Careless contact lens users ‘risk blindness’
A lax approach to cleaning contact lenses can result in a nasty eye infection that eventually causes blindness, warns a researcher from the University of London.
Dr Naveed Khan is investigating a parasite which has developed spines allowing it to cling on to the cornea despite the constant flushing of tears. The Acanthamoeba parasite then eats into the eye and causes severe damage and excruciating pain. Loss of an eye can even occur as a result of this particularly resistant bug.
The parasite is ubiquitous and crucially is found in tap water. This leaves those spurning appropriate cleaning solutions for ordinary tap water at particular risk.
About 0.01% of contact lens wearers are reportedly infected by the parasite every year, but Dr Khan believes the real rate of infection is much higher. He says misdiagnosis of the Acanthamoeba parasite is common in the UK, and globally, because of a lack of expertise in identifying this relatively new organism.
He says: ‘There has to be continued awareness about these emerging pathogens, which are causing serious infections and affecting human health and increasing burdens on our economy.’
More worryingly is the lack of treatment available for this infection, with only a couple of drugs available. Dr Khan adds: ‘Acanthamoeba is becoming resistant, so there is no effective treatment, it is simply a matter of trial and error. It’s very obvious that we have to find another approach.’
Dr Khan’s team at Birkbeck is investigating how the parasite wrecks such havoc on the eye, by growing an outer layer of cornea in the lab.
There are around 2.2 million people who wear contact lenses in England. This figure is likely to increase with the uptake of cosmetic lenses that allow wearers to temporarily change their eye colour.
