[Microbial contamination of nipradiol with and without benzalkonium chloride].

PURPOSE

To compare microbial contamination of nipradiol both with and without benzalkonium chloride (BAC).

SUBJECTS AND METHODS

Twenty primary open angle glaucoma patients treated with nipradiol with BAC were studied. The nipradiol with BAC was switched to nipradiol without BAC. Four weeks after switching, the nipradiol without BAC was once again switched to nipradiol with BAC. The bottle caps, nozzles, filters, and solutions were cultured and examined for contamination.

RESULTS

In nipradiol without BAC microorganisms were isolated from caps (30%), nozzles (50%), solutions (0%), and filters (15%), whereas in nipradiol with BAC they were isolated from caps (35%), nozzles (40%), and solutions (25%). The microorganisms in the nipradiol without BAC were coagulase-negative Staphylococci (38.2%) and Propionibacterium acnes (29.4%), and in the nipradiol with BAC they were coagulase-negative Staphylococci (20.5%), Alcaligenes xylosoxidans (12.8%).

CONCLUSIONS

In nipradiol without BAC, the bacteria were detected outside the filters, but not in the solution. The rate of microbial contamination of the nipradiol without BAC was similar to that of the nipradiol with BAC. Both the bacteria detected from the nipradiol with and those detected in the solution without BAC consisted only of bacterial flora of the cul-de-sac and skin.