Bacterial Contamination of the Eye during Extracapsular Cataract Surgery

Abstract

OBJECTIVE: To ascertain the nature and degree of bacterial and fungal contamination of the eye immediately before, during and after extracapsular cataract extraction and posterior chamber implantation. DESIGN: Prospective single blind study. SETTING: Ophthalmic operating theatre in District General Hospital. PATIENTS: 54 patients undergoing routine extracapsular cataract surgery and lens implantation. MAIN OUTCOME MEASURES: The proportion of eyes from which bacterial (or fungal) growth was obtained and the nature of the organisms isolated. RESULTS: Bacterial growth was obtained from at least one source in 48 of the 54 eyes (89% despite prophylactic antibiotic drops. However only four eyes (7r4) had organisms isolated from the anterior chamber paracentesis taken at the end of surgery. Staphylococcus epidermidis was by far the most common organism isolated (881/0. Corynebacterium spp. were found in 14% of cases but Propionibacterium spp. were not specifically identified. Brain-heart infusion enrichment medium produced a marked increase in the yield of organisms isolated in comparison with the other culture media used. Despite the high degree of apparent bacterial contamination there were no cases of endophthalmitis. CONCLUSION: The results indicate that bacterial contamination of the surface of the eye is present during extracapsular cataract extraction and lens implantation in a large number of cases. However, the incidence of contamination of the anterior chamber at the end of surgery is very low and endophthalmitis remains a rare complication. The organism isolated is usually Staphylococcus epidermidis . Use of an enrichment medium is recommended to maximize the isolation of bacterial contaminants.