THE EFFECT OF INTRACAMERAL, PEROPERATIVE ANTIBIOTICS ON MICROBIAL-CONTAMINATION OF ANTERIOR-CHAMBER ASPIRATES DURING PHACOEMULSIFICATION

Purpose To assess the effect of per-operative antibiotics on contamina tion of anterior chamber (AC) aspirates during phacoemulsification. Me thods Two hundred and twenty patients undergoing phacoemulsification o f cataract were randomly allocated to receive an irrigation infusion f luid containing either balanced salt solution (BSS) alone or BSS with vancomycin (20 mg/l) and gentamicin (8 mg/l) during surgery. Conjuncti val swabs were obtained from all patients immediately before pre-opera tive preparation. At the end of surgery 20 mi of the AC aspirate was s ent for direct and enrichment cultures. Qualitative and quantitative m icrobiological studies were undertaken. The chi-squared test was used to compare differences between the two groups. Results There was no si gnificant difference between the positive culture rates of the conjunc tival swabs (28 vs 27; p>0.8). In the group that received BSS alone th ere were 22 (20%) positive AC aspirate cultures, 18 of which were from enrichment cultures. There were 3 positive (2.7%) cultures from the g roup that received antibiotics added to the BSS (p<0.0001). Conclusion The addition of gentamicin and vancomycin to the irrigation fluid dur ing phacoemulsification results in a highly significant reduction in t he microbial contamination of AC aspirates.