Proliferative retinopathic diseases often progress in 2 phases: initial regression of retinal vasculature (phase 1) followed by subsequent neovascularization (NV) (phase 2). The immune system has been shown to aid in vascular pruning in such retinopathies; however, little is known about the role of the alternative complement pathway in the initial vascular regression phase. Using a mouse model of oxygen-induced retinopathy (OIR), we observed that alternative complement pathway-deficient mice (Fb(-/-)) exhibited a mild decrease in vascular loss at postnatal day (P)8 compared with age- and strain-matched controls (P = 0.035). Laser capture microdissection was used to isolate the retinal blood vessels. Expression of the complement inhibitors Cd55 and Cd59 was significantly decreased in blood vessels isolated from hyperoxic retinas compared with those from normoxic control mice. Vegf expression was measured at P8 and found to be significantly lower in OIR mice than in normoxic control mice (P = 0.0048). Further examination of specific Vegf isoform expression revealed a significant decrease in Vegf120 (P = 0.00032) and Vegf188 (P = 0.0092). In conjunction with the major modulating effects of Vegf during early retinal vascular development, our data suggest a modest involvement of the alternative complement pathway in targeting vessels for regression in the initial vaso-obliteration stage of OIR.-Kim, C., Smith, K. E., Castillejos, A., Diaz-Aguilar, D., Saint-Geniez, M., Connor, K. M. The alternative complement pathway aids in vascular regression during the early stages of a murine model of proliferative retinopathy.

Tissue decellularization strategies have enabled engineering of scaffolds that preserve native extracellular matrix (ECM) structure and composition. In this study, we developed decellularized retina (decell-retina) thin films. We hypothesized that these films, mimicking the retina niche, would promote human retinal progenitor cell (hRPC) attachment, proliferation and differentiation. Retinas isolated from bovine eyes were decellularized using 1% w/v sodium dodecyl sulfate (SDS) and pepsin digested. The resulting decell-retina was biochemically assayed for composition and cast dried to develop thin films. Attachment, viability, morphology, proliferation and gene expression of hRPC cultured on the films were studied in vitro. Biochemical analyses of decell-retina compared to native retina indicated the bulk of DNA (94%) was removed, while the majority of sulfated GAGs (55%), collagen (83%), hyaluronic acid (87%), and key growth factors were retained. The decell-retina films supported hRPC attachment and growth, with cell number increasing 1.5-fold over a week. RT-PCR analysis revealed hRPC expression of rhodopsin, rod outer membrane, neural retina-specific leucine zipper neural and cone-rod homeobox gene on decell-retina films, indicating photoreceptor development. In conclusion, novel decell-retina films show promise as potential substrates for culture and/or transplantation of retinal progenitor cells to treat retinal degenerative disorders.

Mucolipidosis IV is a debilitating developmental lysosomal storage disorder characterized by severe neuromotor retardation and progressive loss of vision, leading to blindness by the second decade of life. Mucolipidosis IV is caused by loss-of-function mutations in the MCOLN1 gene, which encodes the transient receptor potential channel protein mucolipin-1. Ophthalmic pathology in patients includes corneal haze and progressive retinal and optic nerve atrophy. Herein, we report ocular pathology in Mcoln1(-/-) mouse, a good phenotypic model of the disease. Early, but non-progressive, thinning of the photoreceptor layer, reduced levels of rhodopsin, disrupted rod outer segments, and widespread accumulation of the typical storage inclusion bodies were the major histological findings in the Mcoln1(-/-) retina. Electroretinograms showed significantly decreased functional response (scotopic a- and b-wave amplitudes) in the Mcoln1(-/-) mice. At the ultrastructural level, we observed formation of axonal spheroids and decreased density of axons in the optic nerve of the aged (6-month-old) Mcoln1(-/-) mice, which indicates progressive axonal degeneration. Our data suggest that mucolipin-1 plays a role in postnatal development of photoreceptors and provides a set of outcome measures that can be used for ocular therapy development for mucolipidosis IV.

Fas ligand (FasL) triggers apoptosis of Fas-positive cells, and previous reports described FasL-induced cell death of Fas-positive photoreceptors following a retinal detachment. However, as FasL exists in membrane-bound (mFasL) and soluble (sFasL) forms, and is expressed on resident microglia and infiltrating monocyte/macrophages, the current study examined the relative contribution of mFasL and sFasL to photoreceptor cell death after induction of experimental retinal detachment in wild-type, knockout (FasL-/-), and mFasL-only knock-in (ΔCS) mice. Retinal detachment in FasL-/- mice resulted in a significant reduction of photoreceptor cell death. In contrast, ΔCS mice displayed significantly more apoptotic photoreceptor cell death. Photoreceptor loss in ΔCS mice was inhibited by a subretinal injection of recombinant sFasL. Thus, Fas/FasL-triggered cell death accounts for a significant amount of photoreceptor cell loss following the retinal detachment. The function of FasL was dependent upon the form of FasL expressed: mFasL triggered photoreceptor cell death, whereas sFasL protected the retina, indicating that enzyme-mediated cleavage of FasL determines, in part, the extent of vision loss following the retinal detachment. Moreover, it also indicates that treatment with sFasL could significantly reduce photoreceptor cell loss in patients with retinal detachment.

The safety of laser pointers is a major public health issue since class I and II laser pointers are available worldwide and used as toys by children despite several reports cautioning such use. Here we present the first case of retinal injury caused by the laser beam of a toy laser pointer operated by a school boy and directed via the rear-view mirror of a bus into the eye of the driver. This case emphasises the great importance of cautious and appropriate use of low-energy laser pointers. Laser pointers of any class should not be made available to children because they are unlikely to understand the risks of such lasers when using them in play.

PURPOSE: To characterize the angiogenic and inflammatory vitreous biomarker profiles in a spectrum of ischemic retinopathies, including neovascular glaucoma. METHODS: This institutional review board-approved study retrospectively analyzed 80 undiluted vitreous samples obtained during pars vitrectomy. The specimens were frozen (-80°C) and sent for concentration analysis of 34 proteins by Bio-Plex Pro assays. Specimens were divided into four groups: patients undergoing epiretinal membrane (ERM) peeling and/or macular hole (MH) surgery with no history of diabetes (non-DM group), patients undergoing ERM peeling, and/or MH surgery with a history of diabetes (DM group), patients with proliferative diabetic retinopathy (PDR group), and patients with neovascular glaucoma (NVG group). Parametric and nonparametric analyses of demographics and cytokine levels were performed using SPSS. RESULTS: There were no significant differences in demographics among cohorts. Numerous proteins were significantly elevated between non-DM and DM (G-CSF, sCD40L, Endoglin, IL-6, placental growth factor [PlGF], VEGF-D), DM and PDR (leptin, IL-8, PlGF, VEGF-A), and PDR and NVG (G-CSF, leptin, TIE-2, sCD40L, EGF, HB-EGF, IL-6, IL-8, PlGF, TNF-α). Only PlGF was significantly elevated between each successive cohort. The most potent drivers of NVG were PlGF, VEGF-A, IL-6, and IL-8. CONCLUSIONS: While the role of angioproliferative growth factors is well documented in ischemic retinopathy, our study delineates the importance of inflammatory and previously underreported angiogenic proteins. It also demonstrates a significant incremental increase in certain factors with increasing levels of ischemia. Both of these findings may guide the development of future therapies for ischemic retinopathies.

Neurons and glial cells in the retina contribute to neovascularization, or the formation of abnormal new blood vessels, in proliferative retinopathy, a condition that can lead to vision loss or blindness. We identified a mechanism by which suppressor of cytokine signaling 3 (SOCS3) in neurons and glial cells prevents neovascularization. We found that Socs3 expression was increased in the retinal ganglion cell and inner nuclear layers after oxygen-induced retinopathy. Mice with Socs3 deficiency in neuronal and glial cells had substantially reduced vaso-obliterated retinal areas and increased pathological retinal neovascularization in response to oxygen-induced retinopathy, suggesting that loss of neuronal/glial SOCS3 increased both retinal vascular regrowth and pathological neovascularization. Furthermore, retinal expression of Vegfa (which encodes vascular endothelial growth factor A) was higher in these mice than in Socs3 flox/flox controls, indicating that neuronal and glial SOCS3 suppressed Vegfa expression during pathological conditions. Lack of neuronal and glial SOCS3 resulted in greater phosphorylation and activation of STAT3, which led to increased expression of its gene target Vegfa, and increased endothelial cell proliferation. In summary, SOCS3 in neurons and glial cells inhibited the STAT3-mediated secretion of VEGF from these cells, which suppresses endothelial cell activation, resulting in decreased endothelial cell proliferation and angiogenesis. These results suggest that neuronal and glial cell SOCS3 limits pathological retinal angiogenesis by suppressing VEGF signaling.

PURPOSE: To review presenting characteristics, clinical course, and long-term visual and anatomic outcomes of patients with traumatic macular holes at a tertiary referral center. DESIGN: Retrospective case series. METHODS: Twenty-eight consecutive patients with traumatic macular holes at a single tertiary referral center were reviewed. In addition to visual acuities and treatments throughout the clinical course, specific dimensions of the macular hole, including diameters, height, configuration, shape, and the presence of a cuff of fluid, were examined using spectral-domain optical coherence tomography (OCT). RESULTS: Twenty-eight patients were identified with a mean initial visual acuity (VA) of logMAR 1.3 (20/400) and a mean follow-up of 2.2 years. Eleven holes (39.3%) closed spontaneously in median 5.7 weeks. Eleven underwent vitrectomy with a median time to intervention of 35.1 weeks. Median time to surgery for the 5 eyes with successful hole closure was 11.0 weeks vs 56.3 weeks for the 6 eyes that failed to close (P = .02). VA improved in closed holes (P < .01), whether spontaneously (P < .01) or via vitrectomy (P = .04), but VA did not improve in holes that did not close (P = .22). There was no relation between initial OCT dimensions and final hole closure status, although there was a trend, which did not reach statistical significance, toward small dimensions for those that closed spontaneously. CONCLUSIONS: A fairly high spontaneous closure rate was observed, with a trend toward smaller OCT dimensions. We found no relationship between hole closure and the OCT characteristics of the hole. Surgical intervention was less successful at hole closure when elected after 3 months.

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.

Degeneration of photoreceptors is a primary cause of vision loss worldwide, making the underlying mechanisms surrounding photoreceptor cell death critical to developing new treatment strategies. Retinal detachment, characterized by the separation of photoreceptors from the underlying retinal pigment epithelium, is a sight-threatening event that can happen in a number of retinal diseases. The detached photoreceptors undergo apoptosis and programmed necrosis. Given that photoreceptors are nondividing cells, their loss leads to irreversible visual impairment even after successful retinal reattachment surgery. To better understand the underlying disease mechanisms, we analyzed innate immune system regulators in the vitreous of human patients with retinal detachment and correlated the results with findings in a mouse model of retinal detachment. We identified the alternative complement pathway as promoting early photoreceptor cell death during retinal detachment. Photoreceptors down-regulate membrane-bound inhibitors of complement, allowing for selective targeting by the alternative complement pathway. When photoreceptors in the detached retina were removed from the primary source of oxygen and nutrients (choroidal vascular bed), the retina became hypoxic, leading to an up-regulation of complement factor B, a key mediator of the alternative pathway. Inhibition of the alternative complement pathway in knockout mice or through pharmacological means ameliorated photoreceptor cell death during retinal detachment. Our current study begins to outline the mechanism by which the alternative complement pathway facilitates photoreceptor cell death in the damaged retina.

PURPOSE: To evaluate the efficacy of systemic infliximab for the induction of remission in patients with retinal vasculitis, inadequately responsive to other immunomodulatory therapy, based on fluorescein angiography grading for retinal vasculitis evaluation. METHODS: We analyzed 60 patients with retinal vasculitis, from the Massachusetts Eye Research and Surgery Institution in Cambridge, MA. Response to therapy was based on analysis of serial fluorescein angiography and fundus photography, including a baseline angiogram before initiation of infliximab. RESULTS: Sixty patients received infliximab therapy between July 2007 and July 2012 at Massachusetts Eye Research and Surgery Institution for a diagnosis of retinal vasculitis. All had previously showed a poor clinical response to other immunomodulatory regimens, or ceased therapy due to intolerable side effects. The initial dose of infliximab was 5 mg/kg in all patients and remained at this dose for the extent of treatment in 57 (95%) patients. At 6 months, 45 of 51 (88.23%) patients were maintaining remission with therapy, 5 (9.8%) were in partial remission, and 1 patient had failed. At 12 months, 39 of 39 (100%) patients were maintaining remission with therapy. CONCLUSION: Infliximab is effective for the treatment of recalcitrant noninfectious retinal vasculitis, refractory to conventional immunomodulatory therapy.

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.

BACKGROUND: Susac syndrome (SS) is a rare, presumed autoimmune condition characterized by the clinical triad of branch retinal artery occlusions (BRAOs), encephalopathy, and sensorineural hearing loss. The aim of this study was to evaluate clinical features, diagnostic results, treatment, and outcomes in SS. METHODS: Five patients with SS were referred to three tertiary care centers in Boston. The observation period across these patients was 7-57months. RESULTS: At initial presentation, none of the patients demonstrated the complete triad of BRAO, sensorineural hearing loss, and encephalopathy. The interval between symptom onset and diagnosis of SS was 4-30weeks. Brain MRI findings thought to be characteristic of SS (including callosal fluid-attenuated inversion recovery (FLAIR) hyperintense and T1 hypointense lesions) were frequently absent. Microinfarcts noted on diffusion-weighted imaging (DWI), BRAOs and vessel wall hyperfluorescence on fluorescein angiography (FA) were present in all cases in the acute encephalopathic phase. All patients treated with glucocorticoids and intravenous immunoglobulins (IVIg) alone experienced further clinical progression until additional immunosuppressive therapy was instituted. CONCLUSIONS: The rarity of SS, its incomplete and variable presentation, and the nonspecific imaging findings invariably led to delayed diagnosis. DWI and FA should be used to identify the acute microvascular injury and monitor treatment response. Immunomodulatory agents more potent than glucocorticoids and IVIg might be required to control the disease.

PURPOSE: To describe the anatomical and functional outcomes in a cohort of subjects undergoing vitrectomy for myopic foveoschisis, and to analyse the factors predicting foveal reattachment and visual improvement. METHODS: This retrospective case series evaluated case records and optical coherence tomography images 6 months after surgery. Multivariate linear and logistic regressions were performed to assess the factors predicting anatomical and visual improvement. RESULTS: In total, 55 eyes of 54 patients were analysed. The mean spherical equivalent refraction was -11.83±4.94D. Foveal detachment was present in 63.5% of eyes preoperatively and subjects with foveal detachment had 0.70 logMAR units (95% CI 0.02 to 1.39) poorer visual acuity than subjects without (p=0.046). The mean preoperative visual acuity was 0.84±0.59 logMAR units and the mean postoperative visual acuity was 0.64±0.64 logMAR units (mean difference 0.20±0.68 logMAR units (p=0.04)). The proportion of eyes with foveal detachment was significantly lower after surgery (12.5%; p<0.001). However, the proportion of eyes with ellipsoid zone disruption was significantly higher after surgery (59.6% vs 34.0%; p<0.001). In multivariate analyses, the preoperative central foveal thickness significantly predicted postoperative visual improvement by two or more lines (OR 1.004 (95% CI 1.000 to 1.007), per μm increase; p=0.049). The presence of ellipsoid zone disruption preoperatively was associated with 0.96 logMAR (95% CI 0.2 to 1.72) poorer final acuity (p=0.02). CONCLUSIONS: Eyes with myopic foveoschisis with preoperative ellipsoid disruption and thinner central foveal thickness tend to have poorer visual outcomes. While current surgical manoeuvres are effective in reattaching the fovea, they may also cause iatrogenic injury to the photoreceptors.

IMPORTANCE: To describe a cohort of patients with birdshot chorioretinopathy who did not manifest birdshot lesions on clinical examination but had retinal vasculitis, low-grade to moderate vitritis, and hypocyanescent lesions on indocyanine green angiography (ICGA). OBSERVATIONS: Case series of 3 patients with mild to moderate vitritis and retinal vasculitis without definite birdshot lesions on clinical examination evaluated from January 2007 to December 2014 at 4 academic ophthalmology centers. All patients' results were positive for human leukocyte antigen-A29. All cases had hypocyanescent lesions visible on ICGA but not detectable on fluorescein angiography. CONCLUSIONS AND RELEVANCE: Patients with retinal vasculitis and low-grade vitritis with or without macular edema may have birdshot chorioretinopathy evident on ICGA before lesions are visible on clinical examination or fluorescein angiography. Expanding birdshot chorioretinopathy diagnostic criteria to include the presence of hypocyanescent lesions on ICGA could improve the sensitivity of diagnosis.

PURPOSE: There is a need for automated retinal optical coherence tomography (OCT) image analysis tools for quantitative measurements in small animals. Some image processing techniques for retinal layer analysis have been developed, but reports about how useful those techniques are in actual animal studies are rare. This paper presents the use of a retinal layer detection method we developed in an actual mouse study that involves wild type and mutated mice carrying photoreceptor degeneration. METHODS: Spectral domain OCT scanning was performed by four experimenters over 12 months on 45 mouse eyes that were wild-type, deficient for ephrin-A2 and ephrin-A3, deficient for rhodopsin, or deficient for rhodopsin, ephrin-A2 and ephrin-A3. The thickness of photoreceptor complex between the outer plexiform layer and retinal pigment epithelium was measured on two sides of the optic disc as the biomarker of retinal degeneration. All the layer detection results were visually confirmed. RESULTS: Overall, 96% (8519 out of 9000) of the half-side images were successfully processed using our technique in a semi-automatic manner. There was no significant difference in success rate between mouse lines (p = 0.91). Based on a human observer's rating of image quality for images successfully and unsuccessfully processed, the odds ratios for 'easily visible' images and 'not clear' images to be successfully processed is 62 and 4, respectively, against 'indistinguishable' images. Thickness of photoreceptor complex was significantly different across the quadrants compared (p < 0.001). It was also found that the average thickness based on 4-point sparse sampling was not significantly different from the full analysis, while the range of differences between the two methods could be up to about 6 μm or 16% for individual eyes. Differences between mouse lines and progressive thickness reduction were revealed by both sampling measures. CONCLUSIONS: Although the thickness of the photoreceptor complex layer is not even, manual sparse sampling may be as sufficiently accurate as full analysis in some studies such as ours, where the error of sparse sampling was much smaller than the effect size of rhodopsin deficiency. It is also suggested that the image processing method can be useful in actual animal studies. Even for images poorly visible to human eyes the image processing method still has a good chance to extract the complex layer.

PURPOSE: To evaluate the correlation and agreement between optical coherence tomography (Cirrus HD-OCT) retinal nerve fiber layer (RNFL) thickness map and scan circle RNFL thickness measurements. METHODS: ImageJ and custom Perl scripts were used to derive RNFL thickness measurements from RNFL thickness maps of optic disc scans of healthy and glaucomatous eyes. Average, quadrant, and clock-hour RNFL thickness of the map, and RNFL thickness of the areas inside/outside the scan circle were obtained. Correlation and agreement between RNFL thickness map and scan circle RNFL thickness measurements were evaluated using R and Bland-Altman plots, respectively. RESULTS: A total of 104 scans from 26 healthy eyes and 120 scans from 30 glaucomatous eyes were analyzed. RNFL thickness map and scan circle measurements were highly reproducible (eg, in healthy eyes, average RNFL thickness coefficients of variation were 2.14% and 2.52% for RNFL thickness map and scan circle, respectively) and highly correlated (0.55≤R≤0.98). In general, the scan circle provided greater RNFL thickness than the RNFL thickness map in corresponding sectors and the differences tended to increase as RNFL thickness increased. The width of the 95% limits of agreement ranged between 5.28 and 36.80 μm in healthy eyes, and between 11.69 and 42.89 μm in glaucomatous eyes. CONCLUSIONS: Despite good correlation between RNFL thickness map and scan circle measurements, agreement was generally poor, suggesting that RNFL thickness assessment over the entire scan area may provide additional clinically relevant information to the conventional scan circle analysis. In the absence of available measurements from the entire peripapillary region, the RNFL thickness maps can be used to investigate localized RNFL thinning in areas not intercepted by the scan circle.