The epidemiology of acute endophthalmitis after cataract surgery in an Asian population

Abstract

Objective: To describe the incidence, risk factors, and clinical outcome of acute endophthalmitis after cataract extraction in a multiethnic Asian population.

Design: Prospective case series.

Participants: All patients with cataract extractions performed at the Singapore National Eye Center from 1996 to 2001.

Methods: Data on patients with acute endophthalmitis cases presenting within 6 weeks after cataract surgery were prospectively collected in a standardized format.

Main outcome measures: Acute endophthalmitis after cataract surgery.

Results: During the study period, 44 803 cataract operations (25 476 phacoemulsification and 19 327 extracapsular cataract extractions) were performed. There were 34 cases of acute endophthalmitis (average annual incidence of 0.076%), 21 of which were culture positive (average annual incidence of 0.040%). In multivariate analysis, risk of endophthalmitis was associated with phacoemulsification technique (relative risk [RR], 1.9; 95% confidence interval [CI], 0.9, 3.9; P = 0.10 for all endophthalmitis cases; RR, 3.1; 95% CI, 1.1, 9.4; P = 0.04 for culture-positive endophthalmitis cases) and the occurrence of intraoperative posterior capsule rupture (RR, 8.0; 95% CI, 3.1, 20.7; P<0.001 for all endophthalmitis cases; RR, 11.0; 95% CI, 3.7, 23.9; P<0.001 for culture-positive endophthalmitis cases). After a median follow-up of 234 days, half of the eyes achieved a final best-corrected visual acuity of 20/40. Predictors of this visual acuity included baseline acuity of counting fingers or better, culture-negative endophthalmitis, or infection caused by coagulase-negative Staphylococcus.

Conclusion: The incidence of acute endophthalmitis after cataract extraction in Singapore is consistent with rates reported elsewhere. The phacoemulsification technique is associated with a higher risk of acute culture-positive endophthalmitis compared with extracapsular cataract extraction. Intraoperative posterior capsule rupture is associated with an 8- to 11-fold higher risk of acute endophthalmitis, suggesting that these eyes should be closely monitored for signs of infection in the immediate postoperative period.