Topical anesthesia: possible risk factor for endophthalmitis after cataract extraction

PURPOSE: To assess the relationship between the risk for acute endophthalmitis after cataract extraction and whether certain factors, such as surgeon qualification, numerical order, duration of surgery, operating theater, and type of anesthesia (topical or retrobulbar), could be modified to decrease the risk. SETTING: Single-center academic practice. METHODS: Two epidemiological studies were performed: a case-control study and a retrospective cohort study. The surgical records of all patients with clinically diagnosed endophthalmitis within 30 days after cataract surgery performed between February 2002 and September 2003 were reviewed. The endophthalmitis cases were compared with 108 randomly selected controls (4 controls per case). The global incidence of endophthalmitis and the incidence according to type of anesthesia were calculated. RESULTS: Of 5011 cataract extractions performed, 27 cases of endophthalmitis occurred. The incidence was 5.39 per 1000 procedures. An independent statistically significant relationship was found between endophthalmitis and the use of topical anesthesia (odds ratio [OR], 11.8; 95% confidence interval [CI], 2.4-58.7) and surgery longer than 45 minutes (OR, 7.2; 95% CI, 1.7-29.7) but not between the other variables. The incidence of endophthalmitis was 1.8 per 1000 cataract extractions with retrobulbar anesthesia and 6.76 per 1000 with topical anesthesia (relative risk [RR], 3.76; 95% CI, 0.89-15.85). After the start of the study period was extended to May 2001, the incidence of endophthalmitis was 1.3 per 1000 cataract extractions with retrobulbar anesthesia and 8.7 per 1000 with topical anesthesia (RR, 6.72; 95% CI, 1.63-27.63). CONCLUSION: Results suggest that there may be an association between topical anesthesia and endophthalmitis after cataract extraction.