Presumed late recurrence of Acanthamoeba keratitis exacerbated by exposure to topical corticosteroids

Abstract

A 28-year-old female with a history of contact lens wear presented with a 1 week history of pain and photophobia in her left eye. In vivo confocal microscopy (IVCM) and corneal scrape confirmed the diagnosis of Acanthamoeba keratitis (AK) which was treated with intensive topical propamidine isethionate (0.1%) and chlorhexidine (0.02%) with tapering dosage over 11 months. Five years after complete resolution of AK and cessation of all contact lens wear, the subject presented to her optometrist with a history of ocular discomfort and mild photophobia. Without further investigation she was prescribed topical corticosteroids. Three weeks later she presented with pain and reduced vision in the left eye. Slit-lamp examination revealed focal, inferior corneal stromal edema. IVCM confirmed widespread Acanthamoeba cysts. Treatment with topical polyhexamethylene biguanide (PHMB) 0.02% and propamidine isethionate 0.1% resulted in resolution of the AK. Despite an initially mild AK, this subject presumably retained viable Acanthamoeba cysts in her cornea 5 years after the initial episode. This report highlights the importance of caution when using corticosteroids in patients with a previous history of AK, even in the relatively distant past. Patients with AK should be warned regarding the risks of recurrence following presumed resolution.