Intravitreal saline injection ameliorates laser-induced retinal damage in rats.

Abstract

PURPOSE: Injury to the central nervous system has been shown to trigger a physiologic response in the form of some degree of natural self-repair. This beneficial reaction may be boosted by appropriate preconditioning via a reversible injury to the retina. Here we report the ameliorative effect of intravitreal saline injection on laser-induced retinal damage. METHODS: Standard argon laser lesions (514 and 544 nm, 200 &#x3bc;m, 0.1 W, 0.05 seconds) were induced in the eyes of 36 Dark Agouti pigmented rats and immediately followed by injection of saline either intravitreally (5 &#x3bc;L) or intravenously (0.5 mL). Lesions were evaluated histologically and morphometrically after 3, 20, and 60 days. RESULTS: At all 3 time points, the eyes of rats injected intravitreally showed less laser-induced retinal cell loss (P < 0.05) and smaller lesion diameters (P < 0.05) than those of intravenously injected rats. CONCLUSION: Intravitreal saline injection evidently has a neuroprotective effect on the rat retina. The mechanism of action of this effect should be further elucidated and its clinical applicability tested.