Risk behaviors for infectious Keratitis among contact lens wearers in Switzerland: an analysis by contact lens type

BACKGROUND: To evaluate risk behaviors for infectious keratitis among contact lens (CL) wearers in Switzerland, focusing on survey-based, observational subgroup analyses by contact lens type. METHODS: This investigator-initiated, cross-sectional, survey-based, observational, multi-center study was conducted across five eye care institutions in Switzerland. Between August 2023 and August 2024, we interviewed participants wearing CLs using a structured questionnaire. We assigned four subgroups, which included daily disposable soft contact lenses (SCL), reusable SCL, rigid corneal contact lenses (RCL), and rigid scleral contact lenses (ScCL). The survey collected data on demographics, CL type and indication, self-assessed CL knowledge, and risk behaviors related to infectious keratitis. We classified risk behaviors into three main categories, including hand hygiene, wearing behavior, and exposure to water or saliva. RESULTS: 156 participants were included in the final analysis. Regarding the subgroup allocation, 38 of 156 (24.4%) wore daily disposable SCLs, 48 (30.8%) reusable SCLs, 40 (25.6%) RCLs, and 30 (19.2%) ScCLs. Overall, participants wearing rigid CLs felt better informed about CL care and demonstrated fewer risk behaviors than SCL users. However, risk behaviors were observed across all subgroups, including applying or removing lenses with potentially contaminated hands, extended CL wear, sleeping with CLs, and exposure to water or saliva. CONCLUSION: This study revealed variations in hygiene practices, wearing behavior, exposure to water or saliva, and risk perception across different CL types. Nevertheless, risk factors for infectious keratitis were present among all subgroups, underscoring the need for lens-specific patient education under professional supervision to improve compliance and mitigate complications.