Anti-inflammatory therapy in acute periods of chronic ischemic retinal injury in rats

Abstract

Background. Retinal ischemia results from retinal vascular occlusion or develops as a complication of diabetes mellitus, glaucoma, and various neovascular diseases. Ischemic injury is definitely related with an inflammatory response and activation of the arachidonic acid cascade. For this reason, the aim of this study was to examine the course of changes in ischemic injury of rat retina and the effect of blocking the arachidonic acid cascade at early stages. Methods. Retinal ischemia was simulated by bilateral occlusion of internal carotid arteries (ICA) in Wistar male rats. Lornoxicam (non-selective cyclooxygenase inhibitor), triamcinolone (phospholipase A2 inhibitor), and saline were injected intravitreally at 15 min following ICA bilateral occlusion and intraperitoneally at 24 h and 48 h. The fundus was examined using ophthalmoscopy before the operation and at 7, 14, 28, 56, and 180 days following the occlusion. Enucleation was conducted for histological analysis on the same days. Results. Lornoxicam administered at early stages exerted a long-term protective effect on the ischemic retina. Effects of triamcinolone were controversial, brief, and associated with impaired general state of animals. Therefore, prostaglandin synthesis inhibitors might be used as a therapy for retinal ischemic disease.