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Objective To determine the safety and efficacy of the artificial silicon retina (ASR) microchip implanted in the subretinal space to treat vision loss from retinitis pigmentosa. Methods The ASR microchip is a 2-mm-diameter silicon-based device that contains approximately 5000 microelectrode-tipped microphotodiodes and is powered by incident light. The right eyes of 6 patients with retinitis pigmentosa were implanted with the ASR microchip while the left eyes served as controls. Safety and visual function information was collected. Results During follow-up that ranged from 6 to 18 months, all ASRs functioned electrically. No patient showed signs of implant rejection, infection, inflammation, erosion, neovascularization, retinal detachment, or migration. Visual function improvements occurred in all patients and included unexpected improvements in retinal areas distant from the implant. Main Outcome Measures Subjective improvements included improved perception of brightness, contrast, color, movement, shape, resolution, and visual field size. Conclusions No significant safety-related adverse effects were observed. The observation of retinal visual improvement in areas far from the implant site suggests a possible generalized neurotrophic-type rescue effect on the damaged retina caused by the presence of the ASR. A larger clinical trial is indicated to further evaluate the safety and efficacy of a subretinally implanted ASR. [ABSTRACT FROM AUTHOR]

Objective: To determine whether consistent tissue effects are obtained when laser lesions are produced with a commercially available diode laser that are near the limit of clinical detection at the time of treatment. Methods: Continuous-wave or micropulse diode laser was used to produce clinically undetectable (subthreshold) or barely detectable (threshold) retinal lesions in pigmented rabbits. Tissue effects at intervals after treatment were determined in retinal pigment epithelial (RPE) whole mounts by fluorescence microscopy, and in sections of retina and RPE by light and electron microscopy. Results: Continuous-wave and micropulse laser lesions that were originally clinically undetectable were detectable as zones of pigment mottling after 5 days. By microscopy, compaction and/or swelling was seen in the outer retina, and cells in the RPE monolayer became heterogeneous in size, shape, and pigmentation, but the tissue responses in the outer retina and RPE were variable even within and among lesions in the same eye. Conclusions: Subthreshold energies used to create both continuous-wave and micropulse laser lesions produced variable effects on the RPE and the overlying neurosensory retina. It appears that, near the minimum effective dose of laser irradiation, individual RPE cell heterogeneity becomes detectable as variability in sensitivity to laser injury. Clinical Relevance: As laser energy is reduced to limit collateral tissue damage in clinical applications, it may be difficult to generate reproducible lesions because of heterogeneity among individual cells. [ABSTRACT FROM AUTHOR]

A case study of 70 year old woman who developed isolated vitreoretinal amyloidosis in the absence of transthyretin mutations is studied. Vitreoretinal amyloidosis is believed to be associated with mutations in the genes encoding transthyretin and found exclusively as part of the familial amyloidotic polyneuropathy (FAP) syndrome. Dialated fundus examination showed multiple, white, refractile vitreous opacities dispersed in a syneretic vitreous in both eyes. Yellow deposits were also seen. A therapeutic and diagnostic left vitrectomy was then performed. Histopathologic analysis shows amyloidosis. Genomic DNA was then isolated from peripheral blood, and exons corresponding to the entire tsansthyretin protein were amplified by the polymerase chain reaction. Direct DNA sequence analysis of the amplified fragments revealed no mutations.

This article presents case studies of two 2 patients who developed ocular findings consistent with Unilateral acute idiopathic maculopathy (UAIM) , an inflammatory process involving the outer retina and retinal pigment epithelium (RPE) of the macula, shortly after developing classic signs and symptoms of hand-foot-and-mouth disease. It is believed that coxsackievirus, which causes hand-foot-and-mouth disease, may also cause UAIM. Both patients developed relatively rapid loss of central vision with signs of acute lesions in the outer retina and RPE. The changes healed with return of vision and the appearance of a bull's-eye type of scar.These ocular findings and the associated viral prodrome are typical of UAIM.