Risk factors for development of post-trabeculectomy endophthalmitis

Background/aims-Although adjunctive use of antiproliferative agents improve s the success rate of glaucoma filtration surgery it profoundly alters the morphology of the filtering bleb. In view of these structural changes, whic h have been suggested to predispose to bleb infection, the relative importa nce of potential risk factors in the development or posttrabeculectomy endo phthalmitis was investigated. Methods-A case-control study was performed on patients with posttrabeculect omy endophthalmitis presenting to a single academic centre over a 61/2 year period. Cases were diagnosed by the combination of vitreous and aqueous in flammation occurring 4 or more weeks postoperatively with control patients chosen by selecting the three patients undergoing trabeculectomy immediatel y following each index case. Results-Analysis of these data, derived from 23 cases and 69 controls, demo nstrated that an episode of blebitis and the presence of diabetes mellitus were statistically significantly associated with subsequent endophthalmitis (odds ratios (OR) 11.8, 95% CI: 2.21-88.31, p = 0.003 and OR 4.51, 95 % CI 1.02-20.29, p = 0.04 respectively). The data also suggest arn association exists between antiproliferative use and endophthalmitis (OR 3.3, 95% CI 0. 95-15.19, p = 0.07) as the time interval between filtration surgery and dev elopment of endophthalmitis was significantly shorter in patients treated w ith antiproliferative agents (p = 0.001). Conclusions-These results provide strong evidence of an increased risk of l ate endophthalmitis in patients who have diabetes mellitus or have had an e pisode of blebitis and suggest antiproliferative agents may also have an im portant role.