Keratoplasty in Contact Lens Related Acanthamoeba Keratitis

Acanthamoeba keratitis (AK) infection is a rather frequently occurring disease all over the world which can still cause serious or even total loss of vision despite improved diagnostic and therapeutic options. It may cause mostly keratitis, scleritis or chorioretinitis in people with competent immune systems. It mainly affects contact lens wearers with poor hygiene. Corneal trauma due to foreign body injury and exposure to contaminated water may also be associated with Acanthamoeba infection. Those with Acanthamoeba keratitis generally are immunocompetent. Nevertheless, these individuals do not develop protective immunity, and thus reinfection can occur. In the mid 1980s, an epidemic of Acanthamoeba keratitis occurred in the US which was attributed to increased contact lens use and poor lens hygiene. Conditions promoting the disease include not only poor contact lens hygiene but also the use of home-made saline solutions and corneal abrasions (Stehr-Green at al., 1989). In the United Kingdom, there was a marked rise in the number of cases in the first half of the 1990s, associated with the introduction and increasing popularity of disposable soft contact lenses shown to be due to irregular and/or chlorine based disinfection. After 1995 there was a decrease, perhaps resulting from an improvement in CL hygiene following the widespread dissemination of the results of a paper on Acanthamoeba keratitis as well as the gaining penetrance of new CL hygiene systems (Radford et al., 1995, 1998, 2002).