Beware what lurks on the surface – persistent contamination of high-touch surfaces on slit lamps despite regular cleaning

Abstract

High-touch surfaces contributing to infection transmission are particularly concerning in the ophthalmology clinic where frequent contact exists between ophthalmologists and various ophthalmic instruments. Areas of surface contamination from an ophthalmologist’s contact with the slit lamp environment were identified using ultraviolet fluorescence as a surrogate for pathogen contamination. Ultraviolet fluorescent product was applied on the ophthalmologist’s hands after thorough hand washing to indicate the contamination that may be derived from multiple sources in the ophthalmology clinic, such as touching the patient or the patient’s folder during eye examinations and transfers. The ophthalmology clinic was run normally, with the ophthalmologist wiping down patient-contact surfaces on the slit lamp and performing thorough hand hygiene after every patient. Using ultraviolet black light, persistence of surface contamination in the slit lamp environment was identified and evaluated across five days. High-touch surfaces of suboptimal disinfection were inclined towards those touched only by the ophthalmologist, for example: joystick and chin-rest adjustment knob, as compared to patient-contact surfaces. Persistent contamination on the same surfaces revealed inefficacy of current hand hygiene and clinical disinfection practices. This poses a significant risk for pathogen transmission and underscores the importance of including these specific clinician high-touch surfaces in existing cleaning protocols.