Acanthamoeba Keratitis: Are Recent Cases More Severe?

Purpose To identify a recent change in disease severity and visual outcomes of patients with Acanthamoeba keratitis (AK) at Wills Eye Hospital (WEH). Methods A retrospective chart review was performed of all cases diagnosed with AK at WEH between January 1, 2009, and December 31, 2015. Failure of treatment was defined as having a final best-corrected visual acuity worse than 20/100 and/or requiring keratoplasty. The patients were grouped into 2 outcome categories: successfully treated and those who failed treatment; and prognostic factors associated with failure status were evaluated. Additionally, patients who presented from 2009 to 2012 (labeled "first interval") were compared with those who presented more recently from 2013 to 2015 (labeled "second interval") to determine whether the treatment outcomes and patients' characteristics from the 2 intervals were different. Results Fifty-nine patients were diagnosed. The rate of treatment failure in the second interval was significantly higher than in the first interval (68% vs. 28%, P = 0.004). Compared with the patients in the first interval, those who presented in the second interval were significantly older, were treated with more corticosteroids before diagnosis, had more days from the symptom onset to initiation of AK treatment, and presented to WEH with poorer vision. Conclusions In recent years, the general profile of patients with AK has changed at WEH. Currently, we are treating older patients with more severe keratitis who are presenting later and with worse vision compared with our previous patients. At the same time, treatment outcomes have been poorer.