Abstract
Purpose: :
To review the clinical presentations, risk factors, medical and surgical management, and outcomes of patients with acanthamoeba keratitis (AK).
Methods: :
Retrospective review of medical records of all patients suspected for having AK from January 1999 through May 2008 at Cole Eye Institute.
Results: :
Thirty-one eyes of 28 patients were identified as having either culture- or tissue-proven AK or presumed AK based on clinical exam and complete response to full course of treatment. The mean age was 35.5 years (range 13-61). 68% were female. Mean follow-up was 22.1 months (range 0-72). Risk factors identified for AK were exposure to contaminated water (25.8%), poor CL hygiene (16.1%), overnight wear of CL (12.9%), and history of trauma (3.2%). 74.2% of eyes presented with pain. The average duration of symptoms prior to diagnosis was 6.7 weeks (range 0-36). 42% were treated for herpes simplex keratitis prior to diagnosis of AK. 71% were treated with steroids prior to diagnosis. Clinical presentations included early AK: epithelial disease only in 29% of eyes or perineuritis in 19.4% of eyes, or late AK: stromal disease with or without epithelial disease in 71% of eyes or ring infiltrate in 32.3% of eyes. Most eyes were treated with 3-drop combination of topical polyhexamethylene biguanide, propamidine, neomycin, or chlorhexidine. Oral itraconazole was given in 65.5% of cases. Mean duration of topical treatment was 7.5 months (range 0.3-22). All 7 early AK cases had best corrected visual acuity of 20/30 or better at last follow-up. 63.6% of late AK cases achieved 20/30 or better. Complications from AK (cataract, glaucoma) were observed in 20.7% of patients. Eight of 29 eyes underwent surgical intervention, all of which were for visual rehabilitation. Five patients had recurrences of AK. One patient demonstrated viable cysts in the corneal button, despite 15 months of maximum medical treatment and 5 months off all medical treatment.
Conclusions: :
The most common risk factor for AK continues to be CL wear. AK requires prolonged and intense treatment, although good final visual acuity can be achieved. Viable acanthamoeba cysts can still persist in a non-inflamed cornea after extensive medical therapy.
Keywords: Acanthamoeba • cornea: clinical science • bacterial disease