Increasing incidence of Acanthamoeba keratitis in a large tertiary ophthalmology department from year 1994 to 2018.

Purpose: Acanthamoeba (AA) keratitis is a rare and severe infection with poor prognosis. The aim was to investigate the incidence and risk factors of AA keratitis in a large tertiary ophthalmology department in Denmark. Methods: A search was performed in our electronic patient records by the keywords: 'PHMB/polyhexanid', 'Brolene' or 'amoeba and chlorhexidine' from year 1994 to 2018, and afterwards medical records were reviewed. A total of 65 cases of AA keratitis were hereby identified. Results: Patients were relatively young, median (range) age of 38 (15–70) years. A significant increase of diagnosing AA keratitis occurred from 0.13 cases per million per year in the first 5 years to 2.7 cases per million per year the last 5 years. Eighty‐nine per cent of patients were contact lens users, and 49% had received corticosteroids before the diagnosis was established. Severe pain was present in 34% of patients. Prognosis was poor with final visual acuity of logMAR (mean, 95% CI) 0.30 (0.18–0.41), 18% had transplantation à chaud, and 2% were enucleated. Conclusion: The study indicates that the incidence of AA keratitis is increasing, also in Denmark. Most patients were young contact lens users. The course of the disease is long and often painful, and the prognosis is poor despite relevant treatment. [ABSTRACT FROM AUTHOR]