Deep Learning of the Retina Enables Phenome- and Genome-Wide Analyses of the Microvasculature.

BACKGROUND: The microvasculature, the smallest blood vessels in the body, has key roles in maintenance of organ health and tumorigenesis. The retinal fundus is a window for human in vivo noninvasive assessment of the microvasculature. Large-scale complementary machine learning-based assessment of the retinal vasculature with phenome-wide and genome-wide analyses may yield new insights into human health and disease. METHODS: We used 97 895 retinal fundus images from 54 813 UK Biobank participants. Using convolutional neural networks to segment the retinal microvasculature, we calculated vascular density and fractal dimension as a measure of vascular branching complexity. We associated these indices with 1866 incident International Classification of Diseases-based conditions (median 10-year follow-up) and 88 quantitative traits, adjusting for age, sex, smoking status, and ethnicity. RESULTS: Low retinal vascular fractal dimension and density were significantly associated with higher risks for incident mortality, hypertension, congestive heart failure, renal failure, type 2 diabetes, sleep apnea, anemia, and multiple ocular conditions, as well as corresponding quantitative traits. Genome-wide association of vascular fractal dimension and density identified 7 and 13 novel loci, respectively, that were enriched for pathways linked to angiogenesis (eg, vascular endothelial growth factor, platelet-derived growth factor receptor, angiopoietin, and WNT signaling pathways) and inflammation (eg, interleukin, cytokine signaling). CONCLUSIONS: Our results indicate that the retinal vasculature may serve as a biomarker for future cardiometabolic and ocular disease and provide insights into genes and biological pathways influencing microvascular indices. Moreover, such a framework highlights how deep learning of images can quantify an interpretable phenotype for integration with electronic health record, biomarker, and genetic data to inform risk prediction and risk modification.

The influence of the topographic location of geographic atrophy on vision-related quality of life in nonexudative age-related macular degeneration.

PURPOSE: To examine associations between the topographic distribution of geographic atrophy (GA) and vision-related quality of life (VRQoL). METHODS: This study included 237 eyes from 161 participants in the Age-Related Eye Disease Study (AREDS). GA lesions were manually delineated with color fundus photographs obtained by the AREDS Research Group and atrophic area was measured in an Early Treatment Diabetic Retinopathy Study (ETDRS) grid. VRQoL was measured using the National Eye Institute Visual Function Questionnaire (NEI-VFQ). Area of atrophy in the ETDRS grid subfields was correlated with VRQoL by linear regression modeling. RESULTS: The average area of atrophy in the better and worse eye was 3.43mm2 and 7.15mm2 respectively. In multivariable analysis, VRQoL was not associated with total area of atrophy in the better eye (ß, - 0.53; 95% confidence interval [CI], - 1.11 to 0.05; P = 0.07) or worse eye (ß, 0.12; 95% CI, - 0.32 to 0.55; P = 0.59). However, area of atrophy in the central 1-mm-diameter zone of the better eye was significantly associated with VRQoL when the ETDRS subfields were examined individually (ß, - 14.57; 95% CI, - 27.12 to - 2.02; P = 0.023), grouped into quadrants (ß, - 18.35; 95% CI, - 30.03 to - 6.67; P = 0.002), inner and outer zones (ß, - 17.26; 95% CI, - 29.38 to - 5.14; P = 0.006), or vertical and horizontal zones (ß, - 18.97; 95% CI, - 30.18 to - 7.77; P = 0.001). CONCLUSION: In patients with GA, greater area of atrophy in the central 1-mm-diameter zone of the better eye was independently associated with lower VRQoL, while total area of atrophy in the better or worse eye was not.

Association of the Affordable Care Act with Eye-Related Emergency Department Utilization in the United States.

PURPOSE: To investigate the association of the Affordable Care Act (ACA) with nationwide eye-related emergency department (ED) use. DESIGN: Retrospective, cross-sectional study. PARTICIPANTS: All patients who presented to the ED with an eye-related primary diagnosis were eligible for inclusion. METHODS: Nationally representative data from the US Nationwide Emergency Department Sample were used to analyze eye-related ED visits before (2010-2013) and after (2014-2017) the ACA was mandated. All ED visits were categorized as emergent or nonemergent or could not be determined. MAIN OUTCOME MEASURES: The primary outcome was to compare the nationwide and regional incidence of eye-related ED visits per 100 000 US population before (2010-2013) and after (2014-2017) the ACA was mandated. Secondary outcome measures included change in payor status, proportion of urgent versus nonurgent visits, proportion of visits at teaching versus nonteaching hospitals, associated charges, and discharge disposition. RESULTS: A total of 16 808 343 eye-related ED visits occurred in the United States during the study period from 2010 to 2017. Of these, 8 088 203 ED visits occurred before the ACA was mandated (2010-2013), and 8 720 766 ED visits occurred after the ACA was mandated (2014-2017). After the ACA was mandated in 2014, there was an initial decline in incidence of eye-related ED visits from 652.4 per 100 000 population in 2013 to 593.0 per 100 000 population in 2014, followed by a rapid increase in incidence to 658.5 per 100 000 population in 2015, with a further increase to 746.6 per 100 000 population in 2016. The percentage of uninsured patients decreased from 19.0% to 14.3%. The increase in ED use was greatest for individuals in the lowest income quartile (895.1 per 100 000 population in 2013 to 964.0 per 100 000 in 2017). Overall, 44.8% of ED visits were due to nonemergent eye conditions. CONCLUSIONS: Although the ACA increased insurance coverage for Americans, theoretically increasing access to outpatient ophthalmic care, this did not decrease ED reliance for management of ophthalmic conditions. Additional measures beyond expanding insurance coverage may be necessary to provide high-quality, efficient, and equitable outpatient ophthalmic care to all Americans.

Photoreceptor Layer Thinning Is an Early Biomarker for Age-Related Macular Degeneration: Epidemiologic and Genetic Evidence from UK Biobank OCT Data.

PURPOSE: Despite widespread use of OCT, an early-stage imaging biomarker for age-related macular degeneration (AMD) has not been identified. Pathophysiologically, the timing of drusen accumulation in relationship to photoreceptor degeneration in AMD remains unclear, as are the inherited genetic variants contributing to these processes. Herein, we jointly analyzed OCT, electronic health record data, and genomic data to characterize the time sequence of changes in retinal layer thicknesses in AMD, as well as epidemiologic and genetic associations between retinal layer thicknesses and AMD. DESIGN: Cohort study. PARTICIPANTS: Forty-four thousand eight hundred twenty-three individuals from the UK Biobank (enrollment age range, 40-70 years; 54% women; median follow-up, 10 years). METHODS: The Topcon Advanced Boundary Segmentation algorithm was used for retinal layer segmentation. We associated 9 retinal layer thicknesses with prevalent AMD (present at enrollment) in a logistic regression model and with incident AMD (diagnosed after enrollment) in a Cox proportional hazards model. Next, we associated AMD-associated genetic alleles, individually and as a polygenic risk score (PRS), with retinal layer thicknesses. All analyses were adjusted for age, age-squared (age2), sex, smoking status, and principal components of ancestry. MAIN OUTCOME MEASURES: Prevalent and incident AMD. RESULTS: Photoreceptor segment (PS) thinning was observed throughout the lifespan of individuals analyzed, whereas retinal pigment epithelium (RPE) and Bruch's membrane (BM) complex thickening started after 57 years of age. Each standard deviation (SD) of PS thinning and RPE-BM complex thickening was associated with incident AMD (PS: hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.23-1.47; P = 3.7 × 10-11; RPE-BM complex: HR, 1.14; 95% CI, 1.06-1.22; P = 0.00024). The AMD PRS was associated with PS thinning (ß, -0.21 SD per twofold genetically increased risk of AMD; 95% CI, -0.23 to -0.19; P = 2.8 × 10-74), and its association with RPE-BM complex was U-shaped (thinning with AMD PRS less than the 92nd percentile and thickening with AMD PRS more than the 92nd percentile). The loci with strongest support for genetic correlation were AMD risk-raising variants Complement Factor H (CFH):rs570618-T, CFH:rs10922109-C, and Age-Related Maculopathy Susceptibility 2 (ARMS2)/High-Temperature Requirement Serine Protease 1 (HTRA1):rs3750846-C on PS thinning and SYN3/Tissue Inhibitor of Metalloprotease 3 (TIMP3):rs5754227-T on RPE-BM complex thickening. CONCLUSIONS: Epidemiologically, PS thinning precedes RPE-BM complex thickening by decades and is the retinal layer most strongly predictive of future AMD risk. Genetically, AMD risk variants are associated with decreased PS thickness. Overall, these findings support PS thinning as an early-stage biomarker for future AMD development.

Altered transcriptome and disease-related phenotype emerge only after fibroblasts harvested from patients with age-related macular degeneration are differentiated into retinal pigment epithelium.

We have reported previously that retinal pigment epithelium (RPE) differentiated from induced pluripotent stem cells (iPSC) generated from fibroblasts of patients with age-related macular degeneration (AMD) exhibit a retinal degenerative disease phenotype and a distinct transcriptome compared to age-matched controls. Since the genetic composition of the iPSC and RPE are inherited from fibroblasts, we investigated whether differential behavior was present in the parental fibroblasts and iPSC prior to differentiation of the cell lines into RPE. Principal component analyses revealed significant overlap (essentially no differences) in the transcriptome of fibroblasts between AMD and controls. After reprogramming, there was no significant difference in the transcriptome of iPSC generated from AMD versus normal donors. In contrast, the transcriptome of RPE derived from iPSC segregated into two distinct clusters of AMD-derived cells versus controls. Interestingly, mitochondrial dysfunction in AMD-derived RPE was evident after approximately two months in culture. Moreover, these differences in mitochondrial dysfunction were not evident in the parental fibroblasts and iPSC. This study demonstrates an altered transcriptome and impaired mitochondrial function in RPE derived from AMD patients versus controls, and demonstrates these differences are not present in the original fibroblasts or iPSC. These results suggest that pathology in AMD is triggered upon differentiation of parent cells into RPE. More study of this phenomenon could advance the current understandings of the etiology of AMD and the development of novel therapeutic targets.

Central geographic atrophy vs. neovascular age-related macular degeneration: differences in longitudinal vision-related quality of life.

OBJECTIVE: Prior studies of vision-related quality of life (VRQoL) have examined advanced age-related macular degeneration (AMD) as a single group or focused on neovascular AMD (nAMD), even though advanced AMD can refer to either central geographic atrophy (GA) or nAMD. We compared the natural progression of VRQoL in central GA versus nAMD. METHODS: We included Age-Related Eye Disease Study (AREDS) participants with central GA (n = 206) or nAMD (n = 198) who completed the National Eye Institute Visual Function Questionnaire (NEI-VFQ) between 1997 and 2005. The rate of change of VRQoL was calculated as the slopes of linear models fit to longitudinal individual-level NEI-VFQ scores. Multivariable regressions identified factors associated with experiencing a decline in VRQoL during the study period and cross-sectional VRQoL score. RESULTS: There was a minor decline in VRQoL prior to the development of nAMD but a significantly steeper decline after progression to nAMD (0.49 ± 2.91 vs. 3.30 ± 5.58 NEI-VFQ units/year; p < 0.001). The rates of VRQoL decline were similar before and after the development of central GA (1.99 ± 4.97 vs. 1.68 ± 4.65 NEI-VFQ units/year; p = 0.66). Prior to the development of advanced AMD, the rate of VRQoL decline was greater for participants destined to develop central GA versus nAMD (p = 0.007), while postprogression to advanced disease, the rate was greater in nAMD compared with central GA (p = 0.012). Female gender (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.38-5.06; p = 0.003) and higher baseline VRQoL score (OR 1.03, 95% CI 1.01-1.06; p = 0.006) were independently associated with experiencing a longitudinal decline in VRQoL. CONCLUSION: The natural progression of VRQoL differed in central GA versus nAMD, both before and after the development of advanced disease, suggesting that future studies should consider separating these phenotypes. Females and those with a higher baseline VRQoL were more likely to experience a longitudinal decline in VRQoL following progression to advanced AMD.

Geographic atrophy severity and mortality in age-related macular degeneration.

PURPOSE: To examine the association between geographic atrophy (GA) disease characteristics and mortality risk. METHODS: We manually delineated color fundus photographs of 209 Age-Related Eye Disease Study (AREDS) participants with GA secondary to age-related macular degeneration to identify total area of atrophy, GA effective radius growth rate, disease laterality, and the presence of foveal center involvement. Associations between GA characteristics and mortality were assessed with Cox proportional hazards models adjusted for health status indicators. RESULTS: During a median follow-up of 6.8 years, 48 (23.0%) participants with GA died. In adjusted models, accounting for age, sex, and health status, participants with total GA area in the highest quartile had a significantly increased risk of all-cause mortality compared to those with total GA area in the lowest quartile (hazard ratio [HR], 3.42; 95% confidence interval [CI], 1.32-8.86; P = 0.011). GA effective radius growth rate, bilateral disease, and the presence of foveal center involvement were not significantly associated with mortality. In a multivariable model, including health status indicators and all GA characteristics, total area of atrophy in the highest quartile remained significantly associated with mortality (HR, 4.65; 95% CI, 1.29-16.70; P = 0.019). CONCLUSIONS: More extensive GA, as indicated by a greater total area of atrophy, was associated with an increased risk of all-cause mortality in our cohort. The extent of GA may reflect the extent of underlying disease processes that contribute to greater mortality risk, further suggesting that GA may be part of a systemic rather than purely ocular disease process.

Association of the Affordable Care Act Medicaid Expansion with Dilated Eye Examinations among the United States Population with Diabetes.

PURPOSE: To evaluate the association between Medicaid expansion and diabetic dilated eye examinations. DESIGN: A retrospective difference in differences (DiD) analysis using individual-level survey response data from January 1, 2009, to December 31, 2017. PARTICIPANTS: A total of 52 392 survey responses from 50 states and the District of Columbia between 2009 and 2017. Responders were adults aged 18 to 64 years reporting a previous diagnosis of diabetes and a household income below 138% of the US federal poverty line (FPL). METHODS: The Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System data were used to identify survey responders who were asked about the presence of dilated eye examinations from years before and after Medicaid expansion implementation. MAIN OUTCOME MEASURES: The DiD in proportion of dilated eye examinations among diabetic persons aged 18 to 64 years with household incomes below 138% of the FPL between states that did and did not implement Medicaid expansion. RESULTS: Implementation of Medicaid expansion policies was associated with a 1.3% (95% confidence interval [CI], -3.8 to 6.4; P = 0.61), 6.3% (95% CI, 1.3-11.3; P = 0.016), 4.1% (95% CI, -0.8 to 9.0; P = 0.11), and 2.3% (95% CI, -1.6 to 6.2; P = 0.23) increase in the proportion of diabetic persons aged 18 to 64 years with incomes below 138% of the FPL receiving a dilated eye examination within the past year due to Medicaid expansion 1, 2, 3, and 4 cumulative years after expansion, respectively. CONCLUSIONS: Medicaid expansion policies were significantly associated with an increase in dilated eye examination rates within the first 2 years after implementation. However, this increase did not persist beyond this period, with nonsignificant increases 3 and 4 cumulative years after implementation. Healthcare policymakers should be aware that additional measures beyond expanding insurance coverage may be necessary to increase and sustain the rate of dilated eye examinations among diabetic populations.

Natural History of Autosomal Recessive Stargardt Disease in Untreated Eyes: A Systematic Review and Meta-analysis of Study- and Individual-Level Data.

TOPIC: Systematic review and meta-analysis of the natural history of autosomal recessive Stargardt disease (STGD1). CLINICAL RELEVANCE: Controversy exists regarding the progression pattern of atrophic lesions secondary to STGD1, and the reported growth rates vary widely among studies. METHODS: We searched in 6 literature databases up through March 15, 2019, to identify studies that monitored atrophy progression by fundus autofluorescence in untreated eyes with STGD1 for 6 months or more. We analyzed both study- and individual-level data from the included studies using 3 models: the area linear model (ALM), radius linear model (RLM), and area exponential model (AEM), in which the area, radius, and natural log-transformed area changes linearly with time, respectively. A horizontal translation factor was added to each dataset to correct for different participants' entry times into the studies. The best model was determined by the predicted age of lesion onset and dependence of growth rates on baseline lesion sizes. The risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: Of 3158 articles screened, 7 studies (564 eyes) met our inclusion criteria. Cumulative study- and individual-level datasets fit along a straight line in the RLM after introducing horizontal translation factors to correct for different entry times (r2 = 0.99 and r2 = 0.93, respectively). The growth rate of effective lesion radius was 0.104 mm/year (95% confidence interval, 0.086-0.123 mm/year). The age of atrophy onset predicted by the RLM (22.7±5.0 years) was comparable to the reported age at onset of symptoms (22.1±3.1 years); in contrast, the predictions by the ALM and AEM deviated from this number by more than 5 years. Based on the individual-level data, the effective radius growth rate was independent of the baseline lesion size (r = 0.06); in comparison, the growth rates of area and natural log-transformed area were significantly dependent on the baseline lesion size (r = 0.47 and r = -0.33, respectively). CONCLUSIONS: The progression of STGD1 lesions followed the RLM in both study- and individual-level data. The effective radius growth rate of atrophic lesions could serve as a reliable outcome measure to monitor STGD1 progression.

High-throughput screening identifies compounds that protect RPE cells from physiological stressors present in AMD.

Dysfunction and eventual loss of retinal pigment epithelial (RPE) cells is a hallmark of atrophic age-related macular degeneration (AMD), and linked to oxidative and nitrosative damage. Herein, we use a high-throughput screen (HTS) to identify compounds that protect human RPE cells from oxidative stress-induced cell death and elucidate the possible mechanism of action. HTS was used to identify compounds that protect RPE cells from oxidative damage. We tested the identified compound(s) in models of RPE stress, including tert-butyl hydroperoxide (TBHP) exposure, ultraviolet-B (UV-B)-mediated light damage and nitrosative stress to the basement membrane using ARPE-19 cells, primary human RPE cells and induced-pluripotent stem cell (iPSC)-derived RPE cells from patients with AMD. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect gene expression of oxidative stress- and apoptosis-related genes and mitochondrial function was measured using a Seahorse XF96 analyzer to elucidate possible mechanisms of action. Five thousand and sixty-five compounds were screened, and of these, 12 compounds were active based on their ability to improve cell viability after exposure to TBHP. After chemical structure review, we identified ciclopirox olamine as a potent inhibitor of oxidative damage to RPE cells. Ciclopirox olamine increased cell viability in ARPE-19 cells treated with TBHP, UV-B light or on nitrite-modified extracellular matrix (ECM) by 1.68-fold, 1.54-fold and 4.3-fold, respectively (p < 0.01). Treatment with TBHP altered expression of genes related to oxidative stress and apoptosis, which was reversed by pretreatment with ciclopirox olamine. Ciclopirox olamine improved mitochondrial function in TBHP-exposed ARPE-19 cells and iPSC-derived RPE cells. Ciclopirox olamine protected primary human RPE cells and iPSC-derived RPE cells from the oxidative stress or damaged basement membrane. HTS of bioactive Food and Drug Administration (FDA)-approved libraries and follow-up studies can be used to identify small molecules (including ciclopirox olamine) that protect RPE cells exposed to various stressors associated with disease progression of AMD. This strategy can be used to identify potential compounds for treatment and prevention of AMD.

RECLASSIFICATION OF FUNDUS AUTOFLUORESCENCE PATTERNS SURROUNDING GEOGRAPHIC ATROPHY BASED ON PROGRESSION RATE: A Systematic Review and Meta-Analysis.

PURPOSE: To reclassify fundus autofluorescence (FAF) patterns around geographic atrophy (GA) based on GA progression rates. METHODS: MEDLINE, EMBASE, Cochrane Library, Clinicaltrials.gov, and PubMed were searched for studies reporting GA progression rates among different FAF patterns, such as "None," "Focal," "Banded," "Patchy," "Diffuse Nontrickling," and "Diffuse Trickling." The GA radius growth rate among different FAF patterns was compared, and a GA growth function for each group was derived. To account for the patients' different entry times, a horizontal translation factor was introduced to shift each data subset from "time after enrollment" to "duration of GA." RESULTS: Seven studies with 496 eyes were included. Based on GA radius growth rates, the six FAF patterns were clustered into four groups with a high correlation coefficient within each group: Group 1, None, 0.061 mm/year (r = 0.996), Group 2, Focal, 0.105 mm/year (r = 0.987), Group 3, Banded, Patchy, and Diffuse Nontrickling, 0.149 mm/year (r = 0.993), and Group 4, "Diffuse Trickling, 0.245 mm/year (r = 0.997). CONCLUSION: This meta-analysis suggested that the six FAF patterns can be coalesced into four groups based on lesion progression rates. Simplification of the reclassified FAF patterns may shed light on the GA natural history and assist in the design of clinical trials.

Incremental Revisions across the Life Span of Ophthalmic Devices after Initial Food and Drug Administration Premarket Approval, 1979-2015.

PURPOSE: To characterize the frequency, nature, and regulatory mechanisms by which ophthalmic devices are iteratively modified after initial Food and Drug Administration (FDA) Premarket Approval (PMA). DESIGN: Retrospective cross-sectional analysis using publicly available FDA data. PARTICIPANTS: Ophthalmic devices initially approved via the FDA's PMA pathway between January 1, 1979 and December 31, 2015. METHODS: We used the FDA's PMA Database to identify and characterize initial approvals and subsequent postmarket modifications to Class III ophthalmic devices. The FDA Recalls Database was used to identify associated safety events. MAIN OUTCOME MEASURES: Median iterated life span (timespan across which modifications occurred after initial PMA) and median number of supplements approved per device, by device type, and overall, stratified by regulatory pathway and modification type. RESULTS: Between 1979 and 2015, the FDA approved 168 original ophthalmic devices via the PMA pathway and 2813 subsequent modifications. More than one third (n = 64; 38%) of original approvals were intraocular lenses. Overall, devices underwent a median of 11 postmarket modifications (interquartile range [IQR], 3-24.8) across a median 10.0-year iterated life span (IQR, 4.1-16.7). The majority of devices (n = 144; 86%) underwent more than 1 postapproval modification, including more than 1 design modification (n = 84; 50%). The median number of changes altering device design or labeling was 3.5 (IQR, 1-9). Although manufacturing alterations (n = 834 of 2813; 30%) were the most frequent type of revision, changes involving device design (n = 667; 24%) and labeling (n = 417; 15%) were common. Recalled devices underwent more frequent postapproval modifications per year (median, 1.4; IQR, 0.7-2.3; mean, 1.5; 95% confidence interval, 1.1-1.9) in the period preceding recall than did nonrecalled devices (median, 0.5; IQR, 0.2-1.1; mean, 0.8; 95% confidence interval, 0.7-1.0) across their market approval period (P < 0.001). CONCLUSIONS: Most ophthalmic devices approved via the FDA's PMA pathway have undergone extensive revisions, including serial design and labeling changes, since their initial approvals, often without supporting clinical data. Ophthalmologists should take into consideration that cumulative revisions may render the clinical evidence that supported an original FDA approval less relevant to newer device models.

Potential of Gene Editing and Induced Pluripotent Stem Cells (iPSCs) in Treatment of Retinal Diseases.

The advent of gene editing has introduced the ability to make changes to the genome of cells, thus allowing for correction of genetic mutations in patients with monogenic diseases. Retinal diseases are particularly suitable for the application of this new technology because many retinal diseases, such as Stargardt disease, retinitis pigmentosa (RP), and Leber congenital amaurosis (LCA), are monogenic. Moreover, gene delivery techniques such as the use of adeno-associated virus (AAV) vectors have been optimized for intraocular use, and phase III trials are well underway to treat LCA, a severe form of inherited retinal degeneration, with gene therapy. This review focuses on the use of gene editing techniques and another relatively recent advent, induced pluripotent stem cells (iPSCs), and their potential for the study and treatment of retinal disease. Investment in these technologies, including overcoming challenges such as off-target mutations and low transplanted cell integration, may allow for future treatment of many debilitating inherited retinal diseases.

Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt's macular dystrophy: follow-up of two open-label phase 1/2 studies.

BACKGROUND: Since they were first derived more than three decades ago, embryonic stem cells have been proposed as a source of replacement cells in regenerative medicine, but their plasticity and unlimited capacity for self-renewal raises concerns about their safety, including tumour formation ability, potential immune rejection, and the risk of differentiating into unwanted cell types. We report the medium-term to long-term safety of cells derived from human embryonic stem cells (hESC) transplanted into patients. METHODS: In the USA, two prospective phase 1/2 studies were done to assess the primary endpoints safety and tolerability of subretinal transplantation of hESC-derived retinal pigment epithelium in nine patients with Stargardt's macular dystrophy (age >18 years) and nine with atrophic age-related macular degeneration (age >55 years). Three dose cohorts (50,000, 100,000, and 150,000 cells) were treated for each eye disorder. Transplanted patients were followed up for a median of 22 months by use of serial systemic, ophthalmic, and imaging examinations. The studies are registered with ClinicalTrials.gov, numbers NCT01345006 (Stargardt's macular dystrophy) and NCT01344993 (age-related macular degeneration). FINDINGS: There was no evidence of adverse proliferation, rejection, or serious ocular or systemic safety issues related to the transplanted tissue. Adverse events were associated with vitreoretinal surgery and immunosuppression. 13 (72%) of 18 patients had patches of increasing subretinal pigmentation consistent with transplanted retinal pigment epithelium. Best-corrected visual acuity, monitored as part of the safety protocol, improved in ten eyes, improved or remained the same in seven eyes, and decreased by more than ten letters in one eye, whereas the untreated fellow eyes did not show similar improvements in visual acuity. Vision-related quality-of-life measures increased for general and peripheral vision, and near and distance activities, improving by 16-25 points 3-12 months after transplantation in patients with atrophic age-related macular degeneration and 8-20 points in patients with Stargardt's macular dystrophy. INTERPRETATION: The results of this study provide the first evidence of the medium-term to long-term safety, graft survival, and possible biological activity of pluripotent stem cell progeny in individuals with any disease. Our results suggest that hESC-derived cells could provide a potentially safe new source of cells for the treatment of various unmet medical disorders requiring tissue repair or replacement. FUNDING: Advanced Cell Technology.

Five-Year Safety and Performance Results from the Argus II Retinal Prosthesis System Clinical Trial.

PURPOSE: The Argus II Retinal Prosthesis System (Second Sight Medical Products, Inc, Sylmar, CA) was developed to restore some vision to patients blind as a result of retinitis pigmentosa (RP) or outer retinal degeneration. A clinical trial was initiated in 2006 to study the long-term safety and efficacy of the Argus II System in patients with bare or no light perception resulting from end-stage RP. DESIGN: Prospective, multicenter, single-arm clinical trial. Within-patient controls included the nonimplanted fellow eye and patients' native residual vision compared with their vision with the Argus II. PARTICIPANTS: Thirty participants in 10 centers in the United States and Europe. METHODS: The worse-seeing eye of blind patients was implanted with the Argus II. Patients wore glasses mounted with a small camera and a video processor that converted images into stimulation patterns sent to the electrode array on the retina. MAIN OUTCOME MEASURES: The primary outcome measures were safety (the number, seriousness, and relatedness of adverse events) and visual function, as measured by 3 computer-based, objective tests. Secondary measures included functional vision performance on objectively scored real-world tasks. RESULTS: Twenty-four of 30 patients remained implanted with functioning Argus II Systems at 5 years after implantation. Only 1 additional serious adverse event was experienced after the 3-year time point. Patients performed significantly better with the Argus II on than off on all visual function tests and functional vision tasks. CONCLUSIONS: The 5-year results of the Argus II trial support the long-term safety profile and benefit of the Argus II System for patients blind as a result of RP. The Argus II is the first and only retinal implant to have market approval in the European Economic Area, the United States, and Canada.

Long-Term Results from an Epiretinal Prosthesis to Restore Sight to the Blind.

PURPOSE: Retinitis pigmentosa (RP) is a group of inherited retinal degenerations leading to blindness due to photoreceptor loss. Retinitis pigmentosa is a rare disease, affecting only approximately 100 000 people in the United States. There is no cure and no approved medical therapy to slow or reverse RP. The purpose of this clinical trial was to evaluate the safety, reliability, and benefit of the Argus II Retinal Prosthesis System (Second Sight Medical Products, Inc, Sylmar, CA) in restoring some visual function to subjects completely blind from RP. We report clinical trial results at 1 and 3 years after implantation. DESIGN: The study is a multicenter, single-arm, prospective clinical trial. PARTICIPANTS: There were 30 subjects in 10 centers in the United States and Europe. Subjects served as their own controls, that is, implanted eye versus fellow eye, and system on versus system off (native residual vision). METHODS: The Argus II System was implanted on and in a single eye (typically the worse-seeing eye) of blind subjects. Subjects wore glasses mounted with a small camera and a video processor that converted images into stimulation patterns sent to the electrode array on the retina. MAIN OUTCOME MEASURES: The primary outcome measures were safety (the number, seriousness, and relatedness of adverse events) and visual function, as measured by 3 computer-based, objective tests. RESULTS: A total of 29 of 30 subjects had functioning Argus II Systems implants 3 years after implantation. Eleven subjects experienced a total of 23 serious device- or surgery-related adverse events. All were treated with standard ophthalmic care. As a group, subjects performed significantly better with the system on than off on all visual function tests and functional vision assessments. CONCLUSIONS: The 3-year results of the Argus II trial support the long-term safety profile and benefit of the Argus II System for patients blind from RP. Earlier results from this trial were used to gain approval of the Argus II by the Food and Drug Administration and a CE mark in Europe. The Argus II System is the first and only retinal implant to have both approvals.

Long-term natural history of ellipsoid zone width in USH2A-retinopathy.

AIMS: To investigate the long-term natural history of ellipsoid zone (EZ) width in USH2A-retinopathy. METHODS: EZ width measurements from optical coherence tomography were retrospectively obtained from 110 eyes of 55 participants with molecularly confirmed biallelic USH2A-retinopathy. We used a hierarchical Bayesian method to construct and compare different mathematical models describing the long-term decline of EZ width. RESULTS: Compared with linear and quadratic models, exponential decline best represented the long-term loss of EZ width based on the deviance information criterion score. Log-transformed EZ width declined linearly over 30 years of inferred disease duration (median: 0.063 (IQR: 0.040-0.086) log (µm)/year). Compared with the raw EZ width decline rate, the log-transformed EZ width decline rate required 48% fewer patients to achieve an identically powered 1-year trial (38 vs 73 participants). Log EZ width decline rate was uncoupled from baseline EZ width (Spearman ρ=-0.18, p=0.06) and age (ρ=-0.10, p=0.31). Eyes with Usher syndrome exhibited earlier median onset ages of macular EZ width loss (18.8 (IQR: 13.1-24.7) vs 28.1 (IQR: 18.5-35.8) years, p<0.001) but comparable log EZ width decline rates (0.060 (IQR: 0.035-0.100) vs 0.065 (IQR: 0.050-0.079) log (µm)/year; p=0.42). CONCLUSIONS: EZ width follows an exponential decline in USH2A-retinopathy. Compared with raw EZ width decline rate, log-transformed EZ width decline rate may be a superior endpoint for clinical trials. Syndromic eyes exhibit an earlier onset of macular EZ width loss but progress at comparable rates to non-syndromic eyes.