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Gong Y, Fu Z, Edin ML, Liu C-H, Wang Z, Shao Z, Fredrick TW, Saba NJ, Morss PC, Burnim SB, Meng SS, Lih FB, Stephen Lee KS, Moran EP, SanGiovanni JP, Hellström A, Hammock BD, Zeldin DC, Smith LEH. Cytochrome P450 Oxidase 2C Inhibition Adds to ω-3 Long-Chain Polyunsaturated Fatty Acids Protection Against Retinal and Choroidal Neovascularization. Arterioscler Thromb Vasc Biol 2016;36(9):1919-27.Abstract

OBJECTIVE: Pathological ocular neovascularization is a major cause of blindness. Increased dietary intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) reduces retinal neovascularization and choroidal neovascularization (CNV), but ω-3 LCPUFA metabolites of a major metabolizing pathway, cytochrome P450 oxidase (CYP) 2C, promote ocular pathological angiogenesis. We hypothesized that inhibition of CYP2C activity will add to the protective effects of ω-3 LCPUFA on neovascular eye diseases. APPROACH AND RESULTS: The mouse models of oxygen-induced retinopathy and laser-induced CNV were used to investigate pathological angiogenesis in the retina and choroid, respectively. The plasma levels of ω-3 LCPUFA metabolites of CYP2C were determined by mass spectroscopy. Aortic ring and choroidal explant sprouting assays were used to investigate the effects of CYP2C inhibition and ω-3 LCPUFA-derived CYP2C metabolic products on angiogenesis ex vivo. We found that inhibition of CYP2C activity by montelukast added to the protective effects of ω-3 LCPUFA on retinal neovascularization and CNV by 30% and 20%, respectively. In CYP2C8-overexpressing mice fed a ω-3 LCPUFA diet, montelukast suppressed retinal neovascularization and CNV by 36% and 39% and reduced the plasma levels of CYP2C8 products. Soluble epoxide hydrolase inhibition, which blocks breakdown and inactivation of CYP2C ω-3 LCPUFA-derived active metabolites, increased oxygen-induced retinopathy and CNV in vivo. Exposure to selected ω-3 LCPUFA metabolites of CYP2C significantly reversed the suppression of both angiogenesis ex vivo and endothelial cell functions in vitro by the CYP2C inhibitor montelukast. CONCLUSIONS: Inhibition of CYP2C activity adds to the protective effects of ω-3 LCPUFA on pathological retinal neovascularization and CNV.

Wu N, Wang Y, Yang L, Cho K-S. Signaling Networks of Retinal Ganglion Cell Formation and the Potential Application of Stem Cell-Based Therapy in Retinal Degenerative Diseases. Hum Gene Ther 2016;27(8):609-620.Abstract

Retinal degenerative diseases such as age-related macular degeneration, retinitis pigmentosa, and glaucoma result in permanent loss of retinal neurons and vision. Stem cell therapy could be a novel treatment strategy to restore visual function. In an ideal situation, a homogenous population of stem cell-derived retinal neurons with high purity is used for replacement therapy. Thus, it is crucial to elucidate the molecular mechanisms that regulate the development of retinal progenitor cells and subsequent generation of specific retinal neurons. Here, recent findings concerning the intrinsic and extrinsic factors that regulate retinal progenitor cell maintenance and differentiation are summarized, especially transcriptional factors and extrinsic signals. Understanding these mechanisms is indispensable because they have potential clinical applications, chiefly the generation of specific retinal cells such as retinal ganglion cells to treat glaucoma and other optic neuropathy diseases.

Duan Y, Ma G, Huang X, D'Amore PA, Zhang F, Lei H. The Clustered, Regularly Interspaced, Short Palindromic Repeats-associated Endonuclease 9 (CRISPR/Cas9)-created MDM2 T309G Mutation Enhances Vitreous-induced Expression of MDM2 and Proliferation and Survival of Cells. J Biol Chem 2016;291(31):16339-47.Abstract

The G309 allele of SNPs in the mouse double minute (MDM2) promoter locus is associated with a higher risk of cancer and proliferative vitreoretinopathy (PVR), but whether SNP G309 contributes to the pathogenesis of PVR is to date unknown. The clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease (Cas) 9 from Streptococcus pyogenes (SpCas9) can be harnessed to manipulate a single or multiple nucleotides in mammalian cells. Here we delivered SpCas9 and guide RNAs using dual adeno-associated virus-derived vectors to target the MDM2 genomic locus together with a homologous repair template for creating the mutation of MDM2 T309G in human primary retinal pigment epithelial (hPRPE) cells whose genotype is MDM2 T309T. The next-generation sequencing results indicated that there was 42.51% MDM2 G309 in the edited hPRPE cells using adeno-associated viral CRISPR/Cas9. Our data showed that vitreous induced an increase in MDM2 and subsequent attenuation of p53 expression in MDM2 T309G hPRPE cells. Furthermore, our experimental results demonstrated that MDM2 T309G in hPRPE cells enhanced vitreous-induced cell proliferation and survival, suggesting that this SNP contributes to the pathogenesis of PVR.

Tian B, Maidana DE, Dib B, Miller JB, Bouzika P, Miller JW, Vavvas DG, Lin H. miR-17-3p Exacerbates Oxidative Damage in Human Retinal Pigment Epithelial Cells. PLoS One 2016;11(8):e0160887.Abstract

Oxidative stress has been shown to contribute to the development of age-related macular degeneration (AMD). MicroRNAs (miRNA) are small non-coding RNA molecules that function in RNA silencing and post-transcriptional regulation of gene expression. We showed miR-17-3p to be elevated in macular RPE cells from AMD patients and in ARPE-19 cells under oxidative stress. Transfection of miR-17-3p mimic in ARPE-19 induced cell death and exacerbated oxidative lethality that was alleviated by miR-17-3p inhibitor. The expression of antioxidant enzymes manganese superoxide dismutase (MnSOD) and thioredoxin reductase-2 (TrxR2) were suppressed by miR-17-3p mimic and reversed by miR-17-3p inhibitor. These results suggest miR-17-3p aggravates oxidative damage-induced cell death in human RPE cells, while miR-17-3p inhibitor acts as a potential protector against oxidative stress by regulating the expression of antioxidant enzymes.

Crnej A, Kheirkhah A, Ren A, Mullins A, Lavric A, Suri K, Hamrah P, Dana R. Patients' Perspectives on Their Dry Eye Disease. Ocul Surf 2016;14(4):440-446.Abstract

PURPOSE: Although it has been known that patients' perspectives on their disease can significantly affect their level of functional disability as well as disease outcome, limited data are available on patients' perceptions of their dry eye disease (DED). The aim of this questionnaire-based study was to evaluate patients' perspectives on their DED. METHODS: This cross-sectional study included 91 patients with DED. In addition to clinical evaluation, all patients completed a questionnaire to evaluate their perspectives on their DED. This included their satisfaction with understanding DED, their opinion on the easiness of following doctors' advice, their opinion on the effectiveness of the treatment, their satisfaction with the eye care, and their general outlook on DED. RESULTS: This study included 75 (82%) women and 16 men (18%) with a mean age of 57 ± 14 years who had been treated for DED for 5.2 ± 5.4 years. 93% of the patients were satisfied with their understanding of DED, and 76% found it easy to follow their doctors' advice for DED management. Furthermore, 95% thought that the DED treatment had been helpful and 95% were satisfied with their eye care for DED. Forty-eight percent expressed optimism regarding the long-term prospects of their DED. CONCLUSIONS: Although the majority of DED patients have positive perspectives on their disease, close to half report a lack of optimism regarding the long-term outlook for their condition.

Semo M'ayan, Haamedi N, Stevanato L, Carter D, Brooke G, Young M, Coffey P, Sinden J, Patel S, Vugler A. Efficacy and Safety of Human Retinal Progenitor Cells. Transl Vis Sci Technol 2016;5(4):6.Abstract

PURPOSE: We assessed the long-term efficacy and safety of human retinal progenitor cells (hRPC) using established rodent models. METHODS: Efficacy of hRPC was tested initially in Royal College of Surgeons (RCS) dystrophic rats immunosuppressed with cyclosporine/dexamethasone. Due to adverse effects of dexamethasone, this drug was omitted from a subsequent dose-ranging study, where different hRPC doses were tested for their ability to preserve visual function (measured by optokinetic head tracking) and retinal structure in RCS rats at 3 to 6 months after grafting. Safety of hRPC was assessed by subretinal transplantation into wild type (WT) rats and NIH-III nude mice, with analysis at 3 to 6 and 9 months after grafting, respectively. RESULTS: The optimal dose of hRPC for preserving visual function/retinal structure in dystrophic rats was 50,000 to 100,000 cells. Human retinal progenitor cells integrated/survived in dystrophic and WT rat retina up to 6 months after grafting and expressed nestin, vimentin, GFAP, and βIII tubulin. Vision and retinal structure remained normal in WT rats injected with hRPC and there was no evidence of tumors. A comparison between dexamethasone-treated and untreated dystrophic rats at 3 months after grafting revealed an unexpected reduction in the baseline visual acuity of dexamethasone-treated animals. CONCLUSIONS: Human retinal progenitor cells appear safe and efficacious in the preclinical models used here. TRANSLATIONAL RELEVANCE: Human retinal progenitor cells could be deployed during early stages of retinal degeneration or in regions of intact retina, without adverse effects on visual function. The ability of dexamethasone to reduce baseline visual acuity in RCS dystrophic rats has important implications for the interpretation of preclinical and clinical cell transplant studies.

Modjtahedi BS, van Zyl T, Pandya HK, Leonard RE, Eliott D. Endophthalmitis After Intravitreal Injections in Patients With Self-reported Iodine Allergy. Am J Ophthalmol 2016;170:68-74.Abstract

PURPOSE: To present cases of endophthalmitis following intravitreal injections where povidone-iodine (PI) was not used as part of the surgical preparation. DESIGN: Retrospective case series. METHODS: All cases of presumed injection-related endophthalmitis presenting to the Massachusetts Eye and Ear Infirmary between June 2008 and November 2014 and Dean McGee Eye Institute between January 2010 and January 2015 were identified. Patients who did not receive PI preparation owing to documented self-reported allergy to iodine, iodine-containing contrast material, or shellfish were identified and their injection histories and clinical courses reviewed. RESULTS: The combined rate of postinjection endophthalmitis at these 2 centers was 0.019%. Among 42 patients with postinjection endophthalmitis, 5 (11.9%) did not receive PI prophylaxis. The mean number of intravitreal injections without PI before the development of endophthalmitis was 10.6 with a 9.4% rate of endophthalmitis (5 cases per 53 injections). All patients underwent tap-and-inject procedures with vancomycin 1 mg and ceftazidime 2 mg. Two patients did not receive PI at the time of tap and inject; 1 of these patients required subsequent pars plana vitrectomy for worsening clinical course. Cultures were positive in 4 of 5 cases; all positive cultures grew coagulase-negative Staphylococcus. All patients who received subsequent intravitreal injections received PI prophylaxis without allergic reactions, thus demonstrating a lack of true PI allergy. CONCLUSIONS: Avoiding PI owing to self-reported iodine "allergy" risks substantial ocular morbidity. Allergy testing can be pursued per patient request or in rare cases of suspected true PI allergy; however, in cases where delayed treatment would adversely affect visual outcome, the clinician should feel confident that minimal allergic risk exists.

Kim CB, D'Amore PA, Connor KM. Revisiting the mouse model of oxygen-induced retinopathy. Eye Brain 2016;8:67-79.Abstract

Abnormal blood vessel growth in the retina is a hallmark of many retinal diseases, such as retinopathy of prematurity (ROP), proliferative diabetic retinopathy, and the wet form of age-related macular degeneration. In particular, ROP has been an important health concern for physicians since the advent of routine supplemental oxygen therapy for premature neonates more than 70 years ago. Since then, researchers have explored several animal models to better understand ROP and retinal vascular development. Of these models, the mouse model of oxygen-induced retinopathy (OIR) has become the most widely used, and has played a pivotal role in our understanding of retinal angiogenesis and ocular immunology, as well as in the development of groundbreaking therapeutics such as anti-vascular endothelial growth factor injections for wet age-related macular degeneration. Numerous refinements to the model have been made since its inception in the 1950s, and technological advancements have expanded the use of the model across multiple scientific fields. In this review, we explore the historical developments that have led to the mouse OIR model utilized today, essential concepts of OIR, limitations of the model, and a representative selection of key findings from OIR, with particular emphasis on current research progress.

Jain R, Sharma N, Basu S, Iyer G, Ueta M, Sotozono C, Kannabiran C, Rathi VM, Gupta N, Kinoshita S, Gomes JAP, Chodosh J, Sangwan VS. Stevens-Johnson syndrome: The role of an ophthalmologist. Surv Ophthalmol 2016;61(4):369-99.Abstract

Stevens-Johnson syndrome (SJS) is an acute blistering disease of the skin and mucous membranes. Acute SJS leads to the acute inflammation of the ocular surface and chronic conjunctivitis. If not properly treated, it causes chronic cicatricial conjunctivitis and cicatricial lid margin abnormalities. Persistent inflammation and ulceration of the ocular surface with cicatricial complications of the lids leads to chronic ocular sequelae, ocular surface damage, and corneal scarring. The destruction of the glands that secrete the tear film leads to a severe form of dry eye that makes the management of chronic SJS difficult. The option that is routinely used for corneal visual rehabilitation, keratoplasty, is best avoided in such cases. We describe the management strategies that are most effective during the acute and chronic stages of SJS. Although treatments for acute SJS involve immunosuppressive and immunomodulatory therapies, amniotic membrane transplantation is also useful. The options for visual rehabilitation in patients with chronic SJS are undergoing radical change. We describe the existing literature regarding the management of SJS and highlight recent advances in the management of this disorder.

Gómez-Laberge C, Smolyanskaya A, Nassi JJ, Kreiman G, Born RT. Bottom-Up and Top-Down Input Augment the Variability of Cortical Neurons. Neuron 2016;91(3):540-7.Abstract

Neurons in the cerebral cortex respond inconsistently to a repeated sensory stimulus, yet they underlie our stable sensory experiences. Although the nature of this variability is unknown, its ubiquity has encouraged the general view that each cell produces random spike patterns that noisily represent its response rate. In contrast, here we show that reversibly inactivating distant sources of either bottom-up or top-down input to cortical visual areas in the alert primate reduces both the spike train irregularity and the trial-to-trial variability of single neurons. A simple model in which a fraction of the pre-synaptic input is silenced can reproduce this reduction in variability, provided that there exist temporal correlations primarily within, but not between, excitatory and inhibitory input pools. A large component of the variability of cortical neurons may therefore arise from synchronous input produced by signals arriving from multiple sources.

Shieh E, Lee R, Que C, Srinivasan V, Guo R, DeLuna R, Pandit S, Simavli H, Seevaratnam R, Tsikata E, de Boer J, Chen TC. Diagnostic Performance of a Novel Three-Dimensional Neuroretinal Rim Parameter for Glaucoma Using High-Density Volume Scans. Am J Ophthalmol 2016;169:168-78.Abstract

PURPOSE: To evaluate the diagnostic performance of a 3-dimensional (3D) neuroretinal rim parameter, the minimum distance band (MDB), using optical coherence tomography (OCT) high-density volume scans for open-angle glaucoma. DESIGN: Reliability analysis. METHODS: setting: Institutional. STUDY POPULATION: Total of 163 patients (105 glaucoma and 58 healthy subjects). OBSERVATION PROCEDURES: One eye of each patient was included. MDB and retinal nerve fiber layer (RNFL) thickness values were determined for 4 quadrants and 4 sectors using a spectral-domain OCT device. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUROC) values, sensitivities, specificities, and positive and negative predictive values. RESULTS: The best AUROC values of 3D MDB thickness for glaucoma and early glaucoma were for the overall globe (0.969, 0.952), followed by the inferior quadrant (0.966, 0.949) and inferior-temporal sector (0.966, 0.944), and then followed by the superior-temporal sector (0.964, 0.932) and superior quadrant (0.962, 0.924). All 3D MDB thickness AUROC values were higher than those of 2D RNFL thickness. Pairwise comparisons showed that the diagnostic performance of the 3D MDB parameter was significantly better than 2D RNFL thickness only for the nasal quadrant and inferior-nasal and superior-nasal sectors (P = .023-.049). Combining 3D MDB with 2D RNFL parameters provided significantly better diagnostic performance (AUROC 0.984) than most single MDB parameters and all single RNFL parameters. CONCLUSIONS: Compared with the 2D RNFL thickness parameter, the 3D MDB neuroretinal rim thickness parameter had uniformly equal or better diagnostic performance for glaucoma in all regions and was significantly better in the nasal region.

Ebrahimiadib N, Modjtahedi BS, Roohipoor R, Anesi SD, Foster SC. Successful Treatment Strategies in Granulomatosis With Polyangiitis-Associated Peripheral Ulcerative Keratitis. Cornea 2016;35(11):1459-1465.Abstract

PURPOSE: Management of granulomatosis with polyangiitis (GPA)-associated peripheral ulcerative keratitis (PUK) is challenging and lacks definite guidelines. We aimed to summarize our treatment and outcome experience with patients with GPA-PUK. METHODS: The Massachusetts Eye Research and Surgery Institution patient database was searched from 2005 to 2015 to identify patients with diagnosis of PUK who suffered from GPA. Individual patient histories were examined, and treatment strategies and outcomes were summarized. RESULTS: There were 16 patients who started treatment with a mean duration follow-up of 64 months (range: 12-110 mo). Rituximab and cyclophosphamide, either alone or in combination with other agents, were the most successful agents in controlling inflammation. Rituximab was administered in 11 patients with remission being achieved in all. Cyclophosphamide successfully controlled inflammation in 50% (5/10). Two of the patients (2/5, 40%) who had achieved initial control on cyclophosphamide had flares of their PUK. Two of 11 (18%) patients on rituximab had flares of scleritis and orbital inflammation but not PUK. Two patients, one in each treatment group, stopped treatment after achieving remission after 6 months of therapy but suffered disease recurrence within 2 months of treatment cessation. CONCLUSIONS: Rituximab achieved a high rate of disease control in PUK patients with GPA and is the preferred agent in halting disease progression.

Bennett J, Wellman J, Marshall KA, McCague S, Ashtari M, DiStefano-Pappas J, Elci OU, Chung DC, Sun J, Wright FJ, Cross DR, Aravand P, Cyckowski LL, Bennicelli JL, Mingozzi F, Auricchio A, Pierce EA, Ruggiero J, Leroy BP, Simonelli F, High KA, Maguire AM. Safety and durability of effect of contralateral-eye administration of AAV2 gene therapy in patients with childhood-onset blindness caused by RPE65 mutations: a follow-on phase 1 trial. Lancet 2016;Abstract

BACKGROUND: Safety and efficacy have been shown in a phase 1 dose-escalation study involving a unilateral subretinal injection of a recombinant adeno-associated virus (AAV) vector containing the RPE65 gene (AAV2-hRPE65v2) in individuals with inherited retinal dystrophy caused by RPE65 mutations. This finding, along with the bilateral nature of the disease and intended use in treatment, prompted us to determine the safety of administration of AAV2-hRPE65v2 to the contralateral eye in patients enrolled in the phase 1 study. METHODS: In this follow-on phase 1 trial, one dose of AAV2-hRPE65v2 (1·5 × 10(11) vector genomes) in a total volume of 300 μL was subretinally injected into the contralateral, previously uninjected, eyes of 11 children and adults (aged 11-46 years at second administration) with inherited retinal dystrophy caused by RPE65 mutations, 1·71-4·58 years after the initial subretinal injection. We assessed safety, immune response, retinal and visual function, functional vision, and activation of the visual cortex from baseline until 3 year follow-up, with observations ongoing. This study is registered with ClinicalTrials.gov, number NCT01208389. FINDINGS: No adverse events related to the AAV were reported, and those related to the procedure were mostly mild (dellen formation in three patients and cataracts in two). One patient developed bacterial endophthalmitis and was excluded from analyses. We noted improvements in efficacy outcomes in most patients without significant immunogenicity. Compared with baseline, pooled analysis of ten participants showed improvements in mean mobility and full-field light sensitivity in the injected eye by day 30 that persisted to year 3 (mobility p=0·0003, white light full-field sensitivity p<0·0001), but no significant change was seen in the previously injected eyes over the same time period (mobility p=0·7398, white light full-field sensitivity p=0·6709). Changes in visual acuity from baseline to year 3 were not significant in pooled analysis in the second eyes or the previously injected eyes (p>0·49 for all time-points compared with baseline). INTERPRETATION: To our knowledge, AAV2-hRPE65v2 is the first successful gene therapy administered to the contralateral eye. The results highlight the use of several outcome measures and help to delineate the variables that contribute to maximal benefit from gene augmentation therapy in this disease. FUNDING: Center for Cellular and Molecular Therapeutics at The Children's Hospital of Philadelphia, Spark Therapeutics, US National Institutes of Health, Foundation Fighting Blindness, Institute for Translational Medicine and Therapeutics, Research to Prevent Blindness, Center for Advanced Retinal and Ocular Therapeutics, Mackall Foundation Trust, F M Kirby Foundation, and The Research Foundation-Flanders.

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