Endophthalmitis incidence holds steady in United Kingdom

The retrospective investigation extracted information from a computerized database of surgical activity, case notes, and the hospital morbidity coding system at the Birmingham & Midland Eye Centre, Birmingham, England, which serves a population of about 3 million. The study analyzed consecutive cases of endophthalmitis occurring between April 1997 and November 2004. Eyes were included if they presented with features of endophthalmitis within 6 weeks after cataract surgery.

A total of 101 cases were identified among 101,920 total procedures, yielding an overall annual incidence of post-cataract surgery endophthalmitis of 0.099%. Analyses of annual incidence rates for each year of the study showed some fluctuation, with rates ranging from a low of 0.053% to a maximum of 0.191%.

"The incidence of post-cataract surgery endophthalmitis has been reported to have increased over the past 15 to 20 years, perhaps as a result of conversion to clear cor-nea surgery," said Dr. Durrani, clinical lecturer, University of Birmingham. "That background prompted us to conduct a study to determine the incidence of this rare-but-devastating complication in our own regional center.

"Our study has limitations that make it difficult to draw conclusions," he said. "Its sample size is relatively small compared with the recently reported Medicare billing data study. It also represents experience of surgeons with varying levels of expertise using different draping practices and working in more than a dozen operating suites.

"However, those features also make our study quite robust because it represents a real-world setting," continued Dr. Durrani, who is also an oculoplastic and orbital fellow, Moorfields Eye Hospital, London. "Perhaps routine use of preoperative skin cleaning and fornix irrigation with povidone-iodine is one explanation for the observed stability in the endophthalmitis rate at our center."

The 101 cases of post-cataract surgery endophthalmitis occurred among patients with a mean age of 71 years (range, 24 to 94). The affected patients were predominantly female (about two-thirds), and there was a preponderance of left versus right eyes (61 versus 40).

The clinical study was also undertaken to evaluate the diagnostic utility of anterior chamber (AC) tap and vitreous biopsy as well as to characterize the spectrum of microbial pathogens and their antibiotic sensitivities. Those analyses were based on a series of 116 endophthalmitis cases.