The Parasitic Ulcer Treatment Trial (PUTT) is a multi-center, parallel-group, randomized clinical trial. The purpose of this study is to determine whether including topical corticosteroids in a regimen for acanthamoeba keratitis (AK) will improve vision. Patients presenting to all enrollment centers with evidence of acanthamoeba keratitis will be eligible for the trial if there is evidence of ocular inflammation after 4 weeks of anti-amoebic therapy. Those who agree to participate will be randomized to one of two treatment groups:

• Group 1: Topical corticosteroid
• Group 2: Topical placebo

Inclusion Criteria:

• AK on at least one of the following: culture, smear, PCR, shotgun sequencing, biopsy, or confocal microscopy
• Ocular inflammation after 1 month of anti-amoebic treatment, defined as conjunctival, corneal, episcleral, or anterior chamber inflammation

Exclusion Criteria:

• Evidence or history of interstitial keratitis
• Known herpetic keratitis, as determined from history, exam, or microbiological testing
• Known fungal keratitis, as demonstrated from corneal scrapings
• Corneal perforation or impending corneal perforation
• Prior therapeutic keratoplasty for acanthamoeba keratitis
• Unwillingness or inability to follow-up
• No light perception in the affected eye
• Known hypertensive response to steroids
• Corticosteroid allergy
• Concurrent treatment with systemic corticosteroids
• Concurrent granulomatous amoebic encephalitis

IPD available on request.

After publication of the main results

Request by email addressed to principal investigator.