Automated Segmentation of Autofluorescence Lesions in Stargardt Disease.

OBJECTIVE: To train a deep learning (DL) algorithm to perform fully automated semantic segmentation of multiple autofluorescence lesion types in Stargardt disease. DESIGN: Cross-sectional study with retrospective imaging data. SUBJECTS: The study included 193 images from 193 eyes of 97 patients with Stargardt disease. METHODS: Fundus autofluorescence images obtained from patient visits between 2013 and 2020 were annotated with ground-truth labels. Model training and evaluation were performed using fivefold cross-validation. MAIN OUTCOMES MEASURES: Dice similarity coefficients, intraclass correlation coefficients, and Bland-Altman analyses comparing algorithm-predicted and grader-labeled segmentations. RESULTS: The overall Dice similarity coefficient across all lesion classes was 0.78 (95% confidence interval [CI], 0.69-0.86). Dice coefficients were 0.90 (95% CI, 0.85-0.94) for areas of definitely decreased autofluorescence (DDAF), 0.55 (95% CI, 0.35-0.76) for areas of questionably decreased autofluorescence (QDAF), and 0.88 (95% CI, 0.73-1.00) for areas of abnormal background autofluorescence (ABAF). Intraclass correlation coefficients comparing the ground-truth and automated methods were 0.997 (95% CI, 0.996-0.998) for DDAF, 0.863 (95% CI, 0.823-0.895) for QDAF, and 0.974 (95% CI, 0.966-0.980) for ABAF. CONCLUSIONS: A DL algorithm performed accurate segmentation of autofluorescence lesions in Stargardt disease, demonstrating the feasibility of fully automated segmentation as an alternative to manual or semiautomated labeling methods.

Real-world outcomes of voretigene neparvovec treatment in pediatric patients with RPE65-associated Leber congenital amaurosis.

PURPOSE: To investigate real-world safety and efficacy of voretigene neparvovec gene therapy administration in pediatric patients with biallelic RPE65 disease-causing variants. METHODS: A retrospective study of 27 eyes of 14 patients with RPE65-associated Leber congenital amaurosis examined postoperative complications and longitudinal changes in photoreceptor function following treatment with subretinal injection of voretigene neparvovec. Full-field stimulus threshold testing (FST), Goldmann visual fields (GVF), best-corrected visual acuity (BCVA), and central subfield thickness (CST) on optical coherence tomography (OCT) scans were collected preoperatively and up to 12 months posttreatment. RESULTS: Baseline through 6-12 month follow-up FST and GVF data were obtained for 13 eyes of 7 patients. FST improved for each eye after treatment with a mean improvement of 2.1 log-units (P < 0.001) and GVF improved for each eye with a mean improvement of 221 sum degrees (P < 0.001). BCVA improved from logMAR 0.98 at baseline to logMAR 0.83 at last follow-up (P < 0.001). Across 19 eyes of 10 patients included in CST analysis, there was a small but statistically significant 9-µ decrease in mean CST from baseline to last follow-up (P < 0.001). The most common postoperative issues included elevation in intraocular pressure (59%), persistent intraocular inflammation (15%), and vitreous opacities (26%) that resolved over a period of months. CONCLUSIONS: This report provides some of the earliest longitudinal real-world evidence of the pediatric safety and efficacy of voretigene neparvovec using multiple functional and structural measures of the retina. Outcomes demonstrate significant improvements in visual function consistent with clinical trial results.

Association of No-Cost Genetic Testing Program Implementation and Patient Characteristics With Access to Genetic Testing for Inherited Retinal Degenerations.

IMPORTANCE: The benefits of no-cost genetic testing initiatives have not been characterized. The no-cost My Retina Tracker Genetic Testing Study (MRT-GTS) research registry for inherited retinal degenerations (IRDs) was launched in 2017 in the US. OBJECTIVE: To investigate the associations of MRT-GTS implementation and patient characteristics with access to genetic testing for IRDs. DESIGN, SETTING, AND PARTICIPANTS: In a cross-sectional design, analysis of new patients evaluated 12 months before (July 1, 2016, to June 13, 2017) and 12 months after (June 14, 2017, to June 30, 2018) MRT-GTS implementation at a single academic referral eye center was conducted. Participants included 369 patients with IRD. Data analysis was conducted from February to June 2020. MAIN OUTCOMES AND MEASURES: Change in rates of successfully obtaining genetic testing, odds ratios (ORs) of association between patient characteristics and obtaining testing, and days elapsed from clinic visit to reporting of results. RESULTS: Among 369 patients (mean [SD] age, 39.5 [20.8] years; 193 [52.3%] women), 144 were evaluated in the pre-MRT-GTS period and 225 in the post-MRT-GTS period. The baseline rate of successfully obtaining testing was 51.4% (95% CI, 42.6%-60.2%). The initiation of MRT-GTS was associated with a 28.9-percentage point increase in testing rate (95% CI, 16.7%-41.1%; P < .001). Patient characteristics that increased the odds of obtaining testing were eligibility for MRT-GTS (OR, 14.15; 95% CI, 7.36-27.24; P < .001) and worse visual acuity (logMAR +1.0; Snellen equivalent decrease from 20/20 to 20/200) in the better-seeing eye (OR, 1.92; 95% CI, 1.27-2.91; P < .01). Patients had decreased odds when identifying as Black or African American (OR, 0.10; 95% CI, 0.04-0.24; P < .001) or other race (OR, 0.37; 95% CI, 0.15-0.91; P = .03) compared with White race, and when the primary language was not English (OR, 0.13; 95% CI, 0.03-0.55; P < .01). The proportion of test results reported within 90 days was 81.5% (95% CI, 74.8%-86.4%) when eligible for MRT-GTS compared with 48.1% (95% CI, 35.6%-58.1%) when not eligible (P < .001). CONCLUSIONS AND RELEVANCE: In this study, the implementation of MRT-GTS was associated with an increase in the proportion of patients who successfully obtained testing, suggesting the potential clinical value of this approach. Patient-level demographic and clinical factors appear to be associated with decisions to pursue testing.

Genetic testing for inherited retinal degenerations: Triumphs and tribulations.

Inherited retinal degenerations (IRDs) are a genotypically and phenotypically diverse group of conditions. Great strides have been made toward identifying the genetic basis for these conditions over the last 30 years-more than 270 different genes involved in syndromic and nonsyndromic forms of retinal dystrophies have now been identified. The identification of these genes and the improvement of clinical laboratory techniques have led to the identification of the genetic basis of disease in 56-76% of patients with IRDs through next generation sequencing and copy number variant analysis. Genetic testing is an essential part of clinical care for patients affected with IRDs and is required to confirm the diagnosis, understand the inheritance of the condition, and determine eligibility for gene-specific treatments or clinical trials. Despite the success achieved in determining the genetic cause of these conditions, several challenges remain, which must be considered when providing genetic testing and genetic counseling to patients. For this reason, an integrated team of ophthalmic and genetic clinicians who are familiar with these challenges is necessary to provide optimal comprehensive care to these patients.

Copy-number variation contributes 9% of pathogenicity in the inherited retinal degenerations.

PURPOSE: Current sequencing strategies can genetically solve 55-60% of inherited retinal degeneration (IRD) cases, despite recent progress in sequencing. This can partially be attributed to elusive pathogenic variants (PVs) in known IRD genes, including copy-number variations (CNVs), which have been shown as major contributors to unsolved IRD cases. METHODS: Five hundred IRD patients were analyzed with targeted next-generation sequencing (NGS). The NGS data were used to detect CNVs with ExomeDepth and gCNV and the results were compared with CNV detection with a single-nucleotide polymorphism (SNP) array. Likely causal CNV predictions were validated by quantitative polymerase chain reaction (qPCR). RESULTS: Likely disease-causing single-nucleotide variants (SNVs) and small indels were found in 55.6% of subjects. PVs in USH2A (11.6%), RPGR (4%), and EYS (4%) were the most common. Likely causal CNVs were found in an additional 8.8% of patients. Of the three CNV detection methods, gCNV showed the highest accuracy. Approximately 30% of unsolved subjects had a single likely PV in a recessive IRD gene. CONCLUSION: CNV detection using NGS-based algorithms is a reliable method that greatly increases the genetic diagnostic rate of IRDs. Experimentally validating CNVs helps estimate the rate at which IRDs might be solved by a CNV plus a more elusive variant.

Macular hyperpigmentary changes in ABCA4-Stargardt disease.

BACKGROUND: Stargardt disease (STGD) and age-related macular degeneration (AMD) share clinical and pathophysiological features. In AMD, macular hyperpigmentary changes are associated to a worse prognosis. The purpose of this study was to characterize macular hyperpigmentary changes in patients with STGD and associate them with the severity of phenotype. MATERIALS AND METHODS: This retrospective cross-sectional study included 141 patients with STGD. Hyperpigmentary changes were evaluated on color fundus photography and spectral-domain optical coherence tomography. Severity of phenotype was assessed by full-field electroretinogram (ffERG) and fundus autofluorescence (FAF) patterns, and visual acuity (VA). RESULTS: Thirty patients (21.7%) showed macular hyperpigmentary changes in four distinct patterns. Out of seventeen patients who had follow-up images, eleven patients demonstrated increases of the hyperpigmented lesions, and progression of the underlying RPE atrophy overtime. VA remained stable. Of 28 patients who had ffERG, 17 patients presented with reduction of photopic and scotopic responses, while 8 presented with reduction of photopic responses only, and 3 presented with preserved photopic and scotopic responses. Of 25 patients who had FAF available, 12 presented with widespread disease extending anteriorly to the vascular arcades, while eight presented with widespread disease, extending beyond the vascular arcades, and 5 presented with disease confined to the foveal area. CONCLUSION: In this study, we demonstrated that patients with STGD with macular hyperpigmented lesions had a severe phenotype. Overtime, hyperpigmented lesions increased in size, spread across the retina, and migrated to different retinal layers. Macular hyperpigmentation may be a marker of advanced stage of the disease.

Contrast sensitivity deficits in patients with mutation-proven inherited retinal degenerations.

BACKGROUND: Patients with retinal diseases frequently complain of poor visual function even when visual acuity is relatively unaffected. This clinical finding has been attributed to deficits in contrast sensitivity (CS). The purpose of our study was to evaluate the CS in patients with clinical and genetic diagnosis of inherited retinal degeneration (IRD) and relatively preserved visual acuity. METHODS: Seventeen patients (30 eyes) with IRD and visual acuity of 20/40 or better, and 18 controls (18 eyes) without any ocular condition underwent slit lamp examination, visual acuity testing via standard Snellen chart testing, CS testing via the Quick Contrast Sensitivity Function (QCSF), and Spectral Domain Optical Coherence Tomography (SD-OCT). CS were measured at 1.0, 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). T tests with general estimated equations were used to compare CS between groups. Wald chi square followed by pairwise comparisons was used to compare CS between multiple groups. RESULTS: We included 12 patients with rod-cone dystrophy (RCD), 3 patients with Stargardt disease (STGD) and 2 patients with Best disease. Patients with IRD had significantly worse CS than controls (p < 0.001) in all spatial frequencies. Patients with STGD had more marked deficits in CS than patients with Best disease (p < 0.001) and RCD (p < 0.001) despite having similar visual acuities. CONCLUSION: Patients with IRD, especially patients with STGD with relatively preserved visual acuity have marked deficits in CS when measured across a range of spatial frequencies. We recommend that clinical trials for STGD incorporate CS measured over a range of spatial frequencies as a secondary clinical endpoint for monitoring visual function. CS may provide an explanation for complaints of visual dysfunction when visual acuity is not significantly altered.

Double hyperautofluorescent ring on fundus autofluorescence in ABCA4.

We report an unusual phenotype in a child with a clinical diagnosis of recessive Stargardt disease (STGD1) and two pathogenic variants in the ABCA4 gene. Typically, the diagnosis of early-onset STGD1 is challenging because children may present with a variety of fundus changes and a variable rate of progression. At the time of his initial visit, the 6-year-old boy presented with 20/200 OD (right eye) and 20/150 OS (left eye), symmetrical mild foveal atrophy without flecks on fundus exam, and foveal hypoautofluorescence surrounded by a homogeneous hyperautofluorescent background on wide-field fundus autofluorescence. Over 4 years of follow-up, the retinal atrophy continued to progress, resulting in two well-defined and concentric hyperautofluorescent rings: one ring located at the posterior pole and the other located around the peripapillary region. Visual acuity also deteriorated to counting fingers at 4ft OD and 20/500 OS. To the best of our knowledge, this phenotype has not been previously described with the ABCA4 gene.

Reliability of kinetic visual field testing in children with mutation-proven retinal dystrophies: Implications for therapeutic clinical trials.

PURPOSE: Kinetic visual field testing is used to monitor disease course in retinal dystrophy clinical care and treatment response in treatment trials, which are increasingly recruiting children. This study investigates Goldmann visual field (GVF) changes in young children with mutation-proven retinal dystrophies as they age and with progression of the retinal degeneration. METHODS: Retrospective review of children ≤ 17 years old with a mutation-proven retinal dystrophy. Objective clinical disease activity was assessed by a retinal degeneration specialist masked to GVF results. Digital quantification of GVF area was performed. RESULTS: Twenty-nine children (58 eyes), ages 5-16, were identified. GVF area increased with age despite progression in 20 children and clinical stability in nine children. Mean ± standard error increase in GVF area/year was 333 ± 130 mm2 (I4e, p = 0.012), 720 ± 155 mm2 (III4e, p < 0.001), and 759 ± 167 mm2 (IV4e, p < 0.001), with greater increases at earlier ages. Repeatability coefficients were 7381 mm2 (I4e), 9379 mm2 (III4e), and 10346 mm2 (IV4e), indicating a large variability. At 2.5 years after the baseline GVF the area increased ≥ 20%, the criterion for positive treatment outcome defined in recent published therapeutic trials, in 38% (I4e), 34% (III4e), and 33% (IV4e) of eyes. CONCLUSION: In a substantial proportion of children with mutation-proven retinal dystrophies, there is a significant increase in GVF area with age, particularly those < 12 years, despite progression or stability of disease. These findings suggest that change in GVF area in children with retinal dystrophies can be an unreliable measure of response to treatment and on which to base appropriate counseling about visual impairment.

Peripheral Pigmented Retinal Lesions in Stargardt Disease.

PURPOSE: To investigate the prevalence of peripheral pigmented retinal lesions and associated clinical findings in patients with Stargardt disease. DESIGN: Retrospective case series. METHODS: Records at a single academic institution were reviewed for patients with genetically confirmed Stargardt disease with peripheral pigmented retinal lesions on wide-field retinal imaging. For this cohort we described demographics, clinical features, and pathogenic variants. RESULTS: Out of 62 patients with Stargardt disease and wide-field retinal imaging, 14 had peripheral pigmented retinal lesions. These flat, subretinal lesions were located in the mid or far periphery and had well-defined borders, resembling congenital hypertrophy of retinal pigment epithelium (CHRPE) lesions. For this group of 14 patients, median age at initial diagnosis of Stargardt disease was 9.5 years, and the median duration of disease was 21.5 years. Median Snellen visual acuity was 20/200, and median central scotoma size was 20.0 degrees. All 14 patients had electroretinographic abnormalities. Four out of 14 patients developed new lesions during clinical follow-up. CONCLUSIONS: Wide-field retinal imaging revealed the presence of peripheral pigmented retinal lesions resembling CHRPE lesions in a subset of patients with genetically confirmed Stargardt disease. Presence of these lesions may be associated with severe phenotypes of the disease.

Peripheral Visual Fields in ABCA4 Stargardt Disease and Correlation With Disease Extent on Ultra-widefield Fundus Autofluorescence.

PURPOSE: To evaluate the disease extent on ultra-widefield fundus autofluorescence (UWF-FAF) in patients with ABCA4 Stargardt disease (STGD) and correlate these data with functional outcome measures. DESIGN: Retrospective cross-sectional study. METHODS: Setting: Kellogg Eye Center, University of Michigan. STUDY POPULATION: Sixty-five patients with clinical diagnosis and proven pathogenic variants in the ABCA4 gene. Observational Procedures: The UWF-FAF images were obtained using Optos (200 degrees) and classified into 3 types. Functional testing included kinetic widefield perimetry, full-field electroretinogram (ffERG), and visual acuity (VA). All results were evaluated with respect to UWF-FAF classification. MAIN OUTCOME MEASURES: Classification of UWF-FAF; area comprising the I4e, III4e, and IV4e isopters; ffERG patterns; and VA. RESULTS: For UWF-FAF, 27 subjects (41.5%) were classified as type I, 17 (26.2%) as type II, and 21 (32.4%) as type III. The area of each isopter correlated inversely with the extent of the disease and all isopters were able to detect differences among UWF-FAF types (IV4e, P = .0013; III4e, P = .0003; I4e, P < .0001 = 3.93e-8). ffERG patterns and VA were also different among the 3 UWF-FAF types (P < .001 = 6.61e-6 and P < .001 = 7.3e-5, respectively). CONCLUSION: Patients with widespread disease presented with more constriction of peripheral visual fields and had more dysfunction on ffERG and worse VA compared to patients with disease confined to the macula. UWF-FAF images may provide information for estimating peripheral and central visual function in STGD.

Modulation of Drosophila male behavioral choice.

The reproductive and defensive behaviors that are initiated in response to specific sensory cues can provide insight into how choices are made between different social behaviors. We manipulated both the activity and sex of a subset of neurons and found significant changes in male social behavior. Results from aggression assays indicate that the neuromodulator octopamine (OCT) is necessary for Drosophila males to coordinate sensory cue information presented by a second male and respond with the appropriate behavior: aggression rather than courtship. In competitive male courtship assays, males with no OCT or with low OCT levels do not adapt to changing sensory cues and court both males and females. We identified a small subset of neurons in the suboesophageal ganglion region of the adult male brain that coexpress OCT and male forms of the neural sex determination factor, Fruitless (Fru(M)). A single Fru(M)-positive OCT neuron sends extensive bilateral arborizations to the suboesophageal ganglion, the lateral accessory lobe, and possibly the posterior antennal lobe, suggesting a mechanism for integrating multiple sensory modalities. Furthermore, eliminating the expression of Fru(M) by transformer expression in OCT/tyramine neurons changes the aggression versus courtship response behavior. These results provide insight into how complex social behaviors are coordinated in the nervous system and suggest a role for neuromodulators in the functioning of male-specific circuitry relating to behavioral choice.