AIM: To learn about the current condition about bacteria contamination of aqueous humor during cataract operation.

METHODS: Bacterial culture was conducted of the samples of aqueous humor and conjunctival sac collected from 807 patients during cataract operation from December 2010 to December 2012. Then, the bacterial culture results were analyzed.

RESULTS: On average, the bacterial culture positive rate was 0.93%, with no significant difference in the positive rates of samples collected at different times. The average bacterial culture positive rate of conjunctival sac was 9.54%, with significant difference between the positive rates before and after the operation(χ²=37.21, P<0.01). Most of the bacteria types in aqueous humor were the same as those in the conjunctival sac, with most frequent strain being staphylococcus epidermidis(60.00% for aqueous humor and 91.56% for the conjunctival sac). During continuous operations, >6 times of patients' aqueous humor and the positive rate of conjunctival sac bacteria culture is significantly greater than that of ≤5 times of patients. The result of the drug sensitive test indicated that most bacteria in aqueous humor and conjunctival sac were sensitive to Cephalosporins while they were highly resistant to penicillin, erythromycin, tetracycline, and Lomefloxacin.

CONCLUSION:Because of the bacterial pollution in the water from most of the conjunctival sac, preoperative conjunctival sac aseptic preparation is essential. Because intraoperative conjunctival sac, even real water may have some bacteria, strengthen the local application of antibiotics can effectively prevent postoperative intraocular infection.