A recent study suggests patients who wear scleral contact lenses to manage keratoconus could be at an increased risk of Acanthamoeba keratitis (AK) if they don’t follow the recommended wear and care instructions.

After three scleral lens wearers were diagnosed with AK, a team of Brazilian researchers sought to better understand the risk factors for infection in patients using this lens modality.

They found the main risk of infection was hypoxic changes in the corneal epithelium, caused by several scleral lens factors. The study specifically noted “the large diameter and minimal tear exchange, use of large amounts of saline solution necessary for scleral lens fitting, storing the scleral lens overnight in saline solution rather than contact lens multipurpose solutions, [and] not rubbing the contact lens during cleaning” were all associated with an increased risk of infection. In addition, the fluid reservoir may serve as an environment for Acanthamoeba multiplication.

The researchers recommend clinicians emphasize the importance of lens care in this patient population to reduce the risk of infection. Using single-use sterile saline, rubbing the lenses while cleaning them, cleaning the plunger and storing lenses in fresh multipurpose solution without topping off are all best practices the study found important.