Ketamine Neuroprotection in the Rabbit Retina after Pars Plana Vitrectomy with Silicone Oil Tamponade

Abstract

Abstract: : Purpose: To verify the neuroprotective potential of ketamine in the rabbit retina after pars plana vitrectomy with silicone oil tamponade. Methods: Twenty young albino rabbits underwent standard three port pars plana vitrectomy with intravitreal silicone oil injection. The rabbits were then randomized into 2 groups. Group I received an intramuscular daily dose of 50 mg/ml of ketamine and group II received an intramuscular daily injection of saline. The animals were euthanized 4 weeks after vitrectomy and the eyes processed for light microscopy. Qualitative and quantitative analysis of the retinal cells were made using Zeiss Axioplot microscope and KS400 software (Carl Zeiss Vision).Results: Light microscopy showed a higher rate of picnotic nuclei in retinas from group II. Group I retinal cell density from the inner nuclear and ganglionar cell layers was significantly higher (student's-t-test) in group I retinas when compared to Group II. Although retinal cell density from the outer nuclear layer was higher in Group I, the difference was not statiscally significant. Conclusions: Ketamine was effective in reducing retinal cell death related to silicone oil injury one month after vitrectomy.

Keywords: neuroprotection • retina • pharmacology