There are many reasons for cleaning contact lenses correctly. As Professor Stephanie Watson explains here, using the recommended rub-and-rinse method can also remove coronavirus from the lens surface. Wash your hands well first
Written by Prof. Stephanie Watson BSc, MBBS, FRANZCO, PhD
Published in Eye Care Journal Scan / Research · June 09, 2022
Transmission of the coronavirus remains a concern, and understanding if contact lenses could expose the ocular surface to coronavirus is an interesting area for research, particularly as it has been reported that ocular exposure may be a potential route of coronavirus infection and hands and fingers can transmit coronavirus. Given that worldwide 175 million people wear contact lenses, knowledge from this paper may have important implications.
What did researchers in this publication do?
They looked at the binding of coronavirus variants (HCoV-229E and HCoV-OC43) to soft contact and rigid gas-permeable contact lens materials and then whether rub-and-rinse cleaning and contact lens disinfectants could remove coronavirus. To date, the rub-and-rinse cleaning step has been highly effective at removing bacteria, fungi, and acanthamoeba from contact lenses.
What did they find?
Saline rinsing reduces the levels of viral contamination from soft and rigid gas-permeable materials to below the limit of being able to measure. For etafilcon Q and lotrafilcon B contact lens materials, Clear Care (Alcon) and Cleadew (Ophtecs) reduced viral particles to below measurable levels. For Biotrue and OPTI-FREE Puremoist, rub-and-rinse cleaning was needed to reduce the viral particles to below measurable levels.
What does this mean for practice?
Eye care practitioners and patients can be reassured that contact lenses would be an unlikely source of coronavirus infection. Contact lens cleaning products containing hydrogen peroxide and povidine iodine can remove coronavirus. Rub-and-rinse, though, is important for nonoxidative systems.
How certain are these findings?
A small number of samples were included in the study, although the researchers did include a broad range of materials. Patients may also not conduct rub-and-rinse as effectively as the researchers. The authors also postulate that certain contact lens care products can change lens properties; this might affect viral adhesion.