Pearls and Paradigms in the Management of Acanthamoeba Keratitis: A Review

Abstract

Abstract Acanthamoeba keratitis (AK) generally displays a protracted course with significant morbidity. This is partly due to the fact that it is often misdiagnosed as viral or fungal keratitis. It is associated most with contact lens (CL) wear in developed countries, and exposure to soil or unsanitary water in the developing countries. The textbook description of AK includes the presence of ring infiltration, radial keratoneuritis, and disproportionate pain. Of the patients that presented to our tertiary care center, only 40% had a history of CL use, and 33% had a ring infiltrate. Corneal scraping for microbiological culture on non-nutrient agar serves as the gold standard for diagnosis. Corneal biopsy and confocal microscopy hold diagnostic value in deeper lesions, and polymerase chain reaction and newer molecular techniques are emerging as rapid and effective tools. Biguanides are the drug of choice for AK. But it is important to reconstitute these drugs in correct dosages; otherwise, corneal toxicity can take place. The use of corticosteroids in AK is a matter of debate. We have used corticosteroids in cases with persistent keratitis, severe pain, and extra-corneal manifestations under the cover of amoebicidal therapy. Surgical intervention in the acute phase is reserved for advanced AK with limbus encroachment, perforations, or fulminant corneal abscesses. AK is thus a severe, potentially blinding disease, where a prompt diagnosis ensuring the timely commencement of amoebicidal therapy is an essential component of improving the patient’s prognosis. In this article, we have discussed the presentation, challenges in diagnosis and management, and our experience in managing AK.