Epidemiological and health economical evaluation of intraoperative antibiosis as a protective agent against endophthalmitis after cataract surgery.

OBJECTIVE To evaluate risk factors for endophthalmitis after cataract surgery and to retest recent findings on the protective effect of intraoperative antibiosis and the promoting effect of the clear corneal as compared to sclerocorneal incision. In addition, the economics of intraocular intraoperative antibiosis as a prophylaxis in cataract surgery are asketched. DESIGN Survey study. PARTICIPANTS Five hundred thirty-eight ophthalmosurgical centres in Germany. MAIN OUTCOME MEASURE epidemiological evaluation: responder specific endophthalmitis incidence in year 2000; economical evaluation: direct cost analysis based on incidence data and local cost estimates (health service's perspective). RESULTS A total of 310 (58%) questionnaires were computed resulting in an overall count of 404,356 cataract surgeries and 291 self-reported endophthalmitis cases (crude rate 0.072%). The risk of postoperative endophthalmitis for sclerocorneal versus clear corneal incisions was not significantly reduced (relative risk 0.97, 99% confidence interval 0.69-1.38). The hypothesis of a protective effect of intraocular antibiosis could be confirmed by a significantly decreased risk ratio of 0.69 (99% confidence interval 0.48-0.99) indicating a significant benefit from intraoperative intraocular antibiosis. A similar tendency was observed for an intraoperative periocular antibiosis with a significantly reduced risk ratio of 0.68 (99% confidence interval 0.49-0.96). These risk estimates had been adjusted for the size of the surgical centre: a significantly reduced risk ratio of 0.70 (99% confidence interval 0.49-0.98) for postoperative endophthalmitis was observed for local centres. Cost evaluation for the prophylactic use of intraocular intraoperative antibiosis in cataract surgery revealed an economically relevant decrease in direct endophthalmitis associated costs. CONCLUSIONS Whereas this 2000 appraisal of a recent survey in 1996 could not reproduce the benefit of sclerocorneal incision, the protective effect of intraoperative intraocular antibiotic prophylaxis could be confirmed. However, the results of this survey have to be interpreted with care, since it is not based on individual case information, but rather on aggregate questionnaire data.