Comparative Effectiveness of Antibiotic Prophylaxis in Cataract Surgery.

Purpose: Intracameral injection is an effective method for preventing infection, but no controlled study has been published in the United States.

Design: We conducted an observational, longitudinal cohort study to examine the effect of topical and injected antibiotics on risk of endophthalmitis.

Participants: We identified 315 246 eligible cataract procedures in 204 515 members of Kaiser Permanente, California, 2005-2012.

Methods: The study used information from the membership, medical, pharmacy, and surgical records from the electronic health record.

Main Outcome Measures: The adjusted odds ratio (OR) and 95% confidence interval (CI) for the association of antibiotic prophylaxis (route and agent) with risk of endophthalmitis was estimated using logistic regression analysis.

Results: We confirmed 215 cases of endophthalmitis (0.07% or 0.7/1000). Posterior capsular rupture was associated with a 3.68-fold increased risk of endophthalmitis (CI, 1.89-7.20). Intracameral antibiotic was more effective than topical agent alone (OR, 0.58; CI, 0.38-0.91). Combining topical gatifloxacin or ofloxacin with intracameral agent was not more effective than using an intracameral agent alone (compared with intracameral only: intracameral plus topical, OR, 1.63; CI, 0.48-5.47). Compared with topical gatifloxacin, prophylaxis using topical aminoglycoside was ineffective (OR, 1.97; CI, 1.17-3.31).

Conclusions: Surgical complication remains a key risk factor for endophthalmitis. Intracameral antibiotic was more effective for preventing post-cataract extraction endophthalmitis than topical antibiotic alone. Topical antibiotic was not shown to add to the effectiveness of an intracameral regimen.