[Factors which affect the progression and severity of Acanthamoeba keratitis].

To detect factors which affect the severity of Acanthamoeba keratitis. Patients diagnosed as having Acanthamoheba keratitis in our hospital from 2005 to 2009 were divided into two groups according to the severity, i.e., mild and severe. The days needed for the diagnosis, age, sex and the application of topical steroids were analyzed in each group. Forty-four eyes of 41 patients were involved; 33 eyes were diagnosed as mild and 11 eyes as severe types of Acanthamoeba keratitis. The average number of days from the initial symptoms was 19.8 in the mild and 15.1 in the severe type, and the average ages were 25.2 and 40.4 respectively. Topical steroids before the diagnosis of Acanthamoeba keratitis were applied in 72.7% of the severe cases and in 36.4% of the mild cases. The severity of Acanthamoeba keratitis was not directly related to the period from the initial symptoms, instead, some patients showed a rapid progression. Older age and the application of topical steroids before the diagnosis should be considered in rapidly progressive Acanthamoeba keratitis.