Abstract
Abstract: :
Purpose: Previously we reported that persistent subretinal indocyanin green (ICG) induced retinal atrophy after macular hole surgery (Hirata,et al. Am J Ophthalmol, in press). This study was designed to investigate the effects of subretinal ICG on retinal morphology in rabbit eyes. Methods: Retinal bleb detachments, 3mm in diameter, were produced by the injection of ICG at a dose of 25 mg/ml, 5 mg/ml, 0.5 mg/ml or balanced salt solution (BSS) into the subretinal space of albino rabbit eyes using a 20G needle with 41G cannula. No vitrectomy was performed. Retinal toxicity by subretinal ICG and BSS was assessed histologically by light microscopy at 2 weeks after injection. In eyes with 5 mg/ml ICG, retinal toxicity was assessed histologically at 1 day, 3days, 1 week, 2 weeks, 1 month after injection. Results: In eyes with 25 mg/ml and 5 mg/ml ICG at 2 weeks after injection, loss of the retinal pigment epithelium and photoreceptors, and retinal atrophy was observed. In eyes with 25 mg/ml ICG, the retinal structure was destroyed more severely than with 5 mg/ml. In eyes with 5 mg/ml ICG, normal structure of the retina was preserved at 1 day after injection. However, the photoreceptors were disappeared at 3days after injection, and retinal atrophy occured. In eyes with 0.5 mg/ml ICG and BSS, normal structure of the retina was preserved and folding of the neural retina was partly observed by light microscopy. Conclusions: Subretinal ICG induces apparent morphological damage of the retina in a dose-dependent manner. ICG may be introduced into the subretinal space through an original or iatrogenic hole during vitreous surgery. Care should be taken when using intravitreous ICG.
Keywords: vitreoretinal surgery • animal model • retina