Patients' perspectives on prenatal screening results that suggest maternal cancer: A qualitative analysis.

OBJECTIVE: To explore patient perspectives after receiving non-invasive prenatal testing (NIPT) results that suggest maternal cancer. METHODS: Individuals who received non-reportable or discordant NIPT results during pregnancy and enrolled in a study were interviewed prior to and after receiving the outcome of their clinical evaluation for cancer. Interviews were independently coded by two researchers and analyzed thematically. RESULTS: Forty-nine participants were included. Three themes were identified: 1) limited pre-test awareness of maternal incidental findings caused considerable confusion for participants, whose initial concerns focused on their babies; 2) providers' communication influenced how participants perceived their risk of cancer and the need to be evaluated; and 3) participants perceived value in receiving maternal incidental findings from NIPT despite any stress it caused during their pregnancy. CONCLUSION: Participants viewed the ability to detect occult malignancy as an added benefit of NIPT and felt strongly that these results should be disclosed. Obstetric providers need to be aware of maternal incidental findings from NIPT, inform pregnant people of the potential to receive these results during pre-test counseling, and provide accurate and objective information during post-test counseling. CLINICAL TRIAL REGISTRATION: Incidental Detection of Maternal Neoplasia Through Non-Invasive Cell-Free DNA Analysis (IDENTIFY), a Natural History Study, NCT4049604.

Natural History of Visual Dysfunction in ABCA4 Retinopathy and Its Genetic Correlates.

PURPOSE: To systematically assess the ability to detect change and retest reliability for a panel of visual function assessments in ABCA4 retinopathy. DESIGN: Prospective natural history study (NCT01736293). METHODS: Patients with at least 1 documented pathogenic ABCA4 variant and a clinical phenotype consistent with ABCA4 retinopathy were recruited from a tertiary referral center. Participants underwent longitudinal, multifaceted functional testing, including measures of function at fixation (best-corrected visual acuity, low-vision Cambridge Color Test), macular function (microperimetry), and retina-wide function (full-field electroretinography [ERG]). Two- and 5-year ability to detect change was determined based on the η2 statistic. RESULTS: A total of 134 eyes from 67 participants with a mean follow-up of 3.65 years were included. In the 2-year interval, the microperimetry-derived perilesional sensitivity (η2 of 0.73 [0.53, 0.83]; -1.79 dB/y [-2.2, -1.37]) and mean sensitivity (η2 of 0.62 [0.38, 0.76]; -1.28 dB/y [-1.67, -0.89]) showed most change over time, but could only be recorded in 71.6% of the participants. In the 5-year interval, the dark-adapted ERG a- and b-wave amplitude showed marked change over time as well (eg, DA 30 a-wave amplitude with an η2 of 0.54 [0.34, 0.68]; -0.02 log10(µV)/y [-0.02, -0.01]). The genotype explained a large fraction of variability in the ERG-based age of disease initiation (adjusted R2 of 0.73) CONCLUSIONS: Microperimetry-based clinical outcome assessments were most sensitive to change but could only be acquired in a subset of participants. Across a 5-year interval, the ERG DA 30 a-wave amplitude was sensitive to disease progression, potentially allowing for more inclusive clinical trial designs encompassing the whole ABCA4 retinopathy spectrum.

Variants of LRP2, encoding a multifunctional cell-surface endocytic receptor, associated with hearing loss and retinal dystrophy.

Hereditary deafness and retinal dystrophy are each genetically heterogenous and clinically variable. Three small unrelated families segregating the combination of deafness and retinal dystrophy were studied by exome sequencing (ES). The proband of Family 1 was found to be compound heterozygous for NM_004525.3: LRP2: c.5005A > G, p.(Asn1669Asp) and c.149C > G, p.(Thr50Ser). In Family 2, two sisters were found to be compound heterozygous for LRP2 variants, p.(Tyr3933Cys) and an experimentally confirmed c.7715 + 3A > T consensus splice-altering variant. In Family 3, the proband is compound heterozygous for a consensus donor splice site variant LRP2: c.8452_8452 + 1del and p.(Cys3150Tyr). In mouse cochlea, Lrp2 is expressed abundantly in the stria vascularis marginal cells demonstrated by smFISH, single-cell and single-nucleus RNAseq, suggesting that a deficiency of LRP2 may compromise the endocochlear potential, which is required for hearing. LRP2 variants have been associated with Donnai-Barrow syndrome and other multisystem pleiotropic phenotypes different from the phenotypes of the four cases reported herein. Our data expand the phenotypic spectrum associated with pathogenic variants in LRP2 warranting their consideration in individuals with a combination of hereditary hearing loss and retinal dystrophy.

Investigating Determinants and Evaluating Deep Learning Training Approaches for Visual Acuity in Foveal Hypoplasia.

Purpose: To describe the relationships between foveal structure and visual function in a cohort of individuals with foveal hypoplasia (FH) and to estimate FH grade and visual acuity using a deep learning classifier. Design: Retrospective cohort study and experimental study. Participants: A total of 201 patients with FH were evaluated at the National Eye Institute from 2004 to 2018. Methods: Structural components of foveal OCT scans and corresponding clinical data were analyzed to assess their contributions to visual acuity. To automate FH scoring and visual acuity correlations, we evaluated the following 3 inputs for training a neural network predictor: (1) OCT scans, (2) OCT scans and metadata, and (3) real OCT scans and fake OCT scans created from a generative adversarial network. Main Outcome Measures: The relationships between visual acuity outcomes and determinants, such as foveal morphology, nystagmus, and refractive error. Results: The mean subject age was 24.4 years (range, 1-73 years; standard deviation = 18.25 years) at the time of OCT imaging. The mean best-corrected visual acuity (n = 398 eyes) was equivalent to a logarithm of the minimal angle of resolution (LogMAR) value of 0.75 (Snellen 20/115). Spherical equivalent refractive error (SER) ranged from -20.25 diopters (D) to +13.63 D with a median of +0.50 D. The presence of nystagmus and a high-LogMAR value showed a statistically significant relationship (P < 0.0001). The participants whose SER values were farther from plano demonstrated higher LogMAR values (n = 382 eyes). The proportion of patients with nystagmus increased with a higher FH grade. Variability in SER with grade 4 (range, -20.25 D to +13.00 D) compared with grade 1 (range, -8.88 D to +8.50 D) was statistically significant (P < 0.0001). Our neural network predictors reliably estimated the FH grading and visual acuity (correlation to true value > 0.85 and > 0.70, respectively) for a test cohort of 37 individuals (98 OCT scans). Training the predictor on real OCT scans with metadata and fake OCT scans improved the accuracy over the model trained on real OCT scans alone. Conclusions: Nystagmus and foveal anatomy impact visual outcomes in patients with FH, and computational algorithms reliably estimate FH grading and visual acuity.

Early-Onset TIMP3-Related Retinopathy Associated With Impaired Signal Peptide.

Importance: Sorsby fundus dystrophy is a typically adult-onset maculopathy with high risk for choroidal neovascularization. Sorsby fundus dystrophy, inherited as an autosomal dominant fully penetrant trait, is associated with TIMP3 variants that cause protein aggregation in the extracellular matrix. Objective: To evaluate the phenotype and underlying biochemical mechanism of disease-causing TIMP3 variants altering the N-terminal signal peptide in 2 families who have early-onset diffuse maculopathy without choroidal neovascularization with cosegregation of TIMP3 variants in the signal peptide sequence. Design, Setting, and Participants: This case series of 2 families with early-onset diffuse maculopathy was conducted at the National Eye Institute, National Institutes of Health Clinical Center. Data were collected and analyzed from October 2009 to December 2021. Main Outcomes and Measures: Clinical imaging and molecular genetic testing were performed in 2 families with macular dystrophy. Cosegregation analysis of TIMP3 variants was performed in affected and unaffected family members. Candidate TIMP3 signal peptide variants were assessed for cleavage defects after transfection. Results: Eleven individuals from 2 families with early-onset diffuse maculopathy without choroidal neovascularization harbor TIMP3 variants (L10H or G12R) in the N-terminal signaling peptide were analyzed. Cosegregation with phenotype was confirmed in additional family members. Biochemical analysis confirmed defects in both protein maturation and extracellular deposition. Conclusions and Relevance: This study found that TIMP3 variants altering signal peptide function deviated from classic Sorsby fundus dystrophy both in phenotypic features and underlying mechanism. These results suggest atypical patient presentations are caused by TIMP3 signal peptide defects, associated with impaired cleavage and deposition into the extracellular matrix, implicating a novel macular dystrophy disease.

Predominant Founder Effect among Recurrent Pathogenic Variants for an X-Linked Disorder.

For disorders with X-linked inheritance, variants may be transmitted through multiple generations of carrier females before an affected male is ascertained. Pathogenic RS1 variants exclusively cause X-linked retinoschisis (XLRS). While RS1 is constrained to variation, recurrent variants are frequently observed in unrelated probands. Here, we investigate recurrent pathogenic variants to determine the relative burden of mutational hotspot and founder allele events to this phenomenon. A cohort RS1 variant analysis and standardized classification, including variant enrichment in the XLRS cohort and in RS1 functional domains, were performed on 332 unrelated XLRS probands. A total of 108 unique RS1 variants were identified. A subset of 19 recurrently observed RS1 variants were evaluated in 190 probands by a haplotype analysis, using microsatellite and single nucleotide polymorphisms. Fourteen variants had at least two probands with common variant-specific haplotypes over ~1.95 centimorgans (cM) flanking RS1. Overall, 99/190 of reportedly unrelated probands had 25 distinct shared haplotypes. Examination of this XLRS cohort for common RS1 haplotypes indicates that the founder effect plays a significant role in this disorder, including variants in mutational hotspots. This improves the accuracy of clinical variant classification and may be generalizable to other X-linked disorders.

Photoreceptor degeneration in ABCA4-associated retinopathy and its genetic correlates.

BACKGROUNDOutcome measures sensitive to disease progression are needed for ATP-binding cassette, sub-family A, member 4-associated (ABCA4-associated) retinopathy. We aimed to quantify ellipsoid zone (EZ) loss and photoreceptor degeneration beyond EZ-loss in ABCA4-associated retinopathy and investigate associations between photoreceptor degeneration, genotype, and age.METHODSWe analyzed 132 eyes from 66 patients (of 67 enrolled) with molecularly confirmed ABCA4-associated retinopathy from a prospective natural history study with a median [IQR] follow-up of 4.2 years [3.1, 5.1]. Longitudinal spectral-domain optical coherence tomography volume scans (37 B-scans, 30° × 15°) were segmented using a deep learning (DL) approach. For genotype-phenotype analysis, a model of ABCA4 variants was applied with the age of criterion EZ-loss (6.25 mm2) as the dependent variable.RESULTSPatients exhibited an average (square-root-transformed) EZ-loss progression rate of [95% CI] 0.09 mm/y [0.06, 0.11]. Outer nuclear layer (ONL) thinning extended beyond the area of EZ-loss. The average distance from the EZ-loss boundary to normalization of ONL thickness (to ±2 z score units) was 3.20° [2.53, 3.87]. Inner segment (IS) and outer segment (OS) thinning was less pronounced, with an average distance from the EZ-loss boundary to layer thickness normalization of 1.20° [0.91, 1.48] for the IS and 0.60° [0.49, 0.72] for the OS. An additive model of allele severity explained 52.7% of variability in the age of criterion EZ-loss.CONCLUSIONPatients with ABCA4-associated retinopathy exhibited significant alterations of photoreceptors outside of EZ-loss. DL-based analysis of photoreceptor laminae may help monitor disease progression and estimate the severity of ABCA4 variants.TRIAL REGISTRATIONClinicalTrials.gov identifier: NCT01736293.FUNDINGNational Eye Institute Intramural Research Program and German Research Foundation grant PF950/1-1.

Persistent Dark Cones in Oligocone Trichromacy Revealed by Multimodal Adaptive Optics Ophthalmoscopy.

Dark cone photoreceptors, defined as those with diminished or absent reflectivity when observed with adaptive optics (AO) ophthalmoscopy, are increasingly reported in retinal disorders. However, their structural and functional impact remain unclear. Here, we report a 3-year longitudinal study on a patient with oligocone trichromacy (OT) who presented with persistent, widespread dark cones within and near the macula. Diminished electroretinogram (ERG) cone but normal ERG rod responses together with normal color vision confirmed the OT diagnosis. In addition, the patient had normal to near normal visual acuity and retinal sensitivity. Occasional dark gaps in the photoreceptor layer were observed on optical coherence tomography, in agreement with reflectance AO scanning light ophthalmoscopy, which revealed that over 50% of the cones in the fovea were dark, increasing to 74% at 10° eccentricity. In addition, the cone density was 78% lower than normal histologic value at the fovea, and 20-40% lower at eccentricities of 5-15°. Interestingly, color vision testing was near normal at locations where cones were predominantly dark. These findings illustrate how a retina with predominant dark cones that persist over at least 3 years can support near normal central retinal function. Furthermore, this study adds to the growing evidence that cones can continue to survive under non-ideal conditions.

Vestibular phenotype-genotype correlation in a cohort of 90 patients with Usher syndrome.

Usher syndrome has been historically categorized into one of three classical types based on the patient phenotype. However, the vestibular phenotype does not infallibly predict which Usher genes are mutated. Conversely, the Usher syndrome genotype is not sufficient to reliably predict vestibular function. Here we present a characterization of the vestibular phenotype of 90 patients with clinical presentation of Usher syndrome (59 females), aged 10.9 to 75.5 years, with genetic variants in eight Usher syndromic genes and expand the description of atypical Usher syndrome. We identified unexpected horizontal semicircular canal reactivity in response to caloric and rotational stimuli in 12.5% (3 of 24) and 41.7% (10 of 24), respectively, of our USH1 cohort. These findings are not consistent with the classical phenotypic definition of vestibular areflexia in USH1. Similarly, 17% (6 of 35) of our cohort with USH2A mutations had saccular dysfunction as evidenced by absent cervical vestibular evoked myogenic potentials in contradiction to the classical assumption of normal vestibular function. The surprising lack of consistent genotypic to vestibular phenotypic findings as well as no clear vestibular phenotypic patterns among atypical USH cases, indicate that even rigorous vestibular phenotyping data will not reliably differentiate the three USH types.

Clinical Features of Optic Disc Drusen in an Ophthalmic Genetics Cohort.

MATERIALS AND METHODS: Electronic medical records of patients evaluated in the Ophthalmic Genetics clinic at the National Eye Institute (NEI) between 2008 and 2018 were searched for a superficial ODD diagnosis. Color fundus and autofluorescence images were reviewed to confirm ODD, supplemented with optical coherence tomography (OCT) in uncertain cases when available. Demographic information, examination, and genetic testing were reviewed. Disc areas and disc-to-macula distance to disc diameter ratios (DM : DD) were calculated. RESULTS: Fifty six of 6207 patients had photographically confirmed ODD (0.9%). Drusen were predominantly bilateral (66%), with a female (62%) and Caucasian (73%) predilection. ODD prevalence in our cohort of patients with inherited retinal degenerations was 2.5%, and ODD were more prevalent in the rod-cone dystrophy subgroup at 2.95% (OR = 3.3 [2.1-5.3], P < 0.001) compared to the ophthalmic genetics cohort. Usher patients were more likely to have ODD (10/132, 7.6%, OR = 9.0 [4.3-17.7], P < 0.001) and had significantly smaller discs compared to the rest of our ODD cohort (disc area: P=0.001, DM : DD: P=0.03). Discussion. While an association between ODD and retinitis pigmentosa has been reported, this study surveys a large cohort of patients with inherited eye conditions and finds the prevalence of superficial ODD is lower than that in the literature. Some subpopulations, such as rod-cone dystrophy and Usher syndrome, had a higher prevalence than the cohort as a whole.

Atypical and ultra-rare Usher syndrome: a review.

Usher syndrome has classically been described as a combination of hearing loss and rod-cone dystrophy; vestibular dysfunction is present in many patients. Three distinct clinical subtypes were documented in the late 1970s. Genotyping efforts have led to the identification of several genes associated with the disease. Recent literature has seen multiple publications referring to "atypical" Usher syndrome presentations. This manuscript reviews the molecular etiology of Usher syndrome, highlighting rare presentations and molecular causes. Reports of "atypical" disease are summarized noting the wide discrepancy in the spectrum of phenotypic deviations from the classical presentation. Guidelines for establishing a clear nomenclature system are suggested.

Expanding the genotypic spectrum of Jalili syndrome: Novel CNNM4 variants and uniparental isodisomy in a north American patient cohort.

Jalili syndrome is a rare multisystem disorder with the most prominent features consisting of cone-rod dystrophy and amelogenesis imperfecta. Few cases have been reported in the Americas. Here we describe a case series of patients with Jalili syndrome examined at the National Eye Institute's Ophthalmic Genetics clinic between 2016 and 2018. Three unrelated sporadic cases were systematically evaluated for ocular phenotype and determined to have cone-rod dystrophy with bull's eye maculopathy, photophobia, and nystagmus. All patients had amelogenesis imperfecta. Two of these patients had Guatemalan ancestry and the same novel homozygous CNNM4 variant (p.Arg236Trp c.706C > T) without evidence of consanguinity. This variant met likely pathogenic criteria by the American College of Medical Genetics guidelines. An additional patient had a homozygous deleterious variant in CNNM4 (c.279delC p.Phe93Leufs*31), which resulted from paternal uniparental isodisomy for chromosome 2p22-2q37. This individual had additional syndromic features including developmental delay and spastic diplegia, likely related to mutations at other loci. Our work highlights the genotypic variability of Jalili syndrome and expands the genotypic spectrum of this condition by describing the first series of patients seen in the United States.

Psychosocial impacts of Mendelian eye conditions: A systematic literature review.

The diagnosis of a heritable (Mendelian) eye condition can have a significant impact on patients and their families. Although a diverse group of conditions, many Mendelian eye conditions are early-onset, untreatable, progressive, and result in significant visual disability. To increase understanding of the challenges faced by this population, we review studies describing the psychosocial impacts of Mendelian eye conditions. Reduced mental health and quality of life and increased strain on relationships are common themes. We synthesize the evidence presented in this review to propose an overall model of illness factors, cultural factors, psychosocial impacts, and quality of life. Finally, we discuss implications for patient management and future research directions.

"There Are Hills and Valleys": Experiences of Parenting a Son With X-Linked Retinoschisis.

PURPOSE: To explore the experiences of parents of sons with X-linked retinoschisis (XLRS). DESIGN: Mixed methods-qualitative interviews with quantitative survey. METHODS: Parents of sons with XLRS who were evaluated at the National Eye Institute between December 2017 and January 2019 were eligible for this study. Participation involved engaging in a semistructured interview and completing a survey assessing optimism, anxiety, personality traits, and sociodemographics using valid and reliable scales. Interview transcripts were coded and analyzed thematically, and scales were scored and used descriptively. RESULTS: Eleven mothers and 8 fathers from 13 families participated. Optimism, anxiety, and personality traits fell into the normative ranges for the scales. Parents described a process of continuous adaptation to their son's condition. The initial diagnosis was characterized by shock, grief, and "devastation" for most parents. Maternal guilt was common, but usually lessened over time. As parents adjusted to life postdiagnosis, they attempted to achieve a state of normalcy while balancing a desire to protect their sons. Significant sources of stress included decisions around sports participation and driving. Among all parents, the fear of retinal detachment was an ongoing concern. Most parents did identify perceived benefits from their experiences, such as feelings of gratitude or family cohesion. CONCLUSIONS: Most parents viewed XLRS as a significant challenge in their sons' lives, but one that could be overcome. Clinical encounters may be enhanced for families with XLRS by providing accurate information, preparing families for potential challenges, anticipating stressful decisions, and meeting other families with XLRS.

Motivations and Decision Making Processes of Men With X-linked Retinoschisis Considering Participation in an Ocular Gene Therapy Trial.

PURPOSE: To describe the motivations, expectations, and other factors men with X-linked retinoschisis (XLRS) consider when making decisions to participate in an early phase ocular gene therapy clinical trial. DESIGN: Qualitative interview study. METHODS: Men with XLRS who were considering participation in a phase I/IIa ocular gene therapy clinical trial at the National Eye Institute were eligible for this study. Trial participants (n = 9) were interviewed prior to receiving the gene transfer and then at 3 and 12 months later. Trial participation decliners (n = 2) were interviewed at an initial visit and 12 months later. Those screened for the trial and found ineligible (n = 2) were interviewed at an initial visit only. Interviews were transcribed, coded, and analyzed thematically. RESULTS: Interview participants described decision making factors as risk-benefit assessments, personal intuition, trust in the study team, and religious faith. Altruism and the potential for therapeutic benefit were the main motives for trial participation, whereas the uncertainty of risks and benefits was the reason 2 men declined participation. Although most participants hoped for direct benefit, no one expected to benefit. Almost all interview participants considered their decision straightforward and were satisfied with their decision when interviewed over time. Meaningful relationships with the study team and perceived secondary benefits to participation contributed to positive trial experiences. CONCLUSIONS: Engaging prospective research participants in a discussion about their hopes, expectations, and personal factors provides a more complete understanding of patient decision making and may help support informed choices to participate in clinical trials for XLRS.

Considerations in multi-gene panel testing in pediatric ophthalmology.

Multi-gene panel testing is used increasingly in ophthalmology practice as an efficient and cost-effective method for diagnosing inherited eye conditions. Panel testing is a powerful diagnostic tool, and it has the potential to reveal syndromic information in patients with seemingly isolated eye findings. This case series highlights our experience with 4 children in 3 families who were referred for evaluation of an isolated retinal degeneration and diagnosed with neuronal ceroid lipofuscinosis on panel testing. These cases are important reminders that several neurodegenerative conditions can present initially with isolated eye findings in childhood and pretest genetic counseling is critical.

DICER1 Syndrome: Characterization of the Ocular Phenotype in a Family-Based Cohort Study.

PURPOSE: To characterize the ocular phenotype of DICER1 syndrome. DESIGN: Prospective, single-center, case-control study. PARTICIPANTS: One hundred three patients with an identified germline pathogenic DICER1 variant (DICER1 carriers) and 69 family control participants underwent clinical and ophthalmic examination at the National Institutes of Health between 2011 and 2016. METHODS: All participants were evaluated with a comprehensive ophthalmic examination, including best-corrected visual acuity, slit-lamp biomicroscopy, and a dilated fundus examination. A subset of patients returned for a more detailed evaluation including spectral-domain OCT, color fundus photography, fundus autofluorescence imaging, visual field testing, full-field electroretinography, and genetic testing for inherited retinal degenerative diseases. MAIN OUTCOME MEASURES: Visual acuity and examination findings. RESULTS: Most DICER1 carriers (97%) maintained a visual acuity of 20/40 or better in both eyes. Twenty-three DICER1 carriers (22%) showed ocular abnormalities compared with 4 family controls (6%; P = 0.005). These abnormalities included retinal pigment abnormalities (n = 6 [5.8%]), increased cup-to-disc ratio (n = 5 [4.9%]), optic nerve abnormalities (n = 2 [1.9%]), epiretinal membrane (n = 2 [1.9%]), and drusen (n = 2 [1.9%]). Overall, we observed a significant difference (P = 0.03) in the rate of retinal abnormalities in DICER1 carriers (n = 11 [11%]) versus controls (n = 1 [1.5%]). One patient demonstrated an unexpected diagnosis of retinitis pigmentosa with a novel variant of unknown significance in PRPF31, and 1 showed optic nerve elevation in the setting of increased intracranial pressure (ICP) of unclear cause. Three patients (3%) demonstrated DICER1-related ciliary body medulloepithelioma (CBME), 2 of which were identified during routine examination, a higher rate than that reported previously. CONCLUSIONS: Ophthalmologists should be aware of the ophthalmic manifestations of DICER1 syndrome, and individuals and families should be counseled on the potential signs and symptoms. We recommend that children with a germline pathogenic variant in DICER1, especially those younger than 10 years, undergo annual dilated ophthalmic examination, looking for evidence of CBME, signs of increased ICP, and perhaps changes in the retinal pigment epithelium.

Retinal AAV8-RS1 Gene Therapy for X-Linked Retinoschisis: Initial Findings from a Phase I/IIa Trial by Intravitreal Delivery.

This study evaluated the safety and tolerability of ocular RS1 adeno-associated virus (AAV8-RS1) gene augmentation therapy to the retina of participants with X-linked retinoschisis (XLRS). XLRS is a monogenic trait affecting only males, caused by mutations in the RS1 gene. Retinoschisin protein is secreted principally in the outer retina, and its absence results in retinal cavities, synaptic dysfunction, reduced visual acuity, and susceptibility to retinal detachment. This phase I/IIa single-center, prospective, open-label, three-dose-escalation clinical trial administered vector to nine participants with pathogenic RS1 mutations. The eye of each participant with worse acuity (≤63 letters; Snellen 20/63) received the AAV8-RS1 gene vector by intravitreal injection. Three participants were assigned to each of three dosage groups: 1e9 vector genomes (vg)/eye, 1e10 vg/eye, and 1e11 vg/eye. The investigational product was generally well tolerated in all but one individual. Ocular events included dose-related inflammation that resolved with topical and oral corticosteroids. Systemic antibodies against AAV8 increased in a dose-related fashion, but no antibodies against RS1 were observed. Retinal cavities closed transiently in one participant. Additional doses and immunosuppressive regimens are being explored to pursue evidence of safety and efficacy (ClinicalTrials.gov: NCT02317887).