Clinicians evaluating contact lens users with symptoms of eye pain or redness, tearing, decreased visual acuity, discharge, sensitivity to light, or foreign body sensation should consider Acanthamoeba Keratitis and refer the patient to an ophthalmologist, if appropriate. Early diagnosis can greatly improve treatment efficacy.
Diagnosis of Acanthamoeba keratitis requires a high degree of suspicion, especially in a contact lens wearer with a recent diagnosis of another form of keratitis, such as herpes simplex virus keratitis, who is not responding to therapy. Diagnosis of AK is based on clinical presentation and isolation of organisms from corneal culture or detection of trophozoites and/or cysts on histopathology. However, a negative culture does not necessarily rule out Acanthamoeba infection. Confocal microscopy and polymerase chain reaction assays to detect Acanthamoeba can also assist with diagnosis. Clinicians should consider obtaining clinical specimens (e.g., corneal scrapings) for culture before initiating treatment.