Harrison WJ, Bex PJ. Integrating retinotopic features in spatiotopic coordinates. J Neurosci 2014;34(21):7351-60.Abstract
The receptive fields of early visual neurons are anchored in retinotopic coordinates (Hubel and Wiesel, 1962). Eye movements shift these receptive fields and therefore require that different populations of neurons encode an object's constituent features across saccades. Whether feature groupings are preserved across successive fixations or processing starts anew with each fixation has been hotly debated (Melcher and Morrone, 2003; Melcher, 2005, 2010; Knapen et al., 2009; Cavanagh et al., 2010a,b; Morris et al., 2010). Here we show that feature integration initially occurs within retinotopic coordinates, but is then conserved within a spatiotopic coordinate frame independent of where the features fall on the retinas. With human observers, we first found that the relative timing of visual features plays a critical role in determining the spatial area over which features are grouped. We exploited this temporal dependence of feature integration to show that features co-occurring within 45 ms remain grouped across eye movements. Our results thus challenge purely feedforward models of feature integration (Pelli, 2008; Freeman and Simoncelli, 2011) that begin de novo after every eye movement, and implicate the involvement of brain areas beyond early visual cortex. The strong temporal dependence we quantify and its link with trans-saccadic object perception instead suggest that feature integration depends, at least in part, on feedback from higher brain areas (Mumford, 1992; Rao and Ballard, 1999; Di Lollo et al., 2000; Moore and Armstrong, 2003; Stanford et al., 2010).
Haruta M, Arai M, Sueda J, Hirose T, Yamakawa R. Patching retinal breaks with Seprafilm for treating retinal detachments in humans: 9 years of follow-up. Eye (Lond) 2017;31(5):776-780.Abstract
PurposeTo describe the long-term surgical outcomes of four patients treated for retinal detachment using Seprafilm as a novel technique.MethodsRetinal breaks in four eyes were covered with Seprafilm using a transvitreal approach after cataract surgery, pars plana vitrectomy, fluid-air exchange, and laser photocoagulation. Neither long-standing gas nor silicone oil was used. The patients were not instructed to maintain a specific head positioning postoperatively.ResultsSuccessful retinal reattachment was achieved with a single surgery in all four eyes, and none developed proliferative vitreoretinopathy. The mean best-corrected visual acuity preoperatively and 9 years postoperatively were 20/97 and 20/33, respectively. The intraocular pressure increased several days postoperatively that lasted no longer than 2 weeks. Visual field defects either in the inferonasal or inferotemporal quadrant were detected postoperatively. The mean electroretinogram a- and b-wave amplitude ratios of the operated eyes to the fellow eyes were 0.68 and 0.64 preoperatively and 0.87 and 0.92 postoperatively, respectively. The mean corneal endothelial cell density was 2365 cells/mm(2) preoperatively and 2592 cells/mm(2) postoperatively.ConclusionCovering retinal breaks with Seprafilm may promote retinal reattachment without gas tamponade and postoperative head positioning. The visual outcomes 9 years postoperatively showed no apparent adverse effects of intraocular application of Seprafilm.
PURPOSE: To investigate choroidal involvement in acute posterior multifocal placoid pigment epitheliopathy (APMPPE). METHODS: A retrospective observational case series using multimodal imaging including optical coherence tomography (OCT) angiography. RESULTS: Five patients with APMPPE were included. In most acute lesions, OCT angiography revealed outer retinal and retinal pigment epithelium (RPE) hyperreflective lesions with attenuated OCT signal in the underlying choroid, but careful examination allowed us to identify a single lesion with decreased choriocapillaris flow outside the signal attenuation. Optical coherence tomography angiography obtained after healing of lesions revealed areas of hypointense circular flow voids clustered in groups surrounded by either isointense or hyperintense signal background. Point-by-point evaluation revealed these flow voids did not correspond to areas of RPE thickening or focal pigmentary changes. Larger hypointense lesions were observed and did correlate with pigmentary changes. CONCLUSION: Our case series demonstrates choriocapillaris flow abnormalities in acute APMPPE extending beyond the OCT lesions, and distinct residual vascular abnormalities in healed APMPPE lesions on OCT angiography. Our findings support a primary ischemic insult to the photoreceptors and RPE, but choriocapillaris flow abnormalities could be secondary to (OCT invisible) retinal and RPE involvement. The lack of understanding of the etiology along with the inability to visualize most of the choroid in acute lesions precludes definite conclusions about the true pathogenesis of APMPPE.
Hellgren G, Löfqvist C, Hansen-Pupp I, Gram M, Smith LE, Ley D, Hellström A. Increased postnatal concentrations of pro-inflammatory cytokines are associated with reduced IGF-I levels and retinopathy of prematurity. Growth Horm IGF Res 2018;39:19-24.Abstract
OBJECTIVE: Retinopathy of prematurity (ROP) is a multifactorial disease linked to low insulin-like growth factor (IGF)-I levels and perhaps to postnatal inflammation. Here, we investigated the longitudinal postnatal serum concentrations of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in relation to IGF-I levels and ROP. DESIGN: The study cohort included 52 infants born before 31 gestational weeks. The infants were screened for ROP and classified as non-ROP (n=33), non-proliferative ROP (stages 1 and 2; n=10), or proliferative ROP (stage 3, all treated for ROP; n=9). Blood samples were collected at birth, 24h after birth, and then weekly until at least 36weeks postmenstrual age (PMA) (i.e., up to 13weeks after birth). Circulating levels of IL-6 and TNF-α were evaluated in relation to circulating IGF-I levels and ROP. RESULTS: IL-6 levels negatively correlated with IGF-I levels between 5 and 8weeks after birth, (p<0.01 to p<0.05). At birth, the IL-6 and TNF-α levels were similar independent of later ROP. Twenty-four hours after birth, both IL-6 and TNF-α levels had increased in infants later treated for ROP (p<0.05). Postnatal, infants treated for ROP had higher IL-6 levels than infants without ROP. CONCLUSIONS: The pro-inflammatory response is associated with low IGF-I levels and the development of ROP.
Hellgren G, Löfqvist C, Hård A-L, Hansen-Pupp I, Gram M, Ley D, Smith LE, Hellström A. Serum concentrations of vascular endothelial growth factor in relation to retinopathy of prematurity. Pediatr Res 2015;Abstract

BACKGROUND: The role of VEGF in the pathogenesis of retinopathy of prematurity (ROP) has been clearly established. However, little is known about temporal changes in circulating VEGF concentrations in the preterm infant. The objective was to determine the longitudinal serum concentrations of VEGF in relation to ROP. METHODS: This study included 52 infants born at <31 weeks gestational age (non-ROP n=33, non-proliferative ROP n=10, treated for ROP n=9). VEGF concentrations were analyzed in blood samples collected at birth, at 3 days postnatal age, and then weekly until at least a gestational age of 35 weeks. RESULTS: VEGF concentrations at birth did not differ between groups, independent of later ROP status. In contrast, VEGF serum concentrations were significantly higher at first detection of ROP in infants who were later treated for ROP compared to infants without ROP. At the time of laser therapy, serum VEGF concentrations did not differ between groups. CONCLUSION: Circulatory concentrations of VEGF, in infants who later developed severe ROP, were elevated at the time when ROP first was detected but not at the time when current treatment most often occurred. This supports the need for further studies of circulating VEGF in relation to the timing of ROP treatment.Pediatric Research (2015); doi:10.1038/pr.2015.181.

Hellström A, Pivodic A, Gränse L, Lundgren P, Sjöbom U, Nilsson AK, Söderling H, Hård A-L, Smith LEH, Löfqvist CA. Association of Docosahexaenoic Acid and Arachidonic Acid Serum Levels With Retinopathy of Prematurity in Preterm Infants. JAMA Netw Open 2021;4(10):e2128771.Abstract
Importance: Supplementing preterm infants with long-chain polyunsaturated fatty acids (LC-PUFA) has been inconsistent in reducing the severity and incidence of retinopathy of prematurity (ROP). Furthermore, few studies have measured the long-term serum lipid levels after supplementation. Objective: To assess whether ROP severity is associated with serum levels of LC-PUFA, especially docosahexaenoic acid (DHA) and arachidonic acid (AA), during the first 28 postnatal days. Design, Setting, and Participants: This cohort study analyzed the Mega Donna Mega study, a randomized clinical trial that provided enteral fatty acid supplementation at 3 neonatal intensive care units in Sweden. Infants included in this cohort study were born at a gestational age of less than 28 weeks between December 20, 2016, and August 6, 2019. Main Outcomes and Measures: Severity of ROP was classified as no ROP, mild or moderate ROP (stage 1-2), or severe ROP (stage 3 and type 1). Serum phospholipid fatty acids were measured through gas chromatography-mass spectrometry. Ordinal logistic regression, with a description of unadjusted odds ratio (OR) as well as gestational age- and birth weight-adjusted ORs and 95% CIs, was used. Areas under the curve were used to calculate mean daily levels of fatty acids during postnatal days 1 to 28. Blood samples were obtained at the postnatal ages of 1, 3, 7, 14, and 28 days. Results: A total of 175 infants were included in analysis. Of these infants, 99 were boys (56.6%); the median (IQR) gestational age was 25 weeks 5 days (24 weeks 3 days to 26 weeks 6 days), and the median (IQR) birth weight was 785 (650-945) grams. A higher DHA proportion was seen in infants with no ROP compared with those with mild or moderate ROP or severe ROP (OR per 0.5-molar percentage increase, 0.49 [95% CI, 0.36-0.68]; gestational age- and birth weight-adjusted OR, 0.66 [95% CI, 0.46-0.93]). The corresponding adjusted OR for AA levels per 1-molar percentage increase was 0.83 (95% CI, 0.66-1.05). The association between DHA levels and ROP severity appeared only in infants with sufficient AA levels, suggesting that a mean daily minimum level of 7.8 to 8.3 molar percentage of AA was necessary for a detectable association between DHA level and less severe ROP. Conclusions and Relevance: This cohort study found that higher mean daily serum levels of DHA during the first 28 postnatal days were associated with less severe ROP even after adjustment for known risk factors, but only in infants with sufficiently high AA levels. Further studies are needed to identify LC-PUFA supplementation strategies that may prevent ROP and other morbidities.
Hicks PM, Haaland B, Feehan M, Crandall AS, Pettey JH, Nuttall E, Self W, Hartnett ME, Bernstein P, Vitale A, Shakoor A, Shulman JP, Sieminski SF, Kim I, Owen LA, Murtaugh MA, Noyes A, Deangelis MM. Systemic Disease and Ocular Comorbidity Analysis of Geographically Isolated Federally Recognized American Indian Tribes of the Intermountain West. J Clin Med 2020;9(11)Abstract
BACKGROUND: The American Indian Navajo and Goshute peoples are underserved patient populations residing in the Four Corners area of the United States and Ibupah, Utah, respectively. METHODS: We conducted a cross-sectional study of epidemiological factors and lipid biomarkers that may be associated with type II diabetes, hypertension and retinal manifestations in tribal and non-tribal members in the study areas (n = 146 participants). We performed multivariate analyses to determine which, if any, risk factors were unique at the tribal level. Fundus photos and epidemiological data through standardized questionnaires were collected. Blood samples were collected to analyze lipid biomarkers. Univariate analyses were conducted and statistically significant factors at < 0.10 were entered into a multivariate regression. RESULTS: Of 51 participants for whom phenotyping was available, from the Four Corners region, 31 had type II diabetes (DM), 26 had hypertension and 6 had diabetic retinopathy (DR). Of the 64 participants from Ibupah with phenotyping available, 20 had diabetes, 19 had hypertension and 6 had DR. Navajo participants were less likely to have any type of retinopathy as compared to Goshute participants (odds ratio (OR) = 0.059; 95% confidence interval (CI) = 0.016-0.223; < 0.001). Associations were found between diabetes and hypertension in both populations. Older age was associated with hypertension in the Four Corners, and the Navajo that reside there on the reservation, but not within the Goshute and Ibupah populations. Combining both the Ibupah, Utah and Four Corners study populations, being American Indian ( = 0.022), residing in the Four Corners ( = 0.027) and having hypertension ( < 0.001) increased the risk of DM. DM ( < 0.001) and age ( = 0.002) were significantly associated with hypertension in both populations examined. When retinopathy was evaluated for both populations combined, hypertension ( = 0.037) and living in Ibupah ( < 0.001) were associated with greater risk of retinopathy. When combining both American Indian populations from the Four Corners and Ibupah, those with hypertension were more likely to have DM ( < 0.001). No lipid biomarkers were found to be significantly associated with any disease state. CONCLUSIONS: We found different comorbid factors with retinal disease outcome between the two tribes that reside within the Intermountain West. This is indicated by the association of tribe and with the type of retinopathy outcome when we combined the populations of American Indians. Overall, the Navajo peoples and the Four Corners had a higher prevalence of chronic disease that included diabetes and hypertension than the Goshutes and Ibupah. To the best of our knowledge, this is the first study to conduct an analysis for disease outcomes exclusively including the Navajo and Goshute tribe of the Intermountain West.
Hikage F, Lennikov A, Mukwaya A, Lachota M, Ida Y, Utheim TP, Chen DF, Huang H, Ohguro H. NF-κB activation in retinal microglia is involved in the inflammatory and neovascularization signaling in laser-induced choroidal neovascularization in mice. Exp Cell Res 2021;403(1):112581.Abstract
PURPOSE: To evaluate Nuclear Factor NF-κB (NF-κB) signaling on microglia activation, migration, and angiogenesis in laser-induced choroidal neovascularization (CNV). METHODS: Nine-week-old C57BL/6 male mice were randomly assigned to IMD-0354 treated or untreated groups (5 mice, 10 eyes per group). CNV was induced with a 532-nm laser. Laser spots (power 250 mW, spot size 100 μm, time of exposure 50 ms) were created in each eye using a slit-lamp delivery system. Selective inhibitor of nuclear factor kappa-B kinase subunit beta (IKK2) inhibitor IMD-0354 (10 μg) was delivered subconjunctivally; vehicle-treated mice were the control. The treatment effect on CNV development was assessed at five days post-CNV induction in vivo in C57BL/6 and Cx3cr1gfp/wt mice by fluorescent angiography, fundus imaging, and ex vivo by retinal flatmounts immunostaining and Western blot analysis of RPE/Choroidal/Scleral complexes (RCSC) lysates. In vitro evaluations of IMD-0354 effects were performed in the BV-2 microglial cell line using lipopolysaccharide (LPS) stimulation. RESULTS: IMD-0354 caused a significant reduction in the fluorescein leakage and size of the laser spot, as well as a reduction in microglial cell migration and suppression of phospho-IκBα, Vascular endothelial growth factor (VEGF-A), and Prostaglandin-endoperoxide synthase 2 (COX-2). In vivo and ex vivo observations demonstrated reduced lesion size in mice, CD68, and Allograft inflammatory factor 1 (IBA-1) positive microglia cells migration to the laser injury site in IMD-0354 treated eyes. The data further corroborate with GFP-positive cells infiltration of the CNV site in Cx3cr1wt/gfp mice. In vitro IMD-0354 (10-25 ng/ml) treatment reduced NF-κB activation, expression of COX-2, caused decreased Actin-F presence and organization, resulting in reduced BV-2 cells migration capacity. CONCLUSION: The present data indicate that NF-κB activation in microglia and it's migration capacity is involved in the development of laser CNV in mice. Its suppression by NF-κB inhibition might be a promising therapeutic strategy for wet AMD.
Hong EH, Shin YU, Bae GH, Choi Y, Ahn SJ, Sobrin L, Hong R, Kim I, Cho H. Nationwide incidence and treatment pattern of retinopathy of prematurity in South Korea using the 2007-2018 national health insurance claims data. Sci Rep 2021;11(1):1451.Abstract
The aim of this study is to investigate the nationwide incidence and treatment pattern of retinopathy of prematurity (ROP) in South Korea. Using the population-based National Health Insurance database (2007-2018), the nationwide incidence of ROP among premature infants with a gestational age (GA) < 37 weeks (GA < 28 weeks, GA28; 28 weeks ≤ GA < 37 weeks; GA28-37) and the percentage of ROP infants who underwent treatment [surgery (vitrectomy, encircling/buckling); retinal ablation (laser photocoagulation, cryotherapy)] were evaluated. We identified 141,964 premature infants, 42,300 of whom had ROP, with a nationwide incidence of 29.8%. The incidence of ROP in GA28 group was 4.3 times higher than in GA28-37 group (63.6% [2240/3522] vs 28.9% [40,060/138,442], p < 0.001). As for the 12-year trends, the incidence of ROP decreased from 39.5% (3308/8366) in 2007 to 23.5% (2943/12,539) in 2018. 3.0% of ROP infants underwent treatment (25.0% in GA28; 1.7% in GA28-37); 0.2% (84/42,300) and 2.9% (1214/42,300) underwent surgery and retinal ablation, respectively. The overall percentage of ROP infants who underwent treatment has decreased from 4.7% in 2007 to 1.8% in 2018. This first Korean nationwide epidemiological study of ROP revealed a decreased incidence of ROP and a decreased percentage of ROP infants undergoing conventional treatment during a 12-year period.
Hong GJ, Koerner JC, Weinert MC, Stinnett SS, Freedman SF, Wallace DK, Riggins WJ, Gallaher KJ, Prakalapakorn GS. Quantitatively comparing weekly changes in retinal vascular characteristics of eyes eventually treated versus not treated for retinopathy of prematurity. J AAPOS 2021;Abstract
PURPOSE: To quantitatively compare retinal vascular characteristics over time in eyes eventually treated versus not treated for retinopathy of prematurity (ROP), using ROPtool analysis of narrow-field retinal images. METHODS: This longitudinal study used prospectively collected narrow-field retinal images of infants screened for ROP, prior to treatment, if needed. Images were analyzed using a methodology that combines quadrant-level measures from several images of the same eye. For the longitudinal analysis, one examination per postmenstrual age (PMA) was included per eye. We compared the following ROPtool indices and their change per week between eyes eventually treated versus not treated for ROP: tortuosity index (TI), dilation index (DI), sum of adjusted indices (SAI), and tortuosity-weighted plus (TWP). Analysis was performed on three levels: eye (mean value/eye), quadrant (highest quadrant value/eye), and blood vessel (highest blood vessel value/eye). RESULTS: Of 832 examinations (99 infants), 745 images (89.5%) had 3-4 quadrants analyzable by ROPtool. On the eye level, ROPtool indices differed between eyes eventually treated versus not treated at PMA of 33-35 and 37 weeks for TI, SAI, and TWP, and at PMA of 33-34 and 37 weeks for DI (P ≤ 0.0014), and change per week differed between eyes eventually treated versus not treated only for SAI at PMA of 32 weeks (P < 0.001). CONCLUSIONS: Quantitative analysis of retinal vascular characteristics using ROPtool can help predict eventual need for treatment for ROP as early as 32 weeks PMA. ROPtool index values were more useful than change in these indices to predict eyes that would eventually need treatment for ROP.
Hoshi S, Okamoto F, Arai M, Hirose T, Sugiura Y, Murakami T, Oshika T. Patching retinal breaks with polyethylene glycol-based synthetic hydrogel sealant for retinal detachment in rabbits. Exp Eye Res 2018;177:117-121.Abstract
The purpose of this study was to evaluate absorbable polyethylene glycol (PEG)-based synthetic hydrogel as a sealant for retinal breaks in rhegmatogenous retinal detachment (RD). A three-port, 25-gauge vitrectomy was performed on nine Dutch pigmented rabbit eyes. Subsequently, RD was induced by creating a retinal break. The retina was then reattached by fluid-air exchange. In six of nine eyes (RD-PEG group), PEG sealant was applied to completely cover the retinal breaks, and then photopolymerized with light; thereafter, intravitreous air was replaced with balanced salt solution (BSS). In the remaining three eyes (RD group), PEG sealant was not applied, but the intravitreous air was replaced with BSS. Ophthalmological examinations and intraocular pressure measurements were conducted preoperatively, and at 1 and 7 days, and 1, 3, and 6 months postoperatively. Histological examinations of the eyes were performed after 6 postoperative months. At surgery, retinal reattachment with PEG sealant was achieved in all eyes in the RD-PEG group. Fundoscopic and optical coherence tomographic examinations revealed that the retina remained attached in all the eyes of the RD-PEG group throughout the 6-month observation period. Histological examination revealed no signs of damage in the retinal layers at the edges of the retinal breaks that were in contact with the sealant. In the RD group, the retinas detached in all eyes within 7 days postoperatively. The PEG sealant closed the retinal breaks and maintained retinal reattachment. Intraocular tamponade was not necessary.
Hoshi S, Okamoto F, Arai M, Hirose T, Sugiura Y, Kaji Y, Oshika T. In Vivo and In Vitro Feasibility Studies of Intraocular Use of Polyethylene Glycol-Based Synthetic Sealant to Close Retinal Breaks in Porcine and Rabbit Eyes. Invest Ophthalmol Vis Sci 2015;56(8):4705-11.Abstract

PURPOSE: Absorbable polyethylene glycol-based synthetic sealant (PEG sealant) polymerizes under xenon illumination and forms a clear, flexible, and firmly adherent hydrogel. The intraocular biocompatibility of PEG sealant and efficacy for closing retinal breaks were evaluated. METHODS: In an in vitro study, retinal detachment with a tear was created in porcine eyecups after vitreous gel removal. Polyethylene glycol-based synthetic sealant was applied to cover the tear and polymerized with a 40-second application of xenon light. Retinal adhesion strength was tested by forcefully squirting balanced salt solution (BSS) onto the retinal tear. Polyethylene glycol-based synthetic sealant was soaked in the BSS, incubated at 37°C, and the pH measured periodically over 72 hours. In an in vivo study, PEG sealant was injected into the vitreous cavity of the left eyes of rabbits. Ophthalmologic examinations were performed and bilateral ERGs were recorded simultaneously before and 28 days after injection. The eyes were enucleated for histological evaluation. RESULTS: Adhesion of PEG sealant to the retina was good in BSS. A forceful squirt of BSS onto the retinal tear covered with PEG sealant did not detach the retina; the retinal tear without PEG sealant detached immediately. The pH of the BSS containing PEG sealant was between 7.2 and 8.2. No inflammatory reaction was observed in the eyes throughout 28 days of follow-up. The ERGs recorded before and after injection showed typical patterns. Histological examinations did not reveal any abnormality or inflammation. CONCLUSIONS: Polyethylene glycol-based synthetic sealant appeared to effectively seal retinal breaks and was not toxic to the eye.

Hoyek S, Wang M, Berrocal AM, Wong A, Place EM, Mason-Suares H, Lin AE, Mukai S, Patel NA. Combined X-linked familial exudative vitreoretinopathy and retinopathy of prematurity phenotype in an infant with mosaic turner syndrome with ring X chromosome. Ophthalmic Genet 2022;:1-6.Abstract
BACKGROUND: Retinopathy of prematurity (ROP) and familial exudative vitreoretinopathy (FEVR) are two distinct pathologies of retinal angiogenesis with overlapping clinical features. METHODS: Examination, multimodal imaging, and genetic testing were used to guide diagnosis and treatment. RESULTS: We report a combined phenotype of X-linked FEVR and ROP in a 4-month-old girl with mosaic Turner syndrome with ring X chromosome born at 26 weeks gestational age. She was initially diagnosed with atypical ROP with a vitreous band causing a localized traction retinal detachment, inferotemporal to the macula in the right eye, vessels to posterior zone 2 with no clear ridge temporally in the left eye, and fluorescein leakage in both eyes. Due to the suspicion of concurrent FEVR, genetic testing using a vitreoretinopathy panel was performed which revealed a mosaic Turner syndrome associated with 45,X/46,X,r(X), subsequently confirmed by chromosome analysis. The deleted region in the ring X chromosome included the NDP and RS1 genes. The patient was treated with laser photocoagulation of the peripheral avascular retina and sub-Tenon's triamcinolone injection in both eyes, intravitreal injection of bevacizumab in the left eye, and pars plicata vitrectomy in the right eye. CONCLUSIONS: In premature neonates with atypical ROP, a clinical suspicion of concurrent FEVR or similar vasculopathy is important and genetic testing may elucidate a genetic etiology, which could influence management and prognosis. Turner syndrome can be connected with co-occurring Mendelian gene disorders, particularly in individuals with mosaicism. The concurrence of FEVR and ROP appears to result in atypical and possibly more severe phenotypes.
Huang S, Liu C-H, Wang Z, Fu Z, Britton WR, Blomfield AK, Kamenecka TM, Dunaief JL, Solt LA, Chen J. REV-ERBα regulates age-related and oxidative stress-induced degeneration in retinal pigment epithelium via NRF2. Redox Biol 2022;51:102261.Abstract
Retinal pigment epithelium (RPE) dysfunction and atrophy occur in dry age-related macular degeneration (AMD), often leading to photoreceptor degeneration and vision loss. Accumulated oxidative stress during aging contributes to RPE dysfunction and degeneration. Here we show that the nuclear receptor REV-ERBα, a redox sensitive transcription factor, protects RPE from age-related degeneration and oxidative stress-induced damage. Genetic deficiency of REV-ERBα leads to accumulated oxidative stress, dysfunction and degeneration of RPE, and AMD-like ocular pathologies in aging mice. Loss of REV-ERBα exacerbates chemical-induced RPE damage, and pharmacological activation of REV-ERBα protects RPE from oxidative damage both in vivo and in vitro. REV-ERBα directly regulates transcription of nuclear factor erythroid 2-related factor 2 (NRF2) and its downstream antioxidant enzymes superoxide dismutase 1 (SOD1) and catalase to counter oxidative damage. Moreover, aged mice with RPE specific knockout of REV-ERBα also exhibit accumulated oxidative stress and fundus and RPE pathologies. Together, our results suggest that REV-ERBα is a novel intrinsic protector of the RPE against age-dependent oxidative stress and a new molecular target for developing potential therapies to treat age-related retinal degeneration.
Huang X, Sun J, Majoor J, Vermeer KA, Lemij H, Elze T, Wang M, Boland MV, Pasquale LR, Mohammadzadeh V, Nouri-Mahdavi K, Johnson C, Yousefi S. Estimating the Severity of Visual Field Damage From Retinal Nerve Fiber Layer Thickness Measurements With Artificial Intelligence. Transl Vis Sci Technol 2021;10(9):16.Abstract
Purpose: The purpose of this study was to assess the accuracy of artificial neural networks (ANN) in estimating the severity of mean deviation (MD) from peripapillary retinal nerve fiber layer (RNFL) thickness measurements derived from optical coherence tomography (OCT). Methods: Models were trained using 1796 pairs of visual field and OCT measurements from 1796 eyes to estimate visual field MD from RNFL data. Multivariable linear regression, random forest regressor, support vector regressor, and 1D convolutional neural network (CNN) models with sectoral RNFL thickness measurements were examined. Three independent subsets consisting of 698, 256, and 691 pairs of visual field and OCT measurements were used to validate the models. Estimation errors were visualized to assess model performance subjectively. Mean absolute error (MAE), root mean square error (RMSE), median absolute error, Pearson correlation, and R-squared metrics were used to assess model performance objectively. Results: The MAE and RMSE of the ANN model based on the testing dataset were 4.0 dB (95% confidence interval = 3.8-4.2) and 5.2 dB (95% confidence interval = 5.1-5.4), respectively. The ranges of MAE and RMSE of the ANN model on independent datasets were 3.3-5.9 dB and 4.4-8.4 dB, respectively. Conclusions: The proposed ANN model estimated MD from RNFL measurements better than multivariable linear regression model, random forest, support vector regressor, and 1-D CNN models. The model was generalizable to independent data from different centers and varying races. Translational Relevance: Successful development of ANN models may assist clinicians in assessing visual function in glaucoma based on objective OCT measures with less dependence on subjective visual field tests.
Huang X, Zhou G, Wu W, Ma G, D'Amore PA, Mukai S, Lei H. Editing VEGFR2 Blocks VEGF-Induced Activation of Akt and Tube Formation. Invest Ophthalmol Vis Sci 2017;58(2):1228-1236.Abstract

Purpose: Vascular endothelial growth factor receptor 2 (VEGFR2) plays a key role in VEGF-induced angiogenesis. The goal of this project was to test the hypothesis that editing genomic VEGFR2 loci using the technology of clustered regularly interspaced palindromic repeats (CRISPR)-associated DNA endonuclease (Cas)9 in Streptococcus pyogenes (SpCas9) was able to block VEGF-induced activation of Akt and tube formation. Methods: Four 20 nucleotides for synthesizing single-guide RNAs based on human genomic VEGFR2 exon 3 loci were selected and cloned into a lentiCRISPR v2 vector, respectively. The DNA fragments from the genomic VEGFR2 exon 3 of transduced primary human retinal microvascular endothelial cells (HRECs) were analyzed by Sanger DNA sequencing, surveyor nuclease assay, and next-generation sequencing (NGS). In the transduced cells, expression of VEGFR2 and VEGF-stimulated signaling events (e.g., Akt phosphorylation) were determined by Western blot analyses; VEGF-induced cellular responses (proliferation, migration, and tube formation) were examined. Results: In the VEGFR2-sgRNA/SpCas9-transduced HRECs, Sanger DNA sequencing indicated that there were mutations, and NGS demonstrated that there were 83.57% insertion and deletions in the genomic VEGFR2 locus; expression of VEGFR2 was depleted in the VEGFR2-sgRNA/SpCas9-transduced HRECs. In addition, there were lower levels of Akt phosphorylation in HRECs with VEGFR2-sgRNA/SpCas9 than those with LacZ-sgRNA/SpCas9, and there was less VEGF-stimulated Akt activation, proliferation, migration, or tube formation in the VEGFR2-depleted HRECs than those treated with aflibercept or ranibizumab. Conclusions: The CRISPR-SpCas9 technology is a potential novel approach to prevention of pathologic angiogenesis.

Huang R, Baranov P, Lai K, Zhang X, Ge J, Young MJ. Functional and morphological analysis of the subretinal injection of human retinal progenitor cells under Cyclosporin A treatment. Mol Vis 2014;20:1271-80.Abstract
PURPOSE: The purpose of this study is to evaluate the functional and morphological changes in subretinal xenografts of human retinal progenitor cells (hRPCs) in B6 mice treated with Cyclosporin A (CsA; 210 mg/l in drinking water). METHODS: The hRPCs from human fetal eyes were isolated and expanded for transplantation. These cells, with green fluorescent protein (GFP) at 11 passages, were transplanted into the subretinal space in B6 mice. A combination of invasive and noninvasive approaches was used to analyze the structural and functional consequences of the subretinal injection of the hRPCs. The process of change was monitored using spectral domain optical coherence tomography (SDOCT), histology, and electroretinography (ERG) at 3 days, 1 week, and 3 weeks after transplantation. Cell counts were used to evaluate the survival rate with a confocal microscope. ERGs were performed to evaluate the physiologic changes, and the structural changes were evaluated using SDOCT and histological examination. RESULTS: The results of the histological examination showed that the hRPCs gained a better survival rate in the mice treated with CsA. The SDOCT showed that the bleb size of the retinal detachment was significantly decreased, and the retinal reattachment was nearly complete by 3 weeks. The ERG response amplitudes in the CsA group were less decreased after the injection, when compared with the control group, in the dark-adapted and light-adapted conditions. However, the cone-mediated function in both groups was less affected by the transplantation after 3 weeks than the rod-mediated function. CONCLUSIONS: Although significant functional and structural recovery was observed after the subretinal injection of the hRPCs, the effectiveness of CsA in xenotransplantation may be a novel and potential approach for increasing retinal progenitor cell survival.
Huckfeldt RM, Grigorian F, Place E, Comander JI, Vavvas D, Young LH, Yang P, Shurygina M, Pierce EA, Pennesi ME. Biallelic -associated retinal dystrophies: Expanding the mutational and clinical spectrum. Mol Vis 2020;26:423-433.Abstract
Purpose: To evaluate the phenotypic spectrum of autosomal recessive associated retinal dystrophies and assess genotypic associations. Methods: A retrospective multicenter study was performed of patients with biallelic -associated retinal dystrophies. Data including presenting symptoms and age, visual acuity, kinetic perimetry, full field electroretinogram, fundus examination, multimodal retinal imaging, and genotype were evaluated. Results: Nineteen eligible patients from 17 families were identified and ranged in age from 10 to 56 years at the most recent evaluation. Ten of the 21 unique variants identified were novel, and mutations within exon 2 accounted for nearly half of alleles across the cohort. Patients had clinical diagnoses of retinitis pigmentosa (13), cone-rod dystrophy (3), Leber congenital amaurosis (1), early-onset severe retinal dystrophy (1), and macular dystrophy (1). Macular atrophy was a common feature across the cohort. Symptom onset occurred between 4 and 30 years of age (mean 14.9 years, median 13 years), but there were clusters of onset age that correlated with the effects of mutations at a protein level. Patients with later-onset disease, including retinitis pigmentosa, had at least one missense variant in an exon 2 DCX domain. Conclusions: Biallelic mutations cause a broad spectrum of retinal disease. Exon 2 missense mutations are a significant contributor to disease and can be associated with a considerably later onset of retinitis pigmentosa than that typically associated with biallelic mutations.
Hunter DG. Improving Access-but Not Outcomes-With Iris Optical Coherence Tomography Angiography. JAMA Ophthalmol 2018;136(9):1045-1046.
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