ACANTHAMOEBA-KERATITIS - RISK-FACTORS AND OUTCOME

Aims/Background-This study was initiated to investigate risk factors f or and outcome of Acanthamoeba keratitis. Methods-Results of treatment were studied in 22 patients (23 eyes) presenting to Bristol Eye Hospi tal between 1985 and February 1995. Details related to the use and dis infection of contact lenses were also obtained. An additional two pati ents who were seen at Bristol but mainly treated elsewhere were survey ed for contact lens related information only. Results-The incidence of Acanthamoeba keratitis rose substantially in the 1990s: three patient s presented before 1990, while the remaining 21 presented between Janu ary 1990 and February 1995. Eleven patients have presented since Janua ry 1994. All of the patients in this series were contact lens wearers, 16 (67%) using daily wear disposable contact lenses. Contact lens dis infection data were available in 22 patients of whom 11 (50%) were usi ng chlorine disinfectant. Other types of disinfection were much less c ommon. Four patients (18%) had not used any disinfectant. During the c ourse of the series the average diagnostic delay has fallen markedly, although in 77% of patients a diagnosis of a viral keratitis, most com monly herpes simplex, was made on first presentation. All but three of the series were treated with a combination of poly-hexamethylene bigu anide and propamidine isethionate. Penetrating keratoplasty was perfor med in 9/23 eyes (39%); in all of these eyes diagnosis was delayed for at least 6 weeks. All but one of the eyes in the series achieved a vi sual acuity of 6/9 or better after treatment, and 18 eyes (78%) saw 6/ 6 or better. Conclusions-Most patients with Acanthamoeba keratitis can now expect a good visual result and cure by medical therapy atone is favoured by early diagnosis.