Effect of Intravitreal Dexamethasone in Treatment of Pneumococcal Endophthalmitis in Rabbits

PURPOSE: To investigate whether corticosteroid therapy would decrease the inflammation and tissue damage associated with pneumococcal endophthalmitis. METHODS: Albino rabbits were injected intravitreally with 1000 live organisms of Streptococcus pneumoniae and randomized after 24 hours to treatment with intravitreal vancomycin hydrochloride alone (n = 10), combination intravitreal vancomycin and intravitreal dexamethasone (n = 10), or no treatment (n = 10). After 2 weeks, the eyes were examined clinically and enucleated for histopathologic examination. RESULTS: Eyes treated with vancomycin and dexamethasone had significantly less intraocular inflammation and more preservation of retinal tissue than untreated eyes or eyes treated with vancomycin alone (P < .05, Fisher's exact test). Untreated and vancomycin-treated eyes were indistinguishable on clinical and histologic examination. Marked anterior and posterior segment inflammation with total retinal necrosis was noted in eyes from both groups. CONCLUSION: Intravitreal corticosteroid therapy may play an important role in minimizing the inflammation and tissue damage associated with pneumococcal endophthalmitis.