Prophylactic intracameral cefazolin after cataract surgery: endophthalmitis risk reduction and safety results in a 6-year study.

Purpose: To assess the use of intracameral cefazolin in preventing endophthalmitis in cataract surgery.

Setting: Ophthalmology Department, L'Hospitalet de Llobregat, Barcelona, Spain.

Methods: This study was of phacoemulsification procedures performed from January 2002 to December 2007. In January 2004, intracameral cefazolin given at the end of the surgery was added to the prophylaxis protocol of cataract surgery. The cumulative incidence of postoperative endophthalmitis before and after the addition of intracameral cefazolin was compared.

Results: During the study period, 18579 phacoemulsification procedures were performed. In the 2-year period before introduction of intracameral cefazolin prophylaxis, 25 cases of endophthalmitis were diagnosed in 5930 surgeries, leading to a cumulative incidence of 0.422% (95% confidence interval [CI], 0.279%-0.613%). After the introduction of cefazolin, 6 cases of endophthalmitis were diagnosed in 12649 surgeries, an incidence of 0.047% (95% CI, 0.019%-0.099%). When only microbiologically proven cases were considered, the cumulative endophthalmitis incidence was 0.388% (95% CI, 0.252%-0.572%) in the first study period and 0.032% (95% CI, 0.010%-0.076%) in the second study period (P<.0000001). The relative risk for presenting with endophthalmitis in the first study period compared with the second period was 8.89 (95% CI, 3.65-21.65).

Conclusions: A 2.5 mg/0.1 mL intracameral bolus of cefazolin provided excellent prophylactic effectiveness, with a reduction in the incidence of endophthalmitis from 0.422% to 0.047%, corresponding to a relative risk reduction of 88.7% (95% CI, 72.6%-95.4%). Cefazolin fulfills international recommendations on antimicrobial prophylaxis for surgical site infections and is easier to obtain in developing countries.