Flow cytometric method for the detection and quantification of retinal cell death and oxidative stress.

Retinal cell death is the major cause of vision loss in many forms of blinding retinal disease. A plethora of research is focused on understanding the mechanisms of retinal cell death to identify potential neuroprotective strategies that prevent vision loss in these diseases. Traditionally, histological techniques have been used to determine the type and extent of cell death in the retina. These techniques, such as TUNEL labeling and immunohistochemistry, are laborious and time consuming, resulting in low throughput and variable results depending on the experimenter. To increase throughput and reduce variability, we developed several flow cytometry-based assays to detect and quantify retinal cell death. The methods and accompanying data presented demonstrate that flow cytometry can readily detect both retinal cell death and oxidative stress and importantly, the efficacy of neuroprotective agents. These methods will be of interest to investigators looking to increase throughput and efficiency without compromising sensitivity as the methods herein reduce analysis time from several months to less than a week. As such, the flow cytometry methods presented have the potential to expedite research efforts focused on developing novel strategies for retinal cell neuroprotection.

Dark-reared rd10 mice experience rapid photoreceptor degeneration with short exposure to room-light during in vivo retinal imaging.

Inherited retinal diseases (IRDs) are a collection of rare genetic conditions, which can lead to complete blindness. A large number of causative genes have been identified for IRDs and while some success has been achieved with gene therapies, they are limited in scope to each individual gene and/or the specific mutation harbored by each patient with an IRD. Multiple studies are underway to elucidate common underlying mechanisms contributing to photoreceptor (PR) loss and to design gene-agnostic, pan-disease therapeutics. The rd10 mouse, which recapitulates slow degeneration of PRs, is an in vivo IRD model used commonly by vision researchers. Light deprivation by rearing animals in complete darkness significantly delays PR death in rd10 mice, subsequently increasing the time window for in vivo studies investigating neuroprotective strategies. Longitudinal in vivo retinal imaging following the same rd10 mice over time is a potential solution for reducing the number of animals required to complete a study. We describe a previously unreported phenotype in the dark-reared rd10 model that is characterized by dramatic PR degeneration following brief exposure to low-intensity light. This exquisite light sensitivity precludes the use of longitudinal studies employing in vivo imaging or other functional assessment requiring room light in rd10 mice and highlights the importance of closely following animal models of IRD to determine any deviations from the expected degeneration curve during routine experimentation.

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.

Synthetic high-density lipoprotein nanoparticles delivering rapamycin for the treatment of age-related macular degeneration.

Synthetic high-density lipoprotein (sHDL) and rapamycin (Rap) have both been shown to be potential treatments for age-related macular degeneration (AMD). The low aqueous solubility of Rap, however, limits its therapeutic utility. Here we used an Apolipoprotein A-I mimetic peptide and phospholipid-based sHDL for the intravitreal delivery of Rap. By incorporation of Rap in sHDL nanoparticles (sHDL-Rap), we achieve 125-fold increase in drug aqueous concentration. When applied in vitro to retinal pigment epithelium cells, sHDL-Rap exhibited the abilities to efflux cholesterol, neutralize endotoxin, and suppress NF-κB activation. As an mTOR inhibitor, Rap induced autophagy and inhibited NF-κB-mediated pro-inflammatory signaling. Additionally, a greater reduction in lipofuscin accumulation and increased anti-inflammatory effects were achieved by sHDL-Rap relative to free drug or sHDL alone. In vivo studies demonstrated that sHDL reached the target retina pigment epithelium (RPE) layer following intravitreal administration in rats. These results suggest that sHDL-Rap holds potential as a treatment for AMD.

Autophagy activation and photoreceptor survival in retinal detachment.

We assess the effect of autophagy inhibition on photoreceptor (PR) survival during experimental retinal detachment (RD) and examine the and examine the relationship between autophagy and the expression of glycolytic enzymes HK2 and PKM2 in the retina. We find that inhibiting autophagy by genetic knock out of the autophagy activator Atg5 in rod PRs resulted in increased apoptotic and necroptotic cell death during RD, demonstrated by elevated terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells, caspase 8 activity, transcript levels of Fas receptor and RIPK3 as compared to controls. The absence of autophagy in rods resulted in downregulation of hexokinase 2 and pyruvate kinase muscle isozyme 2 levels. More than 460 proteins were identified by mass spectroscopy in autophagosomes isolated from detached retinas compared with less than 150 proteins identified in autophagosomes from attached retinas. Among various cellular compartments, proteins from cytoskeleton, cytoplasm and intracellular organelles constituted a large portion of increased autophagosome contents. These proteins represent numerous biological processes, including phototransduction, cell-cell signaling, metabolism and inflammation. Our findings suggest that competent autophagy machinery is necessary for PR homeostasis and improving PR survival during periods of nutrient deprivation.

A novel OCT signature in leukemic papillopathy masquerading as autoimmune or infectious uveitis.

PURPOSE: With therapeutic advances, central nervous system (CNS) involvement in leukemia has become more common. Leukemic optic disc infiltration, often a clinical diagnosis, can present as an isolated finding in primary or relapsed CNS disease and therefore requires early recognition. Not previously well appreciated, we report here signs of intraocular inflammation accompanying leukemic optic disc infiltration, suggesting infectious or non-infectious uveitis as an alternative diagnosis. We describe a novel optical coherence tomography (OCT) sign favoring leukemic infiltration. METHODS: Retrospective consecutive case series of all leukemic patients with disc edema (5 patients, 6 eyes) presenting to the University of Michigan's Ocular Oncology Clinic between October 2019 and March 2020. RESULTS: We report five leukemic patients (6 eyes) who were evaluated for disc edema and vitritis and eventually diagnosed with leukemic papillopathy. All five patients initially had a bland lumbar puncture (LP), and all four patients who underwent magnetic resonance imaging (MRI) had no retrobulbar nerve involvement. Clinical findings included preserved visual acuity (n = 5 eyes, 83%), anterior chamber (AC) cell (n = 3 eyes, 50%), vitreous cell (n = 6 eyes, 100%), and retinal whitening (n = 4 eyes, 66%). In five eyes (83%), a diagnosis of infectious or non-infectious uveitis was initially considered. The OCT finding of inner retinal thickening and loss of inner retinal lamination with largely preserved outer retinal architecture helped point towards a leukemic infiltrative process emanating from the disc and spreading retrograde through the nerve fiber layer. CONCLUSIONS: These cases highlight the difficulty of distinguishing intraocular inflammation associated with leukemic papillopathy from infectious or non-infectious uveitis, especially considering bland LP and negative retrobulbar MRI signal in all our patients. We propose juxtapapillary inner retinal infiltration with the loss of inner retinal lamination and relative preservation of outer retinal architecture on OCT imaging as a finding that supports the diagnosis of leukemic papillopathy.

BACILLARY LAYER DETACHMENT: MULTIMODAL IMAGING AND HISTOLOGIC EVIDENCE OF A NOVEL OPTICAL COHERENCE TOMOGRAPHY TERMINOLOGY: Literature Review and Proposed Theory.

PURPOSE: To clarify the histologic basis of bacillary layer detachment (BALAD) through a review of the current literature and an analysis of retinal imaging. METHODS: The literature for previous reports of BALAD were reviewed. An analysis of retinal images was performed to support anatomical conclusions. RESULTS: A total of 164 unique patients with BALAD on optical coherence tomography (OCT) were identified from the published literature. Twenty-two underlying etiologies, all associated with subretinal exudation, were identified. Forty-one different OCT terminologies were found. The defining OCT feature of BALAD was a split at the level of the photoreceptor inner segment myoid creating a distinctive intraretinal cavity. Resolution of BALAD was followed by a rapid restoration of the ellipsoid zone. Histology of age-related macular degeneration eyes suggests that individual photoreceptors can shed inner segments. Furthermore, detachment of the entire layer of inner segments is a common postmortem artifact. It is proposed that BALAD occurs when outwardly directed forces promoting attachment of photoreceptor outer segments to the retinal pigment epithelium exceed the tensile strength of the photoreceptor inner segment myoid. CONCLUSION: This review serves to strengthen the OCT nomenclature "bacillary layer detachment," based on specific reflectance information obtained by OCT and previously published histologic observations.

Retinal neuroprotection: current strategies and future directions.

PURPOSE OF REVIEW: Photoreceptor cell death is the ultimate cause of vision loss in many retinal disorders. Currently, there are no commercially available treatments to prevent photoreceptor cell loss and preserve vision, and there is a critical unmet need for neuroprotective modalities to improve photoreceptor survival in a multitude of retinal disorders. This review summarizes the literature published on this topic in the last 18 months. RECENT FINDINGS: A plethora of novel therapeutic modalities for photoreceptor neuroprotection have recently been examined in clinical trials for age-related macular degeneration, inherited retinal dystrophies, and macular telangiectasia type 2. These modalities include agents that target the complement pathway, stem cells, gene therapies, and neurotrophic factors. Additionally, improved understanding in the metabolic signals that regulate photoreceptor survival and function may ultimately identify targets for developing novel neuroprotective agents in a multitude of retinal disorders. SUMMARY: Retinal neuroprotection is the next frontier in ophthalmic disease, and the discovery of novel neuroprotective strategies will fill a critical unmet need. Although the clinical utility of existing neuroprotective therapies is still quite limited, we are cautiously optimistic in light of the recent successes described in this review as well as other promising developments.

Smartphone-based fundus photography for screening of plus-disease retinopathy of prematurity.

BACKGROUND: Inadequate screening of treatment-warranted retinopathy of prematurity (ROP) can lead to devastating visual outcomes. Especially in resource-poor communities, the use of an affordable, portable, and easy to use smartphone-based non-contact fundus photography device may prove useful for screening for high-risk ROP. This study evaluates the feasibility of screening for high-risk ROP using a novel smartphone-based fundus photography device, RetinaScope. METHODS: Retinal images were obtained using RetinaScope on a cohort of prematurely born infants during routine examinations for ROP. Images were reviewed by two masked graders who determined the image quality, the presence or absence of plus disease, and whether there was retinopathy that met predefined criteria for referral. The agreement between image-based assessments was compared to the gold standard indirect ophthalmoscopic assessment. RESULTS: Fifty-four eyes of 27 infants were included. A wide-field fundus photograph was obtained using RetinaScope. Image quality was acceptable or excellent in 98% and 95% of cases. There was substantial agreement between the gold standard and photographic assessment of presence or absence of plus disease (Cohen's κ = 0.85). Intergrader agreement on the presence of any retinopathy in photographs was also high (κ = 0.92). CONCLUSIONS: RetinaScope can capture digital retinal photographs of prematurely born infants with good image quality for grading of plus disease.

Management of Peripapillary Choroidal Neovascular Membrane in Patients With Idiopathic Intracranial Hypertension.

OBJECTIVE: To report the clinical features and treatment outcomes of patients with peripapillary choroidal neovascular membrane (CNVM) secondary to idiopathic intracranial hypertension (IIH). METHODS: Retrospective, multicenter chart review of patients diagnosed with peripapillary CNVM in the course of the treatment and follow-up of IIH. RESULTS: Records were reviewed from 7 different institutions between 2006 and 2016. Ten patients (13 eyes) with a diagnosis of IIH and at least 3 months of follow-up developed CNVM. Three of the total 10 patients developed bilateral CNVM. The mean time from the diagnosis of IIH to CNVM diagnosis was 41 months. Mean follow-up period was 8 months after diagnosis of CNVM. All patients were treated with acetazolamide for IIH. Seven eyes were observed, and 6 eyes were given anti-vascular endothelial growth factor (anti-VEGF) injections, including bevacizumab, ranibizumab, and aflibercept. All CNVMs regressed with subretinal fibrosis, and visual acuity improved in most patients. Papilledema resolved in only 1 eye, while the other 12 eyes had persistent papilledema at last follow-up. CONCLUSIONS: Peripapillary CNVM, a rare complication of IIH, often resolves spontaneously with treatment of IIH. In vision-threatening and/or persistent cases, intravitreal anti-VEGF treatment may be a safe and effective therapeutic option.

NOVEL CLASSIFICATION SYSTEM FOR COMBINED HAMARTOMA OF THE RETINA AND RETINAL PIGMENT EPITHELIUM.

PURPOSE: To develop an anatomical classification scheme for combined hamartoma of the retina and retinal pigment epithelium (RPE) and specify recommendations for follow-up interval. METHODS: Retrospective review of patients with combined hamartoma of the retina and RPE examined during a 7-year period (2008-2015). The clinical presentation, fundus examination, and optical coherence tomography were analyzed. RESULTS: Lesions were classified based on location, fundus features, and optical coherence tomography findings. Lesion location: macular/peripapillary-Zone 1; mid-periphery-Zone 2; and far periphery-Zone 3. Associated fundus findings: no retinal traction-Stage 1; retinal traction and/or retinoschisis-Stage 2; and retinal detachment-Stage 3. Optical coherence tomography findings: epiretinal component only-A; partial retinal involvement-B; and complete retinal and RPE involvement-C. Complete ophthalmologic evaluation is recommended at least every 6 months for patients younger than 12 years, with more frequent follow-up in patients with: lesions in the macula/peripapillary (Zone 1) or with retinal traction, retinoschisis, or retinal detachment (Stage 2 and 3). Surgical intervention is recommended in patients with vision loss secondary to macular traction or retinal detachment. CONCLUSION: A new clinical classification system is proposed for evaluating and managing patients with combined hamartoma of the retina and RPE. The zone and stage of combined hamartoma of the retina and RPE lesion will assist in determining follow-up interval and surgical intervention. Application of a uniform classification scheme will facilitate assessment and comparison of findings across different studies.

Growth Kinetics in Layer-by-Layer Assemblies of Organic Nanoparticles and Polyelectrolytes.

The growth rates of layer-by-layer (LbL) assemblies of polyelectrolytes (PEs) with oppositely charged polystyrene (PS) nanoparticles (NPs) as a function of molecular weight (MW) of the PEs, ionic strength of the media, and NP size and charge are systematically investigated. To optimize LbL growth, the effects of suspension concentration, pH of the media, and deposition time on the growth rate of multilayers are assessed. Both linear and exponential growth behaviors are observed and, under optimal conditions, films of up to around 1 µm thick can readily be assembled after 10 or so bilayers have been deposited. For many of the cases studied, an intermediate MW of PE leads to the fastest film buildup, for both cationic poly(ethyleneimine) deposited alternately with anionic PS NPs and for anionic poly(acrylic acid) deposited alternately with cationic PS NPs. The existence of an optimal MW suggests that growth rate is determined by a balance of thermodynamic factors, including density of polymer bridges between particles, and kinetic factors, specifically the diffusivity of polymer in the film. The optimal MW, however, is very sensitive to the materials used. Moreover, depending on the MW of the PE, increasing salinity could increase or decrease the growth kinetics. Finally, the surface morphology of the films is characterized with AFM and SEM to reveal that the roughness increases less than linearly with film thickness.

Predictors of Photographic Quality with a Handheld Nonmydriatic Fundus Camera Used for Screening of Vision-Threatening Diabetic Retinopathy.

PURPOSE: To analyze predictors of image quality for a handheld nonmydriatic fundus camera used for screening of vision-threatening diabetic retinopathy. METHODS: An ophthalmic photographer at an Aravind Eye Hospital obtained nonmydriatic and mydriatic fundus images from 3 fields in 275 eyes of 155 participants over 13 months using a Smartscope camera (Optomed, Oulu, Finland) and a Topcon tabletop fundus camera (Topcon, Tokyo, Japan). Two fellowship-trained retina specialists graded the images. Repeated-measures logistic regression assessed predictors of the main outcome measure: gradability of the fundus images. RESULTS: Of 2,475 images, 76.2% of the Smartscope nonmydriatic images, 90.1% of the Smartscope mydriatic images, and 92.0% of the Topcon mydriatic images were gradable. Eyes with vitreous hemorrhage (OR = 0.24, p < 0.0001) or advanced cataract (OR = 0.08, p < 0.0001) had decreased odds of image gradability. Excluding eyes with cataract or vitreous hemorrhage, nonmydriatic macular image gradability improved from 68.4% in the first set of 55 eyes to 94.6% in the final set of 55 eyes. CONCLUSION: With sufficient training, paraprofessional health care staff can obtain high-quality images with a portable nonmydriatic fundus camera, particularly in patients with clear lenses and clear ocular media.

Pharmacotherapies for Retinal Detachment.

Retinal detachment is an important cause of visual loss. Currently, surgical techniques, including vitrectomy, scleral buckle, and pneumatic retinopexy, are the only means to repair retinal detachment and restore vision. However, surgical failure rates may be as high as 20%, and visual outcomes continue to vary secondary to multiple processes, including postoperative cystoid macular edema, epiretinal membrane formation, macular folds, and, ultimately, photoreceptor death. Therefore, pharmacotherapies are being sought to aid the success rates of modern surgical techniques and reduce or slow the degeneration of photoreceptors during retinal detachment. This review discusses potential therapeutic avenues that aid in retinal reattachment, reduce the rate of retinal redetachment by limiting proliferative vitreoretinopathy, and protect against photoreceptor cell death.

Evaluation of Screening for Retinopathy of Prematurity by ROPtool or a Lay Reader.

PURPOSE: To determine if (1) tortuosity assessment by a computer program (ROPtool, developed at the University of North Carolina, Chapel Hill, and Duke University, and licensed by FocusROP) that traces retinal blood vessels and (2) assessment by a lay reader are comparable with assessment by a panel of 3 retinopathy of prematurity (ROP) experts for remote clinical grading of vascular abnormalities such as plus disease. DESIGN: Validity and reliability analysis of diagnostic tools. PARTICIPANTS: Three hundred thirty-five fundus images of prematurely born infants. METHODS: Three hundred thirty-five fundus images of prematurely born infants were obtained by neonatal intensive care unit nurses. A panel of 3 ROP experts graded 84 images showing vascular dilatation, tortuosity, or both and 251 images showing no evidence of vascular abnormalities. These images were sent electronically to an experienced lay reader who independently graded them for vascular abnormalities. The images also were analyzed using the ROPtool, which assigns a numerical value to the level of vascular abnormality and tortuosity present in each of 4 quadrants or sectors. The ROPtool measurements of vascular abnormalities were graded and compared with expert panel grades with a receiver operating characteristic (ROC) curve. Grades between human readers were cross-tabulated. The area under the ROC curve was calculated for the ROPtool, and sensitivity and specificity were computed for the lay reader. MAIN OUTCOME MEASURES: Measurements of vascular abnormalities by ROPtool and grading of vascular abnormalities by 3 ROP experts and 1 experienced lay reader. RESULTS: The ROC curve for ROPtool's tortuosity assessment had an area under the ROC curve of 0.917. Using a threshold value of 4.97 for the second most tortuous quadrant, ROPtool's sensitivity was 91% and its specificity was 82%. Lay reader sensitivity and specificity were 99% and 73%, respectively, and had high reliability (κ, 0.87) in repeated measurements. CONCLUSIONS: ROPtool had very good accuracy for detection of vascular abnormalities suggestive of plus disease when compared with expert physician graders. The lay reader's results showed excellent sensitivity and good specificity when compared with those of the expert graders. These options for remote reading of images to detect vascular abnormalities deserve consideration in the quest to use telemedicine with remote reading for efficient delivery of high-quality care and to detect infants requiring bedside examination.

Vision Loss After Central Retinal Artery Occlusion Secondary to Orbital Sarcoid Mass.

The authors describe the first report in the literature of central retinal artery occlusion as the presenting manifestation of sarcoidosis. A 33-year-old man with asthma, headache, and 6 days of intermittent, transient vision loss in the OS presented with persistent vision loss in the OS. Ophthalmic examination was consistent with diagnosis of central retinal artery occlusion in the OS. Vascular imaging with CT angiography revealed an incidental finding of an intraconal mass surrounding the left optic nerve and hilar lymphadenopathy. Broncho scopic lymph node biopsy demonstrated noncaseating granulomas consistent with sarcoidosis. This case proffers a unique mechanism of vision loss in sarcoidosis and highlights that atypical causes of central retinal artery occlusion must be considered in patients without typical risk factors.

Risk factors associated with developing branch retinal vein occlusion among enrollees in a United States managed care plan.

PURPOSE: To determine risk factors associated with development of a branch retinal vein occlusion (BRVO) among a large group of managed-care plan beneficiaries in the United States. DESIGN: Retrospective, longitudinal cohort study. PARTICIPANTS: All beneficiaries age ≥55 years continuously enrolled for ≥2 years in a managed care network from 2001-2009 who had ≥2 visits to an eye care provider. METHODS: Multivariable Cox regression analyses identified sociodemographic factors, ocular and nonocular conditions associated with incident BRVO. MAIN OUTCOME MEASURES: Hazard of incident BRVO with 95% confidence interval (CI). RESULTS: Of the 492,488 enrollees who met inclusion criteria, 2283 (0.5%) developed incident BRVO. After adjustment for confounding factors, blacks (adjusted hazard ratio [aHR], 1.43; CI, 1.19-1.73; P = 0.0001) had a 43% increased hazard of BRVO relative to non-Hispanic whites. Enrollees with hypertension (HTN) alone (aHR, 1.78; CI, 1.36-2.32; P < 0.0001) or HTN along with other metabolic syndrome components (diabetes mellitus [DM] and hyperlipidemia; aHR, 1.44; CI, 1.12-1.84; P = 0.005) had an increased hazard of developing a BRVO compared with those with none of these conditions. Disease severity was important; enrollees with end-organ damage caused by HTN had a 107% increased hazard of developing BRVO compared with enrollees without HTN (aHR, 2.07; CI, 1.75-2.45; P < 0.0001). Although there was no association between DM without end-organ damage and BRVO (aHR, 0.92; CI, 0.81-1.04; P = 0.2), individuals with end-organ damage from DM had a 36% increased hazard of BRVO (aHR, 1.36; CI, 1.18-1.57; P < 0.0001) compared with those without DM. Although cerebrovascular accident was associated with an increased hazard of developing BRVO (aHR, 1.34; CI, 1.19-1.52; P < 0.0001), other diseases of the vascular system (deep venous thrombosis/pulmonary embolism, peripheral vascular disease, hypercoagulable state, myocardial infarction) or anticoagulant use did not increase the risk of BRVO (P > 0.10 for all comparisons). CONCLUSIONS: Both HTN and end-organ damage from DM contribute to arteriosclerosis, atherosclerosis, and endothelial dysfunction, which seem to be major risk factors for BRVO. Ophthalmologists should emphasize to patients and their primary physicians the importance of effectively managing systemic medical conditions associated with BRVO.

Retinal cell death and current strategies in retinal neuroprotection.

PURPOSE OF REVIEW: Retinal cell death is the main cause of vision loss in many blinding conditions. Research on the basics of how and why retinal cells die in different diseases provides insights into the development of treatment strategies to prevent or reverse this loss. This review summarizes the literature published on this topic in the last year. RECENT FINDINGS: Apoptosis is generally considered the main pathway by which retinal cells die in response to a range of noxious stimuli. However, inhibiting apoptosis does not completely prevent retinal cell death, as many enter programmed necrosis or necroptosis. Many novel ways of inhibiting apoptosis and necrosis, including blockage of the Fas receptor, neuroprotective peptides and antioxidants, continue to be investigated. Also, additional pathways including autophagy and inflammation are being examined on how they contribute to the loss of retinal cells in different disease models. SUMMARY: With more knowledge of how retinal cells die, further advances are being made in prolonging the cell survival. However, even as basic science discoveries remain promising, clinical utility of neuroprotection is still quite limited at this time.

Classification and Growth Rate of Chorioretinal Atrophy after Voretigene Neparvovec-Rzyl for RPE65-Mediated Retinal Degeneration.

PURPOSE: Classify the appearance and quantify the growth rate of chorioretinal atrophy in patients who received voretigene neparvovec-rzyl (VN) for RPE65-mediated retinal degeneration. DESIGN: Multicenter retrospective analysis. SUBJECTS: Patients who underwent subretinal VN injection at 5 institutions and demonstrated posterior-pole chorioretinal atrophy. METHODS: Ultrawidefield scanning laser ophthalmoscopy or color fundus photos were assessed before and after subretinal VN. Atrophy was defined as regions with ≥ 2 of the following: (1) partial or complete retinal pigment epithelial depigmentation; (2) round shape; (3) sharp margins; and (4) increased visibility of choroidal vessels. Atrophy was qualitatively classified into different subtypes. All atrophy was manually segmented. Linear mixed-effects models with random slopes and intercepts were fit using atrophy area and square root of atrophy area. MAIN OUTCOME MEASURES: Number of eyes with each atrophy pattern, and slopes of linear mixed-effects models. RESULTS: Twenty-seven eyes from 14 patients across 5 centers developed chorioretinal atrophy after subretinal VN. A mean of 5.8 ± 2.7 images per eye obtained over 2.2 ± 0.8 years were reviewed, and atrophy was categorized into touchdown (14 eyes), nummular (15 eyes), and perifoveal (12 eyes) subtypes. Fifteen eyes demonstrated > 1 type of atrophy. Thirteen of 14 patients demonstrated bilateral atrophy. The slopes of the mixed-effects models of atrophy area and square root of atrophy area (estimate ± standard error) were 1.7 ± 1.3 mm2/year and 0.6 ± 0.2 mm/year for touchdown atrophy, 5.5 ± 1.3 mm2/year and 1.2 ± 0.2 mm/year for nummular atrophy, and 16.7 ± 1.8 mm2/year and 2.3 ± 0.2 mm/year for perifoveal atrophy. The slopes for each type of atrophy were significantly different in the square root of atrophy model, which best fit the data (P < 0.05). CONCLUSIONS: Chorioretinal atrophy after subretinal VN for RPE65-mediated retinal degeneration developed according to a touchdown, nummular, and/or perifoveal pattern. Perifoveal atrophy grew the most rapidly, while touchdown atrophy grew the least rapidly. Understanding the causes of these findings, which are present in a minority of patients, merits further investigation. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.