Contact lenses - a “no water” sticker to avoid water-related corneal infections

A study conducted at Australia’s University of New South Wales has determined the effect of a ‘no water’ lens case sticker on patient behaviour and storage case contamination. Indeed, the frequent use of water-related imagery in marketing material to indicate freedom from dryness encourages well established risk factors for corneal infection, particularly Acanthamoeba keratitis.

The 18-month trial randomised 200 daily lens wearers to either receive a storage case with a ‘no water’ sticker (test) or without the sticker (control). Both groups received written compliance information and participants completed a self-administered lens hygiene questionnaire at baseline and after six weeks.

After six weeks, the research team found the overall water exposure score and endotoxin levels reduced significantly in the test group compared with the control group.

UNSW Scientia research fellow and senior lecturer Dr Nicole Carnt, who led the trial along with Professor Fiona Stapleton, Dr Jacqueline Tan, and Ms Memoona Arshad, a UNSW School of Optometry and Vision Science PhD candidate, said the findings challenge a preconception among some practitioners that many contact lens wearers are unwilling to adapt their behaviours.

She also said there is a view that because diseases such as Acanthamoeba keratitis are rare, they are not worthy of heightened awareness – and wearers will refrain from wearing contact lenses if they are aware of it. Yet exposure of contact lenses to contaminated water during showering or swimming without goggles increases the risk of contact lens-related disease.

“I find that people who suffer from Acanthamoeba keratitis have a real sense of injustice and wonder why this information wasn’t given to them. They also want to tell other people to prevent it happening to them,” Carnt added. “The “no water” sticker is a visual reminder for patients not to use water with contact lenses. We want to stress that it is important for people to wash their hands but they need to dry them as well. A lot of the time people think ‘well, we drink water and wash our face with it, so it must be sterile’, but microorganisms that are in it can have a devastating impact on the eye.”