Bacterial contamination of anterior chamber during IOL surgery

To study the nature and frequency of bacterial contamination during cataract surgery.

The preoperative smears from the conjunctiva and anterior chamber (AC) fluid aspirates during extra-capsular cataract surgery (ECCE) with posterior chamber intraocular lens (PCIOL) implantation in 40 eyes were analysed for aerobic and anaerobic bacteria. Any change in the bacterial strains isolated before and after cataract surgery was also studied.

AC fluid aspirates were positive for bacteria in 15 eyes (37.5%). Coagulase-negative Staphylococcus was the most common aerobe (39.4%) and Propionibacterium acnes the most common anaerobe. Of the 15 cases with positive AC fluid cultures, 6 showed an organism in the AC aspirate different from the conjunctival smear.

Clinically there was no endophthalmitis in any of the eyes. Factors such as preoperative antibiotic use, the antibacterial properties of aqueous, or low inoculum size could explain this. The preoperative conjunctival smear may not be useful in predicting the AC fluid contamination or outcome of cataract surgery.