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: 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.
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.
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: 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.
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.
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.