Antibiotic choice for the prophylaxis of post-cataract extraction endophthalmitis

To determine the 8-year incidence of endophthalmitis after cataract surgery and to determine which surgical practices were associated with higher rates of endophthalmitis.

Case-control study.

A total of 75 318 eyes undergoing cataract extractions, performed by 26 different surgeons at 4 public hospitals and 5 nonhospital surgical facilities.

Cases of endophthalmitis were acquired using a detailed, prospectively designed demographic database. Controls were tabulated using volume data available from the provincial health care system.

The primary outcome was the development of endophthalmitis.

A total of 23 cases (13 with culture-positive results) of postoperative endophthalmitis occurred, yielding an overall 8-year incidence of 0.03%. The incidence of endophthalmitis varied between surgeons from 0% to 0.20%. Two surgeons had higher rates than the rest of the group: 1 high-volume surgeon (1059.4±231.9 mean cases per year) with an incidence of 0.08% (n = 7; P = 0.004) and 1 low-volume surgeon (123.5±44.8 mean cases per year) with an incidence of 0.20% (n = 2; P = 0.002). On univariate analysis, the rate of endophthalmitis was not influenced by the use of intracameral (0.898) or subconjunctival antibiotics (0.331), whereas the use of moxifloxacin was associated with a lower rate of endophthalmitis (P = 0.029). Surgery at 1 private facility (P = 0.046) and the use of timolol at the end of the procedure (P = 0.007) were associated with a higher rate of endophthalmitis. Multivariate analysis demonstrated that the odds of endophthalmitis was lower if a second-generation (P = 0.02) or fourth-generation (P = 0.008) fluoroquinolone antibiotic was used after surgery. In contrast, the odds of endophthalmitis occurring was higher if timolol (P = 0.0002) was used at the end of the procedure or if the surgery was performed at one of the private facilities (P = 0.009).

The rate of endophthalmitis was lower if a fluoroquinolone was used after surgery. In contrast, endophthalmitis was more likely to occur if timolol was used at the end of the procedure or if surgery was performed at one of the private facilities.