Evaluation of Three Different Methods to Establish Animal Models of Acanthamoeba Keratitis

Abstract

PurposeTo produce animal models of Acanthamoeba keratitis and to evaluate the advantages and adaptation range of each of the three methods employed.Materials and MethodsMice and Wistar rats in three groups of 15 rats and 15 mice each were used to establish the models. Right corneas in group A were scratched and challenged with Acanthamoeba. Those in group B were scratched and covered with contact lenses incubated with Acanthamoeba. Those in group C received an intrastromal injection of Acanthamoeba. Five rats and 5 mice in each group were used for histopathological investigations and the other 10 in each group were used for clinical evaluation. The models were evaluated by slit lamp examination, microscopic examination and culture of corneal scrapings, HE staining of corneal sections, and pathological scoring of the infections.ResultsFour rats and 6 mice in group A, 7 rats and 8 mice in group B, and 10 rats and 10 mice in group C developed typical Acanthamoeba keratitis.ConclusionCorneal scratching alone has the lowest infection rate, while scratching and then covering with contaminated contact lenses has a moderate rate of infection and most closely mimics what happens in most human infections. Intrastromal injection of Acanthamoeba gives a much higher infection rate and more severe Acanthamoeba keratitis.