[Acanthamoeba keratitis]

ABSTRACT

Prognosis for Acanthamoeba is worse than for many other types of infectious keratitis. Treatment is difficult especially in advanced stages and it may result in permanent visual impairment or blindness. However, especially if caught early, satisfactory outcomes can certainly be achieved. The purpose was to evaluate the clinical features in five patients diagnosed in our department between 2007 and 2011. Risk factors, clinical diagnosis and therapeutic characteristics were studied retrospectively in this study. All patients were referred in a second or third intention. These are three women and two men with a mean age of 38.5 years admitted for corneal abcess in 3 cases and pseudendritic keratitis in 2 others. The risk factors found were contact lens wear in 2 cases, contact with contaminated water in 2 cases and the laboratory tests revealed an unrecognized diabetes in a case. Corneal sampling allowed the isolation of Acanthamoeba in 3 cases and in two cases the diagnosis was made by Polymerase Chain Reaction. All patients received broad-spectrum antibiotics and Hexamidine. ketoconazole was associated in 3 cases and Polyhexamethylene biguanide [PHMB] in 1 case. Evolution was marked by panophthalmitis and eyeball phthysis in 1 case, corneal opacity with neovascularization in two cases justifying a corneal graft. Regression with ad integrum recovery was observed in 2 cases of epithelial keratitis. The incidence of Acanthamoeba keratitis varies from one country to another between 0.15 and 1.4 per million inhabitants. Acanthamoeba are naturally occurring amoeba [tiny, one-celled animals] commonly found in water sources, such as tap water, well water, hot tubs, and soil and sewage systems. Contact lenses are still responsible for the majority of cases [2 cases] despite knowledge of this now well-established major risk factor and its preventive measures including strict hygiene for the maintenance of contact lenses. Medical treatment is very disappointing in advanced forms [3 cases]. The dramatic consequences of this complication justify a systematic treatment against amoeba in each case of suspected diagnosis. Acanthamoeba keratitis is a serious vision-threatening disease. Early diagnosis and treatment are essential for improving visual outcome: