, Kalitzeos A, Rocco V, Mastey RR, Singh N, Kane T, Kasilian M, Fruttiger M, Michaelides M, Carroll J, Egan C. Longitudinal Assessment of Remnant Foveal Cone Structure in a Case Series of Early Macular Telangiectasia Type 2. Transl Vis Sci Technol 2020; 9:27. [PMID: 32818114 PMCID: PMC7396184 DOI: 10.1167/tvst.9.4.27] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/13/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the extent of remnant cone structure within early foveal ellipsoid zone (EZ) lesions in macular telangiectasia type 2 longitudinally using both confocal and split detector adaptive optics scanning light ophthalmoscopy (AOSLO). Methods Spectral domain optical coherence tomography (SDOCT), confocal and split detector AOSLO were acquired from seven patients (10 eyes) with small (early) EZ lesions on SDOCT secondary to macular telangiectasia type 2 at baseline, 6 months, and 12 months. The presence of cone structure on AOSLO in areas of EZ loss as well as cones at 1° eccentricity, and their change over time were quantified. Results By split detector AOSLO, remnant cone structure was identified within and on the borders of all foveal EZ lesions. Within the extent of these lesions, cone spacing ranged from 4.97 to 9.95 µm at baseline, 5.30 to 6.10 µm at 6 months, and 4.99 to 7.12 µm at 12 months. Four eyes with significantly smaller EZ lesions showed evidence of recovery of EZ reflectivity on SDOCT B-scans. Remnant cone structure was identified in some areas where EZ reflectivity recovered at the following time point. Eyes that showed recovery of EZ reflectivity had a continuous external limiting membrane. Conclusions Remnant cone structure can persist within small SDOCT-defined EZ lesions, which can wax and wane in appearance over time. AOSLO can help to inform the interpretation of SDOCT imaging. Translational Relevance The absence of EZ in early macular telangiectasia type 2 and other retinal conditions needs careful interpretation because it does not always indicate an absence of underlying cone structure. The integrity of the external limiting membrane may better predict the presence of remnant cone structure and recovery of EZ reflectivity.
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Affiliation(s)
- Katie M Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mali Okada
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Tjebo F C Heeren
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Angelos Kalitzeos
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Vincent Rocco
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Rebecca R Mastey
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Navjit Singh
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Thomas Kane
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Melissa Kasilian
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Marcus Fruttiger
- University College London Institute of Ophthalmology, London, UK
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Catherine Egan
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University College London Institute of Ophthalmology, London, UK
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Yuan S, Qi R, Fang X, Wang X, Zhou L, Sheng X. Two novel PDE6C gene mutations in Chinese family with achromatopsia. Ophthalmic Genet 2020; 41:591-598. [PMID: 32787476 DOI: 10.1080/13816810.2020.1802762] [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: 10/23/2022]
Abstract
Background: Achromatopsia (ACHM) is an inherited retinal disease affecting the cone cell function. To date, six pathogenic genes of ACHM have been identified. However, the diagnostic and therapeutic methods of this disorder remain limited. Herein, to characterize the clinical features and genetic causes of three affected siblings in a Chinese family with ACHM, we used target next-generation sequencing (NGS) and found new pathogenic factors associated with ACHM in this family. Materials and methods: Three patients with ACHM and three healthy family members were included in this study. All participants received comprehensive ophthalmic tests. NGS approach was performed on the patients to determine the causative mutation for this family. The silico analysis was also applied to predict the pathogenesis of identified mutations. Results: Genetic assessments revealed compound heterozygous mutations of the PDE6C gene (c.1413 + 1 G > C, c.305 G > A), carried by all three patients. Both mutations were novel and predicted to be deleterious by six types of online predictive software. The heterozygous PDE6C missense mutation (c.305 G > A) was found from the mother and the heterozygous PDE6C splice site mutation (c.1413 + 1 G > C) was found in the father and all the children. All patients in the family showed typical signs and symptoms of ACHM. Conclusions: We report novel compound heterozygous PDE6C mutations in causing ACHM and further confirm the clinical diagnosis. Our study extends the genotypic spectrums for PDE6C-ACHM and better illustrates its genotype-phenotype correlations, which would help the ACHM patients with better genetic diagnosis, prognosis, and gene treatment.
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Affiliation(s)
- Shiqin Yuan
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Rui Qi
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China.,Aier Eye Hospital Group, Hubin Aier Eye Hospital , Binzhou, Shangdong, China
| | - Xinhe Fang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xiaoguang Wang
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Liang Zhou
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
| | - Xunlun Sheng
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region (First Affiliated Hospital of Northwest University for Nationalities) , Yinchuan, China
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Morgan JIW, Chen M, Huang AM, Jiang YY, Cooper RF. Cone Identification in Choroideremia: Repeatability, Reliability, and Automation Through Use of a Convolutional Neural Network. Transl Vis Sci Technol 2020; 9:40. [PMID: 32855844 PMCID: PMC7424931 DOI: 10.1167/tvst.9.2.40] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 04/10/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Adaptive optics imaging has enabled the visualization of photoreceptors both in health and disease. However, there remains a need for automated accurate cone photoreceptor identification in images of disease. Here, we apply an open-source convolutional neural network (CNN) to automatically identify cones in images of choroideremia (CHM). We further compare the results to the repeatability and reliability of manual cone identifications in CHM. Methods We used split-detection adaptive optics scanning laser ophthalmoscopy to image the inner segment cone mosaic of 17 patients with CHM. Cones were manually identified twice by one experienced grader and once by two additional experienced graders in 204 regions of interest (ROIs). An open-source CNN either pre-trained on normal images or trained on CHM images automatically identified cones in the ROIs. True and false positive rates and Dice's coefficient were used to determine the agreement in cone locations between data sets. Interclass correlation coefficient was used to assess agreement in bound cone density. Results Intra- and intergrader agreement for cone density is high in CHM. CNN performance increased when it was trained on CHM images in comparison to normal, but had lower agreement than manual grading. Conclusions Manual cone identifications and cone density measurements are repeatable and reliable for images of CHM. CNNs show promise for automated cone selections, although additional improvements are needed to equal the accuracy of manual measurements. Translational Relevance These results are important for designing and interpreting longitudinal studies of cone mosaic metrics in disease progression or treatment intervention in CHM.
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Affiliation(s)
- Jessica I W Morgan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Min Chen
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew M Huang
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Yu You Jiang
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert F Cooper
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.,Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.,Currently at the Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin and the Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, USA
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56
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Georgiou M, Singh N, Kane T, Robson AG, Kalitzeos A, Hirji N, Webster AR, Dubra A, Carroll J, Michaelides M. Photoreceptor Structure in GNAT2-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2020; 61:40. [PMID: 32203983 PMCID: PMC7401776 DOI: 10.1167/iovs.61.3.40] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to report GNAT2-associated achromatopsia (GNAT2-ACHM) natural history, characterize photoreceptor mosaic, and determine a therapeutic window for potential intervention. Methods Patients with GNAT2-ACHM were recruited from a single tertiary referral eye center (Moorfields Eye Hospital, London, UK). We performed longitudinal clinical evaluation and ophthalmic examination, and multimodal retinal imaging, including adaptive optics scanning light ophthalmoscopy, quantitative analysis of the cone mosaic, and outer nuclear layer (ONL) thickness, including cone densities evaluation in selected regions of interest and comparison with reported healthy controls. Results All nine subjects (3 women) presented with nystagmus, decreased visual acuity (VA), light sensitivity, and highly variable color vision loss. One patient had normal color vision and better VA. Mean VA was 1.01 (±0.10) logarithms of the minimal angle of resolution (LogMAR) at baseline, and 1.04 (±0.10) LogMAR after a mean follow-up (range) of 7.6 years (1.7−12.8 years). Optical coherence tomography showed preservation of the foveal ellipsoid zone (EZ; n = 8; 88.9%), and EZ disruption (n = 1; 11.1%). Mean ONL thickness (range, ± SD) was 84.72 µm (28.57−113.33, ± 25.46 µm) and 86.47 µm (28.57−113.33, ± 24.65 µm) for right and left eyes, respectively. Mean cone densities (±SD) at 190 µm, 350 µm, and 500 µm from the foveal center, were 48.4 (±24.6), 37.8 (±14.7), and 30.7 (±9.9), ×103 cones/mm2, respectively. Mean cone densities were lower than these of unaffected individuals, but with an overlap. Conclusions The cone mosaic in GNAT2-ACHM is relatively well preserved, potentially allowing for a wide therapeutic window for cone-directed interventions.
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Garafalo AV, Cideciyan AV, Héon E, Sheplock R, Pearson A, WeiYang Yu C, Sumaroka A, Aguirre GD, Jacobson SG. Progress in treating inherited retinal diseases: Early subretinal gene therapy clinical trials and candidates for future initiatives. Prog Retin Eye Res 2020; 77:100827. [PMID: 31899291 PMCID: PMC8714059 DOI: 10.1016/j.preteyeres.2019.100827] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/21/2019] [Accepted: 12/26/2019] [Indexed: 12/15/2022]
Abstract
Due to improved phenotyping and genetic characterization, the field of 'incurable' and 'blinding' inherited retinal diseases (IRDs) has moved substantially forward. Decades of ascertainment of IRD patient data from Philadelphia and Toronto centers illustrate the progress from Mendelian genetic types to molecular diagnoses. Molecular genetics have been used not only to clarify diagnoses and to direct counseling but also to enable the first clinical trials of gene-based treatment in these diseases. An overview of the recent reports of gene augmentation clinical trials by subretinal injections is used to reflect on the reasons why there has been limited success in this early venture into therapy. These first-in human experiences have taught that there is a need for advancing the techniques of delivery of the gene products - not only for refining further subretinal trials, but also for evaluating intravitreal delivery. Candidate IRDs for intravitreal gene delivery are then suggested to illustrate some of the disorders that may be amenable to improvement of remaining central vision with the least photoreceptor trauma. A more detailed understanding of the human IRDs to be considered for therapy and the calculated potential for efficacy should be among the routine prerequisites for initiating a clinical trial.
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Affiliation(s)
- Alexandra V Garafalo
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alexander Pearson
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Caberry WeiYang Yu
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Alexander Sumaroka
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Georgiou M, Litts KM, Singh N, Kane T, Patterson EJ, Hirji N, Kalitzeos A, Dubra A, Michaelides M, Carroll J. Intraobserver Repeatability and Interobserver Reproducibility of Foveal Cone Density Measurements in CNGA3- and CNGB3-Associated Achromatopsia. Transl Vis Sci Technol 2020; 9:37. [PMID: 32832242 PMCID: PMC7414701 DOI: 10.1167/tvst.9.7.37] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/13/2020] [Indexed: 01/06/2023] Open
Abstract
Purpose To examine repeatability and reproducibility of foveal cone density measurements in patients with CNGA3 - and CNGB3-associated achromatopsia (ACHM) using split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Methods Thirty foveae from molecularly confirmed subjects with ACHM, half of whom harbored disease-causing variants in CNGA3 and half in CNGB3, underwent nonconfocal split-detection AOSLO imaging. Cone photoreceptors within the manually delineated rod-free zone were manually identified twice by two independent observers. The coordinates of the marked cones were used for quantifying foveal cone density. Cone density and difference maps were generated to compare cone topography between trials. Results We observed excellent intraobserver repeatability in foveal cone density estimates, with intraclass correlation coefficients (ICCs) ranging from 0.963 to 0.991 for CNGA3 and CNGB3 subjects. Interobserver reproducibility was also excellent for both CNGA3 (ICC = 0.952; 95% confidence interval [CI], 0.903-1.0) and CNGB3 (ICC = 0.968; 95% CI, 0.935-1.0). However, Bland-Altman analysis revealed bias between observers. Conclusions Foveal cone density can be measured using the described method with good repeatability and reproducibility both for CNGA3- and CNGB3-associated ACHM. Any degree of bias observed among the observers is of uncertain clinical significance but should be evaluated on a study-specific basis. Translational Relevance This approach could be used to explore disease natural history, as well as to facilitate stratification of patients and monitor efficacy of interventions for ongoing and upcoming ACHM gene therapy trials.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Katie M Litts
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Emily J Patterson
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
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Hirji N, Theodorou M, Bainbridge JW, Venturi N, Michaelides M. Nystagmus and optical coherence tomography findings in CNGB3-associated achromatopsia. J AAPOS 2020; 24:82.e1-82.e7. [PMID: 32151571 DOI: 10.1016/j.jaapos.2019.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/13/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022]
Abstract
PURPOSE To describe the nystagmus characteristics of subjects with molecularly confirmed CNGB3-associated achromatopsia and report the spectral domain optical coherence tomography (SD-OCT) findings in these individuals. METHODS Adults and children with CNGB3-achromatopsia underwent visual acuity testing, ocular motility assessments, video nystagmography, and SD-OCT imaging. Qualitative assessment of foveal structure was performed by grading SD-OCT images into one of five categories. RESULTS A total of 18 subjects (11 adults) were included. The majority demonstrated a phoria, with manifest strabismus present in only 3 subjects. The predominant nystagmus waveform within the cohort was pure pendular. Nine individuals demonstrated a mixture of waveforms. Nystagmus frequencies were 4-8 cycles/second, with no notable differences in eye movements between adults and children. SD-OCT imaging revealed a continuous ellipsoid zone (EZ) at the fovea in 2 subjects (grade 1) and EZ disruption (grade 2) in the remaining 16. Retinal structure characteristics were symmetrical in both eyes in each subject. CONCLUSIONS In our study cohort, nystagmus in CNGB3-associated achromatopsia had distinctive features, and the majority of subjects had retinal abnormalities at the fovea on SD-OCT. Early use of SD-OCT in the clinical work-up may eliminate the need for more invasive investigations, such as neuro-imaging.
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Affiliation(s)
- Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom
| | - Maria Theodorou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom.
| | - James W Bainbridge
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom
| | | | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom
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60
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Mastey RR, Georgiou M, Langlo CS, Kalitzeos A, Patterson EJ, Kane T, Singh N, Vincent A, Moore AT, Tsang SH, Lin JH, Young MP, Hartnett ME, Héon E, Kohl S, Michaelides M, Carroll J. Characterization of Retinal Structure in ATF6-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2019; 60:2631-2640. [PMID: 31237654 PMCID: PMC6594318 DOI: 10.1167/iovs.19-27047] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Purpose Mutations in six genes have been associated with achromatopsia (ACHM): CNGA3, CNGB3, PDE6H, PDE6C, GNAT2, and ATF6. ATF6 is the most recent gene to be identified, though thorough phenotyping of this genetic subtype is lacking. Here, we sought to test the hypothesis that ATF6-associated ACHM is a structurally distinct form of congenital ACHM. Methods Seven genetically confirmed subjects from five nonconsanguineous families were recruited. Foveal hypoplasia and the integrity of the ellipsoid zone (EZ) band (a.k.a., IS/OS) were graded from optical coherence tomography (OCT) images. Images of the photoreceptor mosaic were acquired using confocal and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Parafoveal cone and rod density values were calculated and compared to published normative data as well as data from two subjects harboring CNGA3 or CNGB3 mutations who were recruited for comparative purposes. Additionally, nonconfocal dark-field AOSLO images of the retinal pigment epithelium were obtained, with quantitative analysis performed in one subject with ATF6-ACHM. Results Foveal hypoplasia was observed in all subjects with ATF6 mutations. Absence of the EZ band within the foveal region (grade 3) or appearance of a hyporeflective zone (grade 4) was seen in all subjects with ATF6 using OCT. There was no evidence of remnant foveal cone structure using confocal AOSLO, although sporadic cone-like structures were seen in nonconfocal split-detection AOSLO. There was a lack of cone structure in the parafovea, in direct contrast to previous reports. Conclusions Our data demonstrate a near absence of cone structure in subjects harboring ATF6 mutations. This implicates ATF6 as having a major role in cone development and suggests that at least a subset of subjects with ATF6-ACHM have markedly fewer cellular targets for cone-directed gene therapies than do subjects with CNGA3- or CNGB3-ACHM.
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Affiliation(s)
- Rebecca R Mastey
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Christopher S Langlo
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Emily J Patterson
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, The University of Toronto, Toronto, Canada
| | - Anthony T Moore
- Department of Ophthalmology, University of California-San Francisco Medical School, San Francisco, California, United States
| | - Stephen H Tsang
- Jonas Children's Vision Care, Departments of Ophthalmology, Pathology and Cell Biology, Columbia Stem Cell Initiative, New York, New York, United States
| | - Jonathan H Lin
- Department of Ophthalmology, University of California-San Diego, La Jolla, California, United States.,Department of Pathology, University of California-San Diego, La Jolla, California, United States
| | - Marielle P Young
- Moran Eye Center, University of Utah, Salt Lake City, Utah, United States
| | | | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, The University of Toronto, Toronto, Canada
| | - Susanne Kohl
- Centre for Ophthalmology Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.,Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Georgiou M, Robson AG, Singh N, Pontikos N, Kane T, Hirji N, Ripamonti C, Rotsos T, Dubra A, Kalitzeos A, Webster AR, Carroll J, Michaelides M. Deep Phenotyping of PDE6C-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2019; 60:5112-5123. [PMID: 31826238 PMCID: PMC6905659 DOI: 10.1167/iovs.19-27761] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/23/2019] [Indexed: 11/29/2022] Open
Abstract
Purpose To perform deep phenotyping of subjects with PDE6C achromatopsia and examine disease natural history. Methods Eight subjects with disease-causing variants in PDE6C were assessed in detail, including clinical phenotype, best-corrected visual acuity, fundus autofluorescence, and optical coherence tomography. Six subjects also had confocal and nonconfocal adaptive optics scanning light ophthalmoscopy, axial length, international standard pattern and full-field electroretinography (ERG), short-wavelength flash (S-cone) ERGs, and color vision testing. Results All subjects presented with early-onset nystagmus, decreased best-corrected visual acuity, light sensitivity, and severe color vision loss, and five of them had high myopia. We identified three novel disease-causing variants and provide phenotype data associated with nine variants for the first time. No subjects had foveal hypoplasia or residual ellipsoid zone (EZ) at the foveal center; one had an absent EZ, three had a hyporeflective zone, and four had outer retinal atrophy. The mean width of the central EZ lesion on optical coherence tomography at baseline was 1923 μm. The mean annual increase in EZ lesion size was 48.3 μm. Fundus autofluorescence revealed a central hypoautofluorescence with a surrounding ring of increased signal (n = 5). The mean hypoautofluorescent area at baseline was 3.33 mm2 and increased in size by a mean of 0.13 mm2/year. Nonconfocal adaptive optics scanning light ophthalmoscopy revealed residual foveal cones in only one of two cases. Full-field ERGs were consistent with severe generalized cone system dysfunction but with relative preservation of S-cone sensitivity. Conclusions PDE6C retinopathy is a severe cone dysfunction syndrome often presenting as typical achromatopsia but without foveal hypoplasia. Myopia and slowly progressive maculopathy are common features. There are few (if any) residual foveal cones for intervention in older adults.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Anthony G. Robson
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | | | - Tryfon Rotsos
- First Division of Ophthalmology, National and Kapodistrian University of Athens, General Hospital of Athens, Athens, Greece
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Andrew R. Webster
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
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Baraas RC, Pedersen HR, Hagen LA. Single-cone imaging in inherited and acquired colour vision deficiencies. Curr Opin Behav Sci 2019. [DOI: 10.1016/j.cobeha.2019.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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63
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Gill JS, Moosajee M, Dubis AM. Cellular imaging of inherited retinal diseases using adaptive optics. Eye (Lond) 2019; 33:1683-1698. [PMID: 31164730 PMCID: PMC7002587 DOI: 10.1038/s41433-019-0474-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/25/2019] [Accepted: 04/25/2019] [Indexed: 12/14/2022] Open
Abstract
Adaptive optics (AO) is an insightful tool that has been increasingly applied to existing imaging systems for viewing the retina at a cellular level. By correcting for individual optical aberrations, AO offers an improvement in transverse resolution from 10-15 μm to ~2 μm, enabling assessment of individual retinal cell types. One of the settings in which its utility has been recognised is that of the inherited retinal diseases (IRDs), the genetic and clinical heterogeneity of which warrants better cellular characterisation. In this review, we provide a summary of the basic principles of AO, its integration into multiple retinal imaging modalities and its clinical applications, focusing primarily on IRDs. Furthermore, we present a comprehensive summary of AO-based cellular findings in IRDs according to their associated disease-causing genes.
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Affiliation(s)
- Jasdeep S Gill
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, 162 City Road, London, EC1V 9PD, UK
- Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK
| | - Adam M Dubis
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, 162 City Road, London, EC1V 9PD, UK.
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64
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Huckenpahler AL, Carroll J, Salmon AE, Sajdak BS, Mastey RR, Allen KP, Kaplan HJ, McCall MA. Noninvasive Imaging and Correlative Histology of Cone Photoreceptor Structure in the Pig Retina. Transl Vis Sci Technol 2019; 8:38. [PMID: 31867139 PMCID: PMC6922271 DOI: 10.1167/tvst.8.6.38] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 10/04/2019] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To evaluate different methods of studying cone photoreceptor structure in wild-type (WT) and transgenic pigs carrying the human rhodopsin P23H mutant gene (TgP23H). METHODS For in vivo imaging, pigs were anesthetized with tiletamine-zolazepam and isoflurane and given lidocaine-bupivacaine retrobulbar injections. Stay sutures and a custom head mount were used to hold and steer the head for adaptive optics scanning light ophthalmoscopy (AOSLO). Six WT and TgP23H littermates were imaged at postnatal day 30 (P30), P90, and P180 with AOSLO and optical coherence tomography (OCT), and two additional sets of littermates were imaged at P3 and P15 with OCT only. AOSLO imaging and correlative differential interference contrast microscopy were performed on a P240 WT pig and on WT and TgP23H littermates at P30 and P180. RESULTS AOSLO cone density generally underestimates histology density (mean difference ± SD = 24.8% ± 21.4%). The intensity of the outer retinal hyperreflective OCT band attributed to photoreceptors is attenuated in TgP23H pigs at all ages. In contrast, AOSLO images show cones that retain inner and outer segments through P180. At retinal locations outside the visual streak, TgP23H pigs show a heterogeneous degenerating cone mosaic by using two criteria: variable contrast on a split detector AOSLO and high reflectivity on a confocal AOSLO. CONCLUSIONS AOSLO reveals that the cone mosaic is similar to ex vivo histology. Its use as a noninvasive tool will enable observation of morphologic changes that arise in the cone mosaic of TgP23H pigs over time. TRANSLATIONAL RELEVANCE Pigs are widely used for translational studies, and the ability to noninvasively assess cellular changes in the cone mosaic will facilitate more detailed investigations of new retinal disease models as well as outcomes of potential therapies.
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Affiliation(s)
- Alison L Huckenpahler
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alexander E Salmon
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Benjamin S Sajdak
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Rebecca R Mastey
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kenneth P Allen
- Biomedical Resource Center, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Henry J Kaplan
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY, USA
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Mastey RR, Gaffney M, Litts KM, Langlo CS, Patterson EJ, Strampe MR, Kalitzeos A, Michaelides M, Carroll J. Assessing the Interocular Symmetry of Foveal Outer Nuclear Layer Thickness in Achromatopsia. Transl Vis Sci Technol 2019; 8:21. [PMID: 31602346 PMCID: PMC6779097 DOI: 10.1167/tvst.8.5.21] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/12/2019] [Indexed: 02/02/2023] Open
Abstract
Purpose We examine the interocular symmetry of foveal outer nuclear layer (ONL) thickness measurements in subjects with achromatopsia (ACHM). Methods Images from 76 subjects with CNGA3- or CNGB3-associated ACHM and 42 control subjects were included in the study. Line or volume scans through the fovea of each eye were acquired using optical coherence tomography (OCT). Image quality was assessed for each image included in the analysis using a previously-described maximum tissue contrast index (mTCI) metric. Three foveal ONL thickness measurements were made by a single observer and interocular symmetry was assessed using the average of the three measurements for each eye. Results Mean (± standard deviation) foveal ONL thickness for subjects with ACHM was 79.7 ± 18.3 μm (right eye) and 79.2 ± 18.7 μm (left eye) compared to 112.9 ± 15.2 (right eye) and 112.1 ± 13.9 μm (left eye) for controls. Foveal ONL thickness did not differ between eyes for ACHM (P = 0.636) or control subjects (P = 0.434). No significant relationship between mTCI and observer repeatability was observed for either control (P = 0.140) or ACHM (P = 0.351) images. Conclusions While foveal ONL thickness is reduced in ACHM compared to controls, the high interocular symmetry indicates that contralateral ONL measurements could be used as a negative control in early-phase monocular treatment trials. Translational Relevance Foveal ONL thickness can be measured using OCT images over a wide range of image quality. The interocular symmetry of foveal ONL thickness in ACHM and control populations supports the use of the non-study eye as a control for clinical trial purposes.
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Affiliation(s)
- Rebecca R Mastey
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mina Gaffney
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Katie M Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher S Langlo
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Emily J Patterson
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margaret R Strampe
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,University of Minnesota Medical School, Minneapolis, MN, USA
| | - Angelos Kalitzeos
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Michel Michaelides
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
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Cunefare D, Huckenpahler AL, Patterson EJ, Dubra A, Carroll J, Farsiu S. RAC-CNN: multimodal deep learning based automatic detection and classification of rod and cone photoreceptors in adaptive optics scanning light ophthalmoscope images. BIOMEDICAL OPTICS EXPRESS 2019; 10:3815-3832. [PMID: 31452977 PMCID: PMC6701534 DOI: 10.1364/boe.10.003815] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/26/2019] [Accepted: 06/29/2019] [Indexed: 05/03/2023]
Abstract
Quantification of the human rod and cone photoreceptor mosaic in adaptive optics scanning light ophthalmoscope (AOSLO) images is useful for the study of various retinal pathologies. Subjective and time-consuming manual grading has remained the gold standard for evaluating these images, with no well validated automatic methods for detecting individual rods having been developed. We present a novel deep learning based automatic method, called the rod and cone CNN (RAC-CNN), for detecting and classifying rods and cones in multimodal AOSLO images. We test our method on images from healthy subjects as well as subjects with achromatopsia over a range of retinal eccentricities. We show that our method is on par with human grading for detecting rods and cones.
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Affiliation(s)
- David Cunefare
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Alison L. Huckenpahler
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Emily J. Patterson
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sina Farsiu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
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67
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Felden J, Baumann B, Ali M, Audo I, Ayuso C, Bocquet B, Casteels I, Garcia-Sandoval B, Jacobson SG, Jurklies B, Kellner U, Kessel L, Lorenz B, McKibbin M, Meunier I, de Ravel T, Rosenberg T, Rüther K, Vadala M, Wissinger B, Stingl K, Kohl S. Mutation spectrum and clinical investigation of achromatopsia patients with mutations in the GNAT2 gene. Hum Mutat 2019; 40:1145-1155. [PMID: 31058429 DOI: 10.1002/humu.23768] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 02/04/2023]
Abstract
Achromatopsia (ACHM) is a hereditary cone photoreceptor disorder characterized by the inability to discriminate colors, nystagmus, photophobia, and low-visual acuity. Six genes have been associated with this rare autosomal recessively inherited disease, including the GNAT2 gene encoding the catalytic α-subunit of the G-protein transducin which is expressed in the cone photoreceptor outer segment. Out of a cohort of 1,116 independent families diagnosed with a primary clinical diagnosis of ACHM, we identified 23 patients with ACHM from 19 independent families with likely causative mutations in GNAT2, representing 1.7% of our large ACHM cohort. In total 22 different potentially disease-causing variants, of which 12 are novel, were identified. The mutation spectrum also includes a novel copy number variation, a heterozygous duplication of exon 4, of which the breakpoint matches exactly that of the previously reported exon 4 deletion. Two patients carry just a single heterozygous variant. In addition to our previous study on GNAT2-ACHM, we also present detailed clinical data of these patients.
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Affiliation(s)
- Julia Felden
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Manir Ali
- Section of Ophthalmology and Neuroscience, Leeds Institute of Medical Research at St. James's University Hospital, University of Leeds, Leeds, England
| | - Isabelle Audo
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institute de la Vision/ CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS, Paris, France
| | - Carmen Ayuso
- University Hospital Fundación Jiménez Díaz/Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Beatrice Bocquet
- Centre de Référence Maladies Sensorielles Génétiques, Hôpital Gui de Chauliac; Montpellier University and INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | | | - Samuel G Jacobson
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Ulrich Kellner
- Rare Retinal Disease Center, AugenZentrum Siegburg, MVZ ADTC Siegburg GmbH, Europaplatz 3, Siegburg, Germany
| | - Line Kessel
- The National Eye Clinic, Rigshospitalet, Kennedy Center, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Martin McKibbin
- Section of Ophthalmology and Neuroscience, Leeds Institute of Medical Research at St. James's University Hospital, University of Leeds, Leeds, England
| | - Isabelle Meunier
- Centre de Référence Maladies Sensorielles Génétiques, Hôpital Gui de Chauliac; Montpellier University and INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Thomy de Ravel
- Center for Human Genetics, University Hospitals Leuven, University of Leuven, Leuven, Belgium
| | - Thomas Rosenberg
- The National Eye Clinic, Rigshospitalet, Kennedy Center, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Klaus Rüther
- Augenarztpraxis, Dorotheenstrasse 56, Berlin, Germany
| | - Maria Vadala
- Ophthalmology Institute, Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata (BiND), Università degli Studi di Palermo
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
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Liu J, Jung H, Dubra A, Tam J. Cone Photoreceptor Cell Segmentation and Diameter Measurement on Adaptive Optics Images Using Circularly Constrained Active Contour Model. Invest Ophthalmol Vis Sci 2019; 59:4639-4652. [PMID: 30372733 PMCID: PMC6154284 DOI: 10.1167/iovs.18-24734] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purpose Cone photoreceptor cells can be noninvasively imaged in the living human eye by using nonconfocal adaptive optics scanning ophthalmoscopy split detection. Existing metrics, such as cone density and spacing, are based on simplifying cone photoreceptors to single points. The purposes of this study were to introduce a computer-aided approach for segmentation of cone photoreceptors, to apply this technique to create a normal database of cone diameters, and to demonstrate its use in the context of existing metrics. Methods Cone photoreceptor segmentation is achieved through a circularly constrained active contour model (CCACM). Circular templates and image gradients attract active contours toward cone photoreceptor boundaries. Automated segmentation from in vivo human subject data was compared to ground truth established by manual segmentation. Cone diameters computed from curated data (automated segmentation followed by manual removal of errors) were compared with histology and published data. Results Overall, there was good agreement between automated and manual segmentations and between diameter measurements (n = 5191 cones) and published histologic data across retinal eccentricities ranging from 1.35 to 6.35 mm (temporal). Interestingly, cone diameter was correlated to both cone density and cone spacing (negatively and positively, respectively; P < 0.01 for both). Application of the proposed automated segmentation to images from a patient with late-onset retinal degeneration revealed the presence of enlarged cones above individual reticular pseudodrusen (average 23.0% increase, P < 0.05). Conclusions CCACM can accurately segment cone photoreceptors on split detection images across a range of eccentricities. Metrics derived from this automated segmentation of adaptive optics retinal images can provide new insights into retinal diseases.
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Affiliation(s)
- Jianfei Liu
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - HaeWon Jung
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Johnny Tam
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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Patterson EJ, Kalitzeos A, Kasilian M, Gardner JC, Neitz J, Hardcastle AJ, Neitz M, Carroll J, Michaelides M. Residual Cone Structure in Patients With X-Linked Cone Opsin Mutations. Invest Ophthalmol Vis Sci 2019; 59:4238-4248. [PMID: 30128495 PMCID: PMC6103386 DOI: 10.1167/iovs.18-24699] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose To assess residual cone structure in subjects with mutations in exon 2, 3, and 4 of the OPN1LW or OPN1MW opsin. Methods Thirteen males had their OPN1LW/OPN1MW opsin genes characterized. The cone mosaic was imaged using both confocal and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO), and retinal thickness was evaluated using optical coherence tomography (OCT). Six subjects completed serial imaging over a maximum period of 18 months and cone density was measured across imaging sessions. Results Ten subjects had an OPN1LW/OPN1MW "interchange" opsin mutation designated as LIAVA or LVAVA, which both introduce exon 3 splicing defects leading to a lack of functional photopigment in cones expressing LIAVA and greatly reduced functional photopigment in cones expressing LVAVA. Despite disrupted cone reflectivity and reduced numerosity, residual inner segments could be visualized. Similar patterns were observed in individuals with an exon 2 insertion, or an exon 4 splice defect, both of which are also expected to produce cones that are devoid of functional opsin protein. OCT revealed variably reduced retinal thickness. A significant inverse relationship was found between the proportion of waveguiding cones and axial length. Conclusions Split-detection imaging revealed that the altered appearance of the cone mosaic in confocal images for subjects with exon 2, 3, and 4 mutations was generally due to disrupted waveguiding, rather than structural loss, making them possible candidates for gene therapy to restore cone function. The relative fraction of waveguiding cones was highly variable across subjects, which appears to influence emmetropization in these subjects.
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Affiliation(s)
- Emily J Patterson
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Angelos Kalitzeos
- University College London Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Melissa Kasilian
- University College London Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Jessica C Gardner
- University College London Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Jay Neitz
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Alison J Hardcastle
- University College London Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Maureen Neitz
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.,Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.,Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michel Michaelides
- University College London Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
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Georgiou M, Litts KM, Kalitzeos A, Langlo CS, Kane T, Singh N, Kassilian M, Hirji N, Kumaran N, Dubra A, Carroll J, Michaelides M. Adaptive Optics Retinal Imaging in CNGA3-Associated Achromatopsia: Retinal Characterization, Interocular Symmetry, and Intrafamilial Variability. Invest Ophthalmol Vis Sci 2019; 60:383-396. [PMID: 30682209 PMCID: PMC6354941 DOI: 10.1167/iovs.18-25880] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/21/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate retinal structure in subjects with CNGA3-associated achromatopsia and evaluate disease symmetry and intrafamilial variability. Methods Thirty-eight molecularly confirmed subjects underwent ocular examination, optical coherence tomography (OCT), and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). OCT scans were used for evaluating foveal hypoplasia, grading foveal ellipsoid zone (EZ) disruption, and measuring outer nuclear layer (ONL) thickness. AOSLO images were used to quantify peak foveal cone density, intercell distance (ICD), and the coefficient of variation (CV) of ICD. Results Mean (±SD) age was 25.9 (±13.1) years. Mean (± SD) best corrected visual acuity (BCVA) was 0.87 (±0.14) logarithm of the minimum angle of resolution. Examination with OCT showed variable disruption or loss of the EZ. Seven subjects were evaluated for disease symmetry, with peak foveal cone density, ICD, CV, ONL thickness, and BCVA not differing significantly between eyes. A cross-sectional evaluation of AOSLO imaging showed a mean (±SD) peak foveal cone density of 19,844 (±13,046) cones/mm2. There was a weak negative association between age and peak foveal cone density (r = -0.397, P = 0.102), as well as between EZ grade and age (P = 0.086). Conclusions The remnant cone mosaics were irregular and variably disrupted, with significantly lower peak foveal cone density than unaffected individuals. Variability was also seen among subjects with identical mutations. Therefore, subjects should be considered on an individual basis for stratification in clinical trials. Interocular symmetry suggests that both eyes have comparable therapeutic potential and the fellow eye can serve as a valid control. Longitudinal studies are needed, to further examine the weak negative association between age and foveal cone structure observed here.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Katie M. Litts
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Christopher S. Langlo
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Melissa Kassilian
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
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Abstract
Retinal imaging has advanced to enable noninvasive in vivo visualization of macular photoreceptors with cellular resolution. Images of retinal structure are best interpreted in the context of visual function, but clinical measures of visual function lack resolution on the scale of individual cells. Combined with cross-sectional measures of retinal structure acquired with optical coherence tomography (OCT), macular photoreceptor function can be evaluated using visual acuity and fundus-guided microperimetry, but the resolution of these measures is limited to relatively large retinal areas. By incorporating adaptive optics correction of aberrations in light entering and exiting the pupil, individual photoreceptors can be visualized and stimulated to assess structure and function. Discrepancy between structural images and visual function can shed light on the origin of visible features and their relation to visual function. Dysflective cones, cones with abnormal waveguiding properties on confocal adaptive optics scanning laser ophthalmoscopy (AOSLO) images and measurable function, provide insight into the visual significance of features in retinal images and may facilitate identification of patients who could benefit from therapies.
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Affiliation(s)
- Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA, USA.
| | - Austin Roorda
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, CA, USA
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72
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Burns SA, Elsner AE, Sapoznik KA, Warner RL, Gast TJ. Adaptive optics imaging of the human retina. Prog Retin Eye Res 2019; 68:1-30. [PMID: 30165239 PMCID: PMC6347528 DOI: 10.1016/j.preteyeres.2018.08.002] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/18/2022]
Abstract
Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From animal models to clinical patients, AO imaging is changing the way scientists are approaching the study of the retina. By providing cellular and subcellular details without the need for histology, it is now possible to perform large scale studies as well as to understand how an individual retina changes over time. Because AO retinal imaging is non-invasive and when performed with near-IR wavelengths both safe and easily tolerated by patients, it holds promise for being incorporated into clinical trials providing cell specific approaches to monitoring diseases and therapeutic interventions. AO is being used to enhance the ability of OCT, fluorescence imaging, and reflectance imaging. By incorporating imaging that is sensitive to differences in the scattering properties of retinal tissue, it is especially sensitive to disease, which can drastically impact retinal tissue properties. This review examines human AO retinal imaging with a concentration on the use of the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). It first covers the background and the overall approaches to human AO retinal imaging, and the technology involved, and then concentrates on using AO retinal imaging to study the structure and function of the retina.
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Affiliation(s)
- Stephen A Burns
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States.
| | - Ann E Elsner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Kaitlyn A Sapoznik
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Raymond L Warner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Thomas J Gast
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
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73
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Walters S, Schwarz C, Sharma R, Rossi EA, Fischer WS, DiLoreto DA, Strazzeri J, Nelidova D, Roska B, Hunter JJ, Williams DR, Merigan WH. Cellular-scale evaluation of induced photoreceptor degeneration in the living primate eye. BIOMEDICAL OPTICS EXPRESS 2019; 10:66-82. [PMID: 30775083 PMCID: PMC6363191 DOI: 10.1364/boe.10.000066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 05/06/2023]
Abstract
Progress is needed in developing animal models of photoreceptor degeneration and evaluating such models with longitudinal, noninvasive techniques. We employ confocal scanning laser ophthalmoscopy, optical coherence tomography (OCT) and high-resolution retinal imaging to noninvasively observe the retina of non-human primates with induced photoreceptor degeneration. Photoreceptors were imaged at the single-cell scale in three modalities of adaptive optics scanning light ophthalmoscopy: traditional confocal reflectance, indicative of waveguiding; a non-confocal offset aperture technique visualizing scattered light; and two-photon excited fluorescence, the time-varying signal of which, at 730 nm excitation, is representative of visual cycle function. Assessment of photoreceptor structure and function using these imaging modalities revealed a reduction in retinoid production in cone photoreceptor outer segments while inner segments appeared to remain present. Histology of one retina confirmed loss of outer segments and the presence of intact inner segments. This unique combination of imaging modalities can provide essential, clinically-relevant information on both the structural integrity and function of photoreceptors to not only validate models of photoreceptor degeneration but potentially evaluate the efficacy of future cell and gene-based therapies for vision restoration.
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Affiliation(s)
- Sarah Walters
- The Institute of Optics, University of Rochester, Rochester, NY, USA
- Center for Visual Science, University of Rochester, Rochester, NY, USA
| | - Christina Schwarz
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Currently with the Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Robin Sharma
- The Institute of Optics, University of Rochester, Rochester, NY, USA
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Currently with Facebook Reality Labs, Redmond, WA, USA
| | - Ethan A. Rossi
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Currently with the Departments of Ophthalmology & Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Jennifer Strazzeri
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
| | - Dasha Nelidova
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Botond Roska
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jennifer J. Hunter
- The Institute of Optics, University of Rochester, Rochester, NY, USA
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - David R. Williams
- The Institute of Optics, University of Rochester, Rochester, NY, USA
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
| | - William H. Merigan
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
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Lee DJ, Woertz EN, Visotcky A, Wilk MA, Heitkotter H, Linderman RE, Tarima S, Summers CG, Brooks BP, Brilliant MH, Antony BJ, Lujan BJ, Carroll J. The Henle Fiber Layer in Albinism: Comparison to Normal and Relationship to Outer Nuclear Layer Thickness and Foveal Cone Density. Invest Ophthalmol Vis Sci 2018; 59:5336-5348. [PMID: 30398625 PMCID: PMC6219160 DOI: 10.1167/iovs.18-24145] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/24/2018] [Indexed: 12/31/2022] Open
Abstract
Purpose Directional optical coherence tomography (D-OCT) allows the visualization of the Henle fiber layer (HFL) in vivo. Here, we used D-OCT to characterize the HFL and outer nuclear layer (ONL) in albinism and examine the relationship between true foveal ONL and peak cone density. Methods Horizontal D-OCT B-scans were acquired, registered, and averaged for 12 subjects with oculocutaneous albinism and 26 control subjects. Averaged images were manually segmented to extract HFL and ONL thickness. Adaptive optics scanning light ophthalmoscopy was used to acquire images of the foveal cone mosaic in 10 subjects with albinism, from which peak cone density was assessed. Results Across the foveal region, the HFL topography was different between subjects with albinism and normal controls. In particular, foveal HFL thickness was thicker in albinism than in normal controls (P < 0.0001), whereas foveal ONL thickness was thinner in albinism than in normal controls (P < 0.0001). The total HFL and ONL thickness was not significantly different between albinism and controls (P = 0.3169). Foveal ONL thickness was positively correlated with peak cone density in subjects with albinism (r = 0.8061, P = 0.0072). Conclusions Foveal HFL and ONL topography are significantly altered in albinism relative to normal controls. Our data suggest that increased foveal cone packing drives the formation of Henle fibers, more so than the lateral displacement of inner retinal neurons (which is reduced in albinism). The ability to quantify foveal ONL and HFL may help further stratify grading schemes used to assess foveal hypoplasia.
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Affiliation(s)
- Daniel J. Lee
- Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Erica N. Woertz
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Alexis Visotcky
- Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Melissa A. Wilk
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States
| | - Heather Heitkotter
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Rachel E. Linderman
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sergey Tarima
- Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - C. Gail Summers
- Department of Ophthalmology & Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
| | | | - Murray H. Brilliant
- Center for Human Genetics, Marshfield Clinic Research Institute, Marshfield, Wisconsin, United States
| | | | - Brandon J. Lujan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Joseph Carroll
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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75
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Cunefare D, Langlo CS, Patterson EJ, Blau S, Dubra A, Carroll J, Farsiu S. Deep learning based detection of cone photoreceptors with multimodal adaptive optics scanning light ophthalmoscope images of achromatopsia. BIOMEDICAL OPTICS EXPRESS 2018; 9:3740-3756. [PMID: 30338152 PMCID: PMC6191607 DOI: 10.1364/boe.9.003740] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/15/2018] [Accepted: 07/15/2018] [Indexed: 05/18/2023]
Abstract
Fast and reliable quantification of cone photoreceptors is a bottleneck in the clinical utilization of adaptive optics scanning light ophthalmoscope (AOSLO) systems for the study, diagnosis, and prognosis of retinal diseases. To-date, manual grading has been the sole reliable source of AOSLO quantification, as no automatic method has been reliably utilized for cone detection in real-world low-quality images of diseased retina. We present a novel deep learning based approach that combines information from both the confocal and non-confocal split detector AOSLO modalities to detect cones in subjects with achromatopsia. Our dual-mode deep learning based approach outperforms the state-of-the-art automated techniques and is on a par with human grading.
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Affiliation(s)
- David Cunefare
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Christopher S. Langlo
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Emily J. Patterson
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sarah Blau
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sina Farsiu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
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76
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Lu J, Gu B, Wang X, Zhang Y. High speed adaptive optics ophthalmoscopy with an anamorphic point spread function. OPTICS EXPRESS 2018; 26:14356-14374. [PMID: 29877476 PMCID: PMC6005671 DOI: 10.1364/oe.26.014356] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/11/2018] [Indexed: 05/04/2023]
Abstract
Retinal imaging working with a line scan mechanism and a line camera has the potential to image the eye with a near-confocal performance at the high frame rate, but this regime has difficulty to collect sufficient imaging light while adequately digitize the optical resolution in adaptive optics imaging. To meet this challenge, we have developed an adaptive optics line scan ophthalmoscope with an anamorphic point spread function. The instrument uses a high-speed line camera to acquire the retinal image and act as a confocal gate. Meanwhile, it employs a digital micro-mirror device to modulate the imaging light into a line of point sources illuminating the retina. The anamorphic mechanism ensures adequate digitization of the optical resolution and increases light collecting efficiency. We demonstrate imaging of the living human retina with cellular level resolution at a frame rate of 200 frames/second (FPS) with a digitization of 512 × 512 pixels over a field of view of 1.2° × 1.2°. We have assessed cone photoreceptor structure in images acquired at 100, 200, and 800 FPS in 2 normal human subjects, and confirmed that retinal images acquired at high speed rendered macular cone mosaic with improved measurement repeatability.
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77
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Sajdak BS, Bell BA, Lewis TR, Luna G, Cornwell GS, Fisher SK, Merriman DK, Carroll J. Assessment of Outer Retinal Remodeling in the Hibernating 13-Lined Ground Squirrel. Invest Ophthalmol Vis Sci 2018; 59:2538-2547. [PMID: 29847661 PMCID: PMC5967598 DOI: 10.1167/iovs.17-23120] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 04/20/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose We examined outer retinal remodeling of the euthermic and torpid cone-dominant 13-lined ground squirrel (13-LGS) retina using optical coherence tomography (OCT) imaging and histology. Methods Retinas and corneas of living 13-LGSs were imaged during euthermic and torpid physiological states using OCT. Retinal layer thickness was measured at the visual streak from registered and averaged vertical B-scans. Following OCT, some retinas were collected immediately for postmortem histologic comparison using light microscopy, immunofluorescence, or transmission electron microscopy. Results Compared to OCT images from euthermic retinae, OCT images of torpid retinae revealed significantly thicker inner and outer nuclear layers, as well as increases in the distances between outer retinal reflectivity bands 1 and 2, and bands 3 and 4. A significant decrease in the distance between bands 2 and 3 also was seen, alongside significant thinning of the choriocapillaris and choroid. OCT image quality was reduced in torpid eyes, partly due to significant thickening of the corneal stroma during this state. Conclusions The torpid retina of the hibernating 13-LGS undergoes structural changes that can be detected by OCT imaging. Comparisons between in vivo OCT and ex vivo histomorphometry may offer insight to the origin of hyperreflective OCT bands within the outer retina of the cone-dominant 13-LGS.
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Affiliation(s)
- Benjamin S. Sajdak
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Brent A. Bell
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States
| | - Tylor R. Lewis
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Gabriel Luna
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Grayson S. Cornwell
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Steven K. Fisher
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Dana K. Merriman
- Biology & Microbiology, University of Wisconsin Oshkosh, Oshkosh, Wisconsin, United States
| | - Joseph Carroll
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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78
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Sapoznik KA, Luo T, de Castro A, Sawides L, Warner RL, Burns SA. Enhanced retinal vasculature imaging with a rapidly configurable aperture. BIOMEDICAL OPTICS EXPRESS 2018. [PMID: 29541524 PMCID: PMC5846534 DOI: 10.1364/boe.9.001323] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In adaptive optics scanning laser ophthalmoscope (AOSLO) systems, capturing multiply scattered light can increase the contrast of the retinal microvasculature structure, cone inner segments, and retinal ganglion cells. Current systems generally use either a split detector or offset aperture approach to collect this light. We tested the ability of a spatial light modulator (SLM) as a rapidly configurable aperture to use more complex shapes to enhance the contrast of retinal structure. Particularly, we varied the orientation of a split detector aperture and explored the use of a more complex shape, the half annulus, to enhance the contrast of the retinal vasculature. We used the new approach to investigate the influence of scattering distance and orientation on vascular imaging.
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Hirji N, Aboshiha J, Georgiou M, Bainbridge J, Michaelides M. Achromatopsia: clinical features, molecular genetics, animal models and therapeutic options. Ophthalmic Genet 2018; 39:149-157. [PMID: 29303385 DOI: 10.1080/13816810.2017.1418389] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Achromatopsia is an autosomal recessive condition, characterised by reduced visual acuity, impaired colour vision, photophobia and nystagmus. The symptoms can be profoundly disabling, and there is no cure currently available. However, the recent development of gene-based interventions may lead to improved outcomes in the future. This article aims to provide a comprehensive review of the clinical features of the condition, its genetic basis and the underlying pathogenesis. We also explore the insights derived from animal models, including the implications for gene supplementation approaches. Finally, we discuss current human gene therapy trials.
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Affiliation(s)
- Nashila Hirji
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Jonathan Aboshiha
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Michalis Georgiou
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - James Bainbridge
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Michel Michaelides
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
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Abstract
Foveal hypoplasia is a retinal disorder in which there is a lack of full development of the morphology of the fovea. The optical coherence tomography (OCT) and functional findings are presented in relation to the underlying genetic and developmental conditions. Recent advancements of high-resolution OCT imaging have unveiled characteristics of foveal hypoplasia that were not detected by conventional imaging methods. An absence of a foveal pit does not necessarily imply poor visual acuity, and the maturation of the cone photoreceptors is important for the visual acuity. Regardless of the degree of the development of the inner retinal layers, the visual acuity can be preserved as in diseases such as Stickler syndrome that is a newly identified retinal disorder associated with foveal hypoplasia.
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Affiliation(s)
- Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health, Kitakyushu, Japan
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81
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Hassall MM, Barnard AR, MacLaren RE. Gene Therapy for Color Blindness. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2017; 90:543-551. [PMID: 29259520 PMCID: PMC5733843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Achromatopsia is a rare congenital cause of vision loss due to isolated cone photoreceptor dysfunction. The most common underlying genetic mutations are autosomal recessive changes in CNGA3, CNGB3, GNAT2, PDE6H, PDE6C, or ATF6. Animal models of Cnga3, Cngb3, and Gnat2 have been rescued using AAV gene therapy; showing partial restoration of cone electrophysiology and integration of this new photopic vision in reflexive and behavioral visual tests. Three gene therapy phase I/II trials are currently being conducted in human patients in the USA, the UK, and Germany. This review details the AAV gene therapy treatments of achromatopsia to date. We also present novel data showing rescue of a Cnga3-/- mouse model using an rAAV.CBA.CNGA3 vector. We conclude by synthesizing the implications of this animal work for ongoing human trials, particularly, the challenge of restoring integrated cone retinofugal pathways in an adult visual system. The evidence to date suggests that gene therapy for achromatopsia will need to be applied early in childhood to be effective.
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Affiliation(s)
- Mark M. Hassall
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK,To whom all correspondence should be addressed: Dr. Mark M. Hassall, Nuffield Laboratory of Ophthalmology, Level 6, West Wing, John Radcliffe Hospital, Headley Way, Oxford, UK, OX3 9DU, Tel: +44 1865 234768, .
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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82
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Georgiou M, Kalitzeos A, Patterson EJ, Dubra A, Carroll J, Michaelides M. Adaptive optics imaging of inherited retinal diseases. Br J Ophthalmol 2017; 102:1028-1035. [PMID: 29141905 PMCID: PMC6059037 DOI: 10.1136/bjophthalmol-2017-311328] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/23/2017] [Accepted: 11/04/2017] [Indexed: 12/17/2022]
Abstract
Adaptive optics (AO) ophthalmoscopy allows for non-invasive retinal phenotyping on a microscopic scale, thereby helping to improve our understanding of retinal diseases. An increasing number of natural history studies and ongoing/planned interventional clinical trials exploit AO ophthalmoscopy both for participant selection, stratification and monitoring treatment safety and efficacy. In this review, we briefly discuss the evolution of AO ophthalmoscopy, recent developments and its application to a broad range of inherited retinal diseases, including Stargardt disease, retinitis pigmentosa and achromatopsia. Finally, we describe the impact of this in vivo microscopic imaging on our understanding of disease pathogenesis, clinical trial design and outcome metrics, while recognising the limitation of the small cohorts reported to date.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Emily J Patterson
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Langlo CS, Erker LR, Parker M, Patterson EJ, Higgins BP, Summerfelt P, Razeen MM, Collison FT, Fishman GA, Kay CN, Zhang J, Weleber RG, Yang P, Pennesi ME, Lam BL, Chulay JD, Dubra A, Hauswirth WW, Wilson DJ, Carroll J. REPEATABILITY AND LONGITUDINAL ASSESSMENT OF FOVEAL CONE STRUCTURE IN CNGB3-ASSOCIATED ACHROMATOPSIA. Retina 2017; 37:1956-1966. [PMID: 28145975 PMCID: PMC5537050 DOI: 10.1097/iae.0000000000001434] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia. METHODS Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed. RESULTS ONL thickness increased slightly compared with baseline (0.184 μm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126). CONCLUSION Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.
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Affiliation(s)
- Christopher S. Langlo
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Laura R. Erker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Maria Parker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Emily J. Patterson
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Brian P. Higgins
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Phyllis Summerfelt
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Moataz M. Razeen
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Frederick T. Collison
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois
| | - Gerald A. Fishman
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois
| | | | - Jing Zhang
- Vitreo Retinal Associates, Gainesville, Florida
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida
| | | | - Alfredo Dubra
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | | | - David J. Wilson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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84
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Maguire J, McKibbin M, Khan K, Kohl S, Ali M, McKeefry D. CNGB3 mutations cause severe rod dysfunction. Ophthalmic Genet 2017; 39:108-114. [PMID: 28929832 DOI: 10.1080/13816810.2017.1368087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Congenital achromatopsia or rod monochromatism is a rare autosomal recessive condition defined by a severe loss of cone photoreceptor function in which rods purportedly retain normal or near-to-normal function. This report describes the results of electroretinography in two siblings with CNGB3-associated achromatopsia. METHODS Full field light- and dark-adapted electroretinograms (ERGs) were recorded using standard protocols detailed by the International Society for Clinical Electrophysiology of Vision (ISCEV). We also examined rod-mediated ERGs using series of stimuli that varied over a 6 log unit range of retinal illuminances (-1.9-3.5 log scotopic trolands). RESULTS Dark-adapted ERGs in achromatopsia patients exhibited severely reduced b-wave amplitudes with abnormal b:a ratios (1.3 and 0.6). In comparison, the reduction in a-wave amplitude was less marked. The rod-mediated ERG took on an electronegative appearance at high-stimulus illuminances. CONCLUSION Although the defect that causes achromatopsia is primarily in the cone photoreceptors, our results reveal an accompanying disruption of rod function that is more severe than has previously been reported. The differential effects on the b-wave relative to the a-wave points to an inner-retinal locus for the disruption of rod function in these patients.
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Affiliation(s)
- J Maguire
- a School of Optometry and Vision Sciences , University of Bradford , Bradford , West Yorkshire , UK
| | - M McKibbin
- b Department of Ophthalmology , St. James's University Teaching Hospital , Leeds , UK
| | - K Khan
- b Department of Ophthalmology , St. James's University Teaching Hospital , Leeds , UK
| | - S Kohl
- c Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre of Ophthalmology , University Clinics Tubingen , Tubingen , Germany
| | - M Ali
- d Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences , University of Leeds , Leeds , UK
| | - D McKeefry
- a School of Optometry and Vision Sciences , University of Bradford , Bradford , West Yorkshire , UK
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85
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Mayer AK, Van Cauwenbergh C, Rother C, Baumann B, Reuter P, De Baere E, Wissinger B, Kohl S. CNGB3 mutation spectrum including copy number variations in 552 achromatopsia patients. Hum Mutat 2017; 38:1579-1591. [PMID: 28795510 DOI: 10.1002/humu.23311] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/25/2017] [Accepted: 08/04/2017] [Indexed: 02/03/2023]
Abstract
Achromatopsia is a rare autosomal recessive cone disorder characterized by color vision defects, photophobia, nystagmus, and severely reduced visual acuity. The disease is caused by mutations in genes encoding crucial components of the cone phototransduction cascade (CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H) or in ATF6, involved in the unfolded protein response. CNGB3 encoding the beta subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors is the major achromatopsia gene. Here, we present a comprehensive spectrum of CNGB3 mutations and their prevalence in a cohort of 1074 independent families clinically diagnosed with achromatopsia. Of these, 485 (45.2%) carried mutations in CNGB3. We identified a total of 98 different potentially disease-causing CNGB3 variants, 58 of which are novel. About 10% of patients with CNGB3 mutations only harbored a single heterozygous variant. Therefore, we performed quantitative real-time PCR in 43 of such single heterozygotes in search of the missing allele, followed by microarray-based comparative genomic hybridization and breakpoint mapping. We discovered nine different heterozygous copy number variations encompassing one to 10 consecutive exons in 16 unrelated patients. Moreover, one additional patient with a homozygous CNGB3 deletion encompassing exons 4-18 was identified, highlighting the importance of CNV analysis for this gene.
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Affiliation(s)
- Anja K Mayer
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Christine Rother
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Britta Baumann
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Peggy Reuter
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
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86
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Litts KM, Cooper RF, Duncan JL, Carroll J. Photoreceptor-Based Biomarkers in AOSLO Retinal Imaging. Invest Ophthalmol Vis Sci 2017; 58:BIO255-BIO267. [PMID: 28873135 PMCID: PMC5584616 DOI: 10.1167/iovs.17-21868] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/28/2017] [Indexed: 01/08/2023] Open
Abstract
Improved understanding of the mechanisms underlying inherited retinal degenerations has created the possibility of developing much needed treatments for these relentless, blinding diseases. However, standard clinical indicators of retinal health (such as visual acuity and visual field sensitivity) are insensitive measures of photoreceptor survival. In many retinal degenerations, significant photoreceptor loss must occur before measurable differences in visual function are observed. Thus, there is a recognized need for more sensitive outcome measures to assess therapeutic efficacy as numerous clinical trials are getting underway. Adaptive optics (AO) retinal imaging techniques correct for the monochromatic aberrations of the eye and can be used to provide nearly diffraction-limited images of the retina. Many groups routinely are using AO imaging tools to obtain in vivo images of the rod and cone photoreceptor mosaic, and it now is possible to monitor photoreceptor structure over time with single cell resolution. Highlighting recent work using AO scanning light ophthalmoscopy (AOSLO) across a range of patient populations, we review the development of photoreceptor-based metrics (e.g., density/geometry, reflectivity, and size) as candidate biomarkers. Going forward, there is a need for further development of automated tools and normative databases, with the latter facilitating the comparison of data sets across research groups and devices. Ongoing and future clinical trials for inherited retinal diseases will benefit from the improved resolution and sensitivity that multimodal AO retinal imaging affords to evaluate safety and efficacy of emerging therapies.
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Affiliation(s)
- Katie M. Litts
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Robert F. Cooper
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Jacque L. Duncan
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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87
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Salmon AE, Cooper RF, Langlo CS, Baghaie A, Dubra A, Carroll J. An Automated Reference Frame Selection (ARFS) Algorithm for Cone Imaging with Adaptive Optics Scanning Light Ophthalmoscopy. Transl Vis Sci Technol 2017; 6:9. [PMID: 28392976 PMCID: PMC5381332 DOI: 10.1167/tvst.6.2.9] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/28/2017] [Indexed: 01/12/2023] Open
Abstract
PURPOSE To develop an automated reference frame selection (ARFS) algorithm to replace the subjective approach of manually selecting reference frames for processing adaptive optics scanning light ophthalmoscope (AOSLO) videos of cone photoreceptors. METHODS Relative distortion was measured within individual frames before conducting image-based motion tracking and sorting of frames into distinct spatial clusters. AOSLO images from nine healthy subjects were processed using ARFS and human-derived reference frames, then aligned to undistorted AO-flood images by nonlinear registration and the registration transformations were compared. The frequency at which humans selected reference frames that were rejected by ARFS was calculated in 35 datasets from healthy subjects, and subjects with achromatopsia, albinism, or retinitis pigmentosa. The level of distortion in this set of human-derived reference frames was assessed. RESULTS The average transformation vector magnitude required for registration of AOSLO images to AO-flood images was significantly reduced from 3.33 ± 1.61 pixels when using manual reference frame selection to 2.75 ± 1.60 pixels (mean ± SD) when using ARFS (P = 0.0016). Between 5.16% and 39.22% of human-derived frames were rejected by ARFS. Only 2.71% to 7.73% of human-derived frames were ranked in the top 5% of least distorted frames. CONCLUSION ARFS outperforms expert observers in selecting minimally distorted reference frames in AOSLO image sequences. The low success rate in human frame choice illustrates the difficulty in subjectively assessing image distortion. TRANSLATIONAL RELEVANCE Manual reference frame selection represented a significant barrier to a fully automated image-processing pipeline (including montaging, cone identification, and metric extraction). The approach presented here will aid in the clinical translation of AOSLO imaging.
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Affiliation(s)
- Alexander E Salmon
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Robert F Cooper
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA ; Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Christopher S Langlo
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ahmadreza Baghaie
- Department of Electrical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Alfredo Dubra
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA ; Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA ; Current affiliation: Department of Ophthalmology, Stanford University, 2452 Watson Court, Palo Alto, CA, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA ; Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
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Evaluating outer segment length as a surrogate measure of peak foveal cone density. Vision Res 2016; 130:57-66. [PMID: 27887888 DOI: 10.1016/j.visres.2016.10.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/16/2016] [Accepted: 10/17/2016] [Indexed: 11/22/2022]
Abstract
Adaptive optics (AO) imaging tools enable direct visualization of the cone photoreceptor mosaic, which facilitates quantitative measurements such as cone density. However, in many individuals, low image quality or excessive eye movements precludes making such measures. As foveal cone specialization is associated with both increased density and outer segment (OS) elongation, we sought to examine whether OS length could be used as a surrogate measure of foveal cone density. The retinas of 43 subjects (23 normal and 20 albinism; aged 6-67years) were examined. Peak foveal cone density was measured using confocal adaptive optics scanning light ophthalmoscopy (AOSLO), and OS length was measured using optical coherence tomography (OCT) and longitudinal reflectivity profile-based approach. Peak cone density ranged from 29,200 to 214,000cones/mm2 (111,700±46,300cones/mm2); OS length ranged from 26.3 to 54.5μm (40.5±7.7μm). Density was significantly correlated with OS length in albinism (p<0.0001), but not normals (p=0.99). A cubic model of density as a function of OS length was created based on histology and optimized to fit the albinism data. The model includes triangular cone packing, a cylindrical OS with a fixed volume of 136.6μm3, and a ratio of OS to inner segment width that increased linearly with increasing OS length (R2=0.72). Normal subjects showed no apparent relationship between cone density and OS length. In the absence of adequate AOSLO imagery, OS length may be used to estimate cone density in patients with albinism. Whether this relationship exists in other patient populations with foveal hypoplasia (e.g., premature birth, aniridia, isolated foveal hypoplasia) remains to be seen.
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