Pathobiology and immunobiology of Acanthamoeba keratitis: Insights from animal models

Acanthamoeba keratitis (AK†) is a rare but sight-threatening disease caused by pathogenic species of Acanthamoeba. Despite its ubiquitous nature, the incidence of AK is relatively low compared to other forms of infectious keratitis. Although contact lens wear is a major risk factor, exposure to contaminated water and ocular trauma are also associated with AK. Once a patient develops AK the prognosis is very poor unless an aggressive treatment regimen is initiated early. Some of the intriguing features of AK are the lack of immunological memory, resistance of the dormant cyst form to treatment, differences between the pathogenic strains and soil isolates of Acanthamoeba and the unique role of the innate immune system in controlling this disease. Understanding the series of steps involved in the pathogenesis of the disease and the host immune response against Acanthamoeba antigens is crucial for developing effective therapeutic strategies targeting the disease.