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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 fromretinitis pigmentosa. Methods The ASR microchip is a 2-mm-diameter silicon-based device that containsapproximately 5000 microelectrode-tipped microphotodiodes and is powered byincident light. The right eyes of 6 patients with retinitis pigmentosa wereimplanted with the ASR microchip while the left eyes served as controls. Safetyand visual function information was collected. Results During follow-up that ranged from 6 to 18 months, all ASRs functionedelectrically. No patient showed signs of implant rejection, infection, inflammation,erosion, neovascularization, retinal detachment, or migration. Visual functionimprovements occurred in all patients and included unexpected improvementsin 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 observationof retinal visual improvement in areas far from the implant site suggestsa possible generalized neurotrophic-type rescue effect on the damaged retinacaused by the presence of the ASR. A larger clinical trial is indicated tofurther evaluate the safety and efficacy of a subretinally implanted ASR.

Objective: To determine the visual results, recurrence rates, and postoperative complications of surgical removal of subfoveal choroidal neovascularization (CNV) in patients with the presumed ocular histoplasmosis syndrome. Design: A consecutive surgical series of 63 eyes of 62 patients with subfoveal CNV and the presumed ocular histoplasmosis syndrome with longer than 6 months of follow-up. Setting: Tertiary care university medical center. Methods: Patients underwent surgical removal of subfoveal CNV using vitreoretinal surgical techniques. The anatomical and functional results of surgery were analyzed. Results: The median age of the patients was 42 years (range, 16-68 years), and the median follow-up time was 24 months (range, 6-48 months). Visual acuity improved by 2 or more Snellen lines in 22 (35%) of the 63 eyes, was unchanged in 28 (44%) of the eyes, and worsened in 13 (21%) of the eyes. Eleven (17%) of the 63 eyes improved to a visual acuity of 20/50 or better. Eyes with an initial visual acuity of 20/200 or worse had a better prognosis for improved vision (ie, 26 [41%] of the eyes) than those with an initial visual acuity of 20/100 or better (ie, 5 [8%] of the eyes). Recurrence of the subfoveal CNV occurred in 24 (38%) of the 63 eyes and was more common in those eyes that received preoperative laser photocoagulation (ie, 15 [47%] of the eyes). The median time to recurrence was 5 months after surgery. Postoperative complications included macular striae in 4 (6%) of the 63 eyes, rhegmatogenous retinal detachment in 2 (3%) of the eyes, retinal tear in 1 (1.6%) of the eyes, and progression of cataract in 19 (30%) of the eyes. Conclusions: Surgical excision of subfoveal CNV may be an effective therapeutic modality in patients with the presumed ocular histoplasmosis syndrome that offers the possibility of improving central vision in many patients. Factors possibly associated with a favorable visual prognosis include younger patient age and the absence of previous laser photocoagulation.