The effectiveness of a three-step sterilization method for Goldmann tonometer prism: A cross-sectional study

PURPOSE: To propose a three-step sterilization method for Goldmann tonometer prism (GTP) and to analyze the sterilization effects of each step. METHODS: 120 patients (240 eyes) who underwent Goldmann applanation tonometer (GAT) IOP measurement were enrolled in this study. GTPs were used individually for each patient and wiped by swabs soaked with 75% ethyl alcohol, ofloxacin eye drops, and 75% ethyl alcohol for at least 5 s. GTPs were directly pressed onto the surface of agar plates before (W0) and after three-step sterilization (W1, W2, and W3). All the agars were sent to the laboratory in 2 h and incubated at 37°C for 48 h. Subsequently, the growth of microbial species was assessed through visual inspection of the colonies at the inoculation points on the agar surface. RESULTS: Staphylococcus. epidermidis was the most frequently isolated bacterium and was observed in 23.33% of all prisms. Most of the bacteria were eliminated at W3 except Staphylococcus. epidermidis and Kocuria roseus in one case. The isolation rates of Staphylococcus genus and Staphylococcus. epidermidis were significantly decreased (both with P < 0.001). The number of bacteria types isolated from prisms at time point W2 and W3 had a statistically significant difference compared with W1 and W (both with P < 0.05), while W2 and W3 exhibited no significant difference. CONCLUSION: This three-step sterilization method for GTP proved to be effective and safe for repeated use. We recommend using ofloxacin to prevent the transmission of pathogens based on ethyl alcohol, which could also bring some economic benefits.