Background and Objectives: The aim of this study is the evaluation of bacterial contamination of Slit-lamps in Eye Centers of Farshchian Hospital and assessment of the current disinfectants on isolated bacteria from apparatuses.

Methods: In a cross-sectional study, 400 samples were collected from different parts of Slit-lamps (200 samples before and 200 samples after disinfection). The samples were cultured on Blood agar by sterile cotton swabs. A smear was also prepared for gram staining, then by differential and biochemical test identify and diagnosis microbial agents. The efficacy of two disinfectants (Sodium hypochlorite and Chlorohexidine) on Staphilococus epidermidis and Corynebacterium diphteroides by disk diffusion method were evaluated. Data was gathered through a questionnaire and analyzed by SPSS software (V:10) and T-test.

Results: The rate of slit-lamp's microbial contamination before and after disinfection was 87% and 42% respectively, that showed significant decrease after disinfection (p<0.001). The most frequent bacteria that isolated from apparatuses were Micrococi, Staphilococus epidermidis and Corynebacterium diphteroides. The disinfectants of Sodium hypochlorite in 90% and Chlorohexidine in 50% had strong efficacy on Staphilococus epidermidis, whereas for Corynebacterium diphteroides were 81/1% and 45/4%, respectively (P<0.05).

Conclusion: Our results showed that the ophtalmic biomicroscopy apparatuses )Slit-lamp( before disinfection have had the high rate of contamination, that have reduced in microbial clonization significantly, after disinfection (P<0.001). The efficacy of Sodium hypochlorite was stronger than Chlorohexidine.