Therapy Of High Dose Methylprednisolone In Laser Injury Of Rat Retina

the efficacy of high-dose methylprednisolonein argon-laser-induced retinal injury in rat was evaluated inthis research.40 SD rats were inflicted with severe retinallaser burns Within l hour after retinal laser photocoagulationthe methylprednisolone was given to 20 rats of treatment groupby intraperitoneal injection with dose of 30 mg/kg which lastedfor 3 days. At day 3,7,l4,28 after coagulation, the eyeswere enucleated, fixed and cut into tissue sections.In the flrst part of the rearch, the laser leisions of ratretina were assessed by histopathologic and morphometriccriteria. Histopathologic examination showed significantbeneficial effect of treatment to control. Morphometrically thecomparision of the width of disrupted outer nuclear layer andthe percentage of residual photoreceptor nuclei in the laserleision between two groups showed the neuropretetive effect ofhigh-dose methylprednisolone due to inhibition of lipidperoxidation.In the second part,the laser leisions were examined byimmunohistochemistry. The results showed that the expresslonof the PCNA and GFAP was decreased in the treatment groupof methylprednisolone The expression of bFGF was nodifferent between two groups. The expression of Cytokeratinshowed the retinal pigment eplthelium cells of the controlgroup were damaged more heavily and proliferated morestro ng l y than th e t re at ment gro up. Th e re su l ts co nfi rmed thene urop retet iv e effect o f h igh-do se m ethy lpredn iso lon e. Thec o nc l us ion was drawed fro m the two p arts of the re searchthat the high dose of mcthyprednisolone had theneuroprotectlve effect on the laser-lnduced retlnal injury inr a t.