PURPOSE: To produce animal models of Acanthamoeba keratitis and to evaluate the advantages and adaptation range of each of the three methods employed. MATERIALS AND METHODS: Mice 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. RESULTS: Four 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. CONCLUSION: Corneal 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.
Acanthamoeba/growth & development ; Acanthamoeba Keratitis/*parasitology/pathology ; Animals ; Contact Lenses/adverse effects/parasitology ; Cornea/parasitology/pathology ; Disease Models, Animal ; Female ; Male ; Mice ; Microscopy ; Rats ; Rats, Wistar

In an effort to characterize, on the molecular scale, the Acanthamoeba initially isolated from the cornea of an amoebic keratitis patient associated with overnight-wear orthokeratology lens in Korea, we conducted mitochondrial DNA restriction fragment length polymorphism, 18S rDNA sequencing, and drug sensitivity analyses on the isolate (KA/PE1). The patient was treated with polyhexamethylene biguanide, chlorhexidine and oral itraconazole, which resulted in resolution of the patient's ocular inflammation. The majority of the molecular characteristics of the KA/PE1 were determined to be identical, or quite similar, to those of A. castellanii Ma strain, which had been isolated also from amoebic keratitis. The risk of Acanthamoeba keratitis as a potential complication of overnight orthokeratology is briefly discussed.
*Sequence Analysis, DNA ; RNA, Ribosomal, 18S/genetics ; Polymorphism, Restriction Fragment Length ; Parasitic Sensitivity Tests ; Myopia/therapy ; Itraconazole/administration & dosage ; Humans ; Female ; Disinfectants/administration & dosage ; DNA, Ribosomal/analysis ; DNA, Protozoan/analysis ; DNA, Mitochondrial/analysis ; Contact Lenses/*adverse effects ; Chlorhexidine/administration & dosage ; Biguanides/administration & dosage ; Astigmatism/therapy ; Antiprotozoal Agents/administration & dosage ; Animals ; Adolescent ; Acanthamoeba Keratitis/drug therapy/*parasitology ; Acanthamoeba/classification/*genetics/*isolation & purification