Incidence of endophthalmitis and impact of prophylaxis with cefuroxime on cataract surgery.

PURPOSE To evaluate the clinical and economic impact of prophylactic administration of intracameral cefuroxime on cataract surgery. SETTING Hospital Universitario Fundación Alcorcón, Madrid, Spain. DESIGN Quasi-experimental study with before and after analysis. METHODS The evolution of the cumulative incidence of endophthalmitis before and after (October 2005) administration of intracameral cefuroxime as endophthalmitis prophylaxis in cataract surgery was studied. The annual incidence adjusting to a Poisson distribution was compared. The effectiveness of the prophylaxis was evaluated with the relative risk (RR). The impact of cefuroxime was evaluated with the attributable risk fraction and the number of patients needed to treat to avoid a case of endophthalmitis. RESULTS Cataract surgery was performed in 19 463 patients, 6595 patients before and 12 868 patients after October 2005. Endophthalmitis was diagnosed in 44 cases (39 before and 5 after). Positive microbiology cultures were obtained in 29 patients (66%). The overall cumulative incidence was 0.23 cases per 100 patients. Cefuroxime protected against endophthalmitis (RR = 0.06; P<.05; 95% confidence interval [CI], 0.03-0.17); the impact or number needed to treat was 182, and the attributable risk fraction was -0.93% (P<.05; 95% CI, -0.82 to -0.97). The cost of a dose of cefuroxime was €1, and the cost of a case of endophthalmitis was €1358. The potential saving with cefuroxime was €1177 for every 182 patients treated. CONCLUSION Intracameral cefuroxime reduced the incidence of endophthalmitis in cataract surgery and had a high clinical and economic impact on its prevention.