Abstract
Abstract: :
Purpose: Antibiotics are widely used during and after retinal detachment repair. The purpose of this experiment is to characterize the effects of ampicillin, ofloxacin, ceftriaxone, and fosfomycin on photoreceptor apoptosis in a rat model of retinal detachment. Methods: Retinal detachments were created in Brown Norway rats by injecting 10% hyaluronic acid into the subretinal space using a transvitreous approach. Ampicillin (100 mg/kg/day), ofloxacin (6 mg/kg/day), ceftriaxone (50 mg/kg/day), and fosfomycin (20 mg/kg/day) were injected intraperitoneally on the day of detachment induction and for the two following days (n = 6 eyes for each antibiotic). Control animals received saline intraperitoneal injections on the day of detachment induction and for the two following days (n = 6 eyes). All eyes were enucleated 72 hours after retinal detachment induction, embedded in paraffin and sectioned every 6 µm. Light microscopy and terminal dUTP–biotin nick end–labeling (TUNEL) was performed to assay for morphologic features associated with apoptosis. TUNEL–positive cells were counted by a masked observer. The mean number of TUNEL–positive cells was determined by averaging the number of TUNEL–positive cells in three sections of each eye. Results:Light microscopic analysis of detached retinas showed the presence of pyknotic nuclei in the outer nuclear layer and disruption of the normal organization of the photoreceptor outer segments. TUNEL–staining was positive in the outer nuclear layer only in the detached portions of retina. The mean number of TUNEL–positive cells was greater in control eyes (mean ± SD, 86.2 ± 34.3) vs. eyes of animals treated with ampicillin (54.1 ± 25.5), ofloxacin (49.4 ± 21.1), ceftriaxone (37.4 ± 13.8), and fosfomycin (56.5 ± 42.2). However, these differences were statistically significant for ofloxacin and ceftriaxone (p = 0.05 and 0.009, respectively) but not for ampicillin or fosfomycin (p = 0.10 and 0.21, respectively). Conclusions: These preliminary data suggest that systemic administration of the antibiotics ofloxacin and ceftriaxone may decrease photoreceptor apoptosis associated with retinal detachment.
Keywords: retinal detachment • apoptosis/cell death • antibiotics/antifungals/antiparasitics