Wendy Hatch

Risk Factors for Acute Endophthalmitis after Cataract Surgery: A Population-based Study

OBJECTIVE To identify risk factors for suspected acute endophthalmitis after cataract surgery. DESIGN Population-based retrospective cohort. PARTICIPANTS Administrative data from more than 440,000 consecutive cataract surgeries in Ontario, Canada, from April 1, 2002, to March 31, 2006. METHODS Consecutive physician billing claims for cataract surgery and specific intraoperative and postoperative procedures related to complications of cataract surgery were identified. Acute endophthalmitis was defined using surrogate markers for intraocular infection, including vitrectomy, vitreous injection, or aspiration procedures not in combination with air/fluid exchange or dislocated lens extraction, performed 1 to 14 days after cataract surgery. Anterior vitrectomy performed on the day of surgery was used as a surrogate marker for capsular rupture. MAIN OUTCOME MEASURES Overall rates of endophthalmitis were calculated and grouped by patient demographics, surgical facility, season, year, and association with capsular rupture. RESULTS There were 617 suspected acute endophthalmitis cases of 442,177 cataract surgeries over the 4 years. The overall unadjusted and adjusted rates of suspected acute endophthalmitis were both 1.4 per 1000 cataract surgeries. Men had higher rates than women (1.70 vs. 1.19/1000 surgeries, P<0.0001) with an adjusted odds ratio of 1.40 (95% confidence interval, 1.19-1.64).The oldest age group (>or= 85 years) had the highest rate (2.18/1000), and the youngest group (20-64) had the second highest rate (1.76/1000). The endophthalmitis rates for these age groups were significantly different from those aged 65 to 84 years. The endophthalmitis rate was approximately 10-fold higher in those with capsular rupture compared with those without (13.11 vs. 1.34/1000, P<0.0001), with an adjusted odds ratio of 9.56 (95% confidence interval, 6.43-14.2). CONCLUSIONS The overall rates of suspected acute endophthalmitis are low but significantly higher in certain patient groups. Our population-based analysis can be used as a benchmark for quality-improvement initiatives and can assist clinicians in educating their patients regarding the risks associated with cataract surgery. Future work is required to address the higher rate of endophthalmitis in men, those with capsular rupture, and the oldest patients undergoing cataract surgery.

Association between tamsulosin and serious ophthalmic adverse events in older men following cataract surgery.

CONTEXT Both benign prostatic hyperplasia (BPH) and cataract formation are common in older men. The alpha-adrenergic receptor blocker tamsulosin is frequently prescribed to treat BPH, and research suggests this drug may increase the intraoperative difficulty of cataract surgery. No studies have documented whether use of tamsulosin or other alpha-blocker drug therapies affect the risk of serious postoperative adverse events. OBJECTIVE To assess the risk of adverse events following cataract surgery in older men prescribed tamsulosin or other alpha-blocking drugs used to treat BPH. DESIGN, SETTING, AND PATIENTS Nested case-control analysis of a population-based retrospective cohort study using linked health care databases from Ontario, Canada. We included all men aged 66 years or older who had cataract surgery between 2002 and 2007 (N = 96 128). MAIN OUTCOME MEASURES A composite of procedures signifying retinal detachment, lost lens or lens fragment, or endophthalmitis occurring within 14 days after cataract surgery. The risk of these adverse events was compared between men treated with tamsulosin or other alpha-blockers and men with no exposure to these medications in the year prior to cataract surgery. We separately examined the association of drug exposure that was either recent (within the 14 days before surgery) or previous (15-365 days before surgery). RESULTS Overall, 3550 patients (3.7%) in the cohort had recent exposure to tamsulosin and 7426 patients (7.7%) had recent exposure to other alpha-blockers. Two hundred eighty-four patients (0.3%) had an adverse event. We randomly matched 280 of the cases to 1102 controls according to their age, surgeon, and year of surgery. Adverse events were significantly more common among patients with recent tamsulosin exposure (7.5% vs 2.7%; adjusted odds ratio [OR], 2.33; 95% confidence interval [CI], 1.22-4.43) but were not associated with recent exposure to other alpha-blockers (7.5% vs 8.0%; adjusted OR, 0.91; 95% CI, 0.54-1.54) or to previous exposure to either tamsulosin (< or = 1.8% vs 1%; adjusted OR, 0.94; 95% CI, 0.27-3.34) or other alpha-blockers (2.9% vs 2.1%; adjusted OR, 1.08; 95% CI, 0.47-2.48). This corresponds to an estimated number needed to harm (NNH) of 255 (95% CI, 99-1666). CONCLUSIONS Exposure to tamsulosin within 14 days of cataract surgery was significantly associated with serious postoperative ophthalmic adverse events. There were no significant associations with exposure to other alpha-blocker medications used to treat BPH.