Bacterial endophthalmitis after small-incision cataract surgery: effect of incision placement and intraocular lens type

Abstract

Purpose To determine whether endophthalmitis after small-incision cataract surgery is affected by the incision site (superior sclerocorneal versus temporal cornea) or the foldable intraocular lens (IOL) material (silicone versus acrylic). Setting Multicenter study. Methods Patients who had small-incision cataract surgery at Toyama Medical and Pharmaceutical University Hospital and affiliated hospitals from March 1998 to March 2001 were examined prospectively. The patients were randomized into 3 groups. In Group A, an acrylic IOL (MA60BM, Alcon) was implanted through a temporal corneal incision. In Group B, an acrylic IOL (MA60BM) was implanted via a superior sclerocorneal incision. In Group C, a silicone poly(methyl methacrylate) IOL (SI-40NB, Allergan) was implanted via a superior sclerocorneal incision. Each patient was followed for more than 6 months. Results Initially, 7622 patients (12 317 eyes) agreed to participate in the study. The final study included 3831 eyes in Group A, 3901 eyes in Group B, and 3863 eyes in Group C. Postoperative endophthalmitis was diagnosed clinically in 11 eyes (0.29%) in Group A, 2 (0.05%) in Group B, and 2 (0.05%) in Group C. Endophthalmitis proven by culture was found in 9 eyes in Group A, 2 in Group B, and 2 in Group C. The incidence of endophthalmitis in Group A was higher than in the other groups. The incidence of endophthalmitis in Group B was similar to that in Group C. The relative risk of postoperative endophthalmitis proven by culture in Groups B and C was 4.6 times ( P = .037) lower than in Group A. Conclusion The findings suggest that a temporal corneal incision may lead to an increased risk of postoperative endophthalmitis and that the IOL material does not affect the incidence of this complication.