Acanthamoeba keratitis is increasingly being diagnosed among people who wear thrapeutic and cosmetic contact lenses. The chain of events is thought to begin with contamination of the contact lens storage cases with Acanthamoeba from household or mains water supplies. If bacteria contamination is also present then these amoebas can multiply by ingesting the bacteria as a food source. If the contact lens is then immersed in the storage case and inadequately disinfected as Acanthamoeba can sometime adhere to it and so to the corneal epithelium and causes a severe and extremely painful keratitis which may be difficult to distinguish from other forms of keratitis.

The following diagnosis of Acanthamoeba keratitis using corneal biopsies and contact lens storage containers, PYG medium was used for harvesting the Acanthamoeba and was followed by DNA extraction.

The trophzoites adapted to axenic (bacteria free) growth in liquid media and characterized by restriction endonuclease digestion of whole-cell DNA to detect restriction fragment length polymorphisms (RFLPs) on agarose gel electrophoresis. This technique was used to study the relationship between morphologically identical strains of 20 isolates from corneal biopsies and one from contact lens storage container. DNA samples digested with EcoR1 and separated by agarose gel electrophoresis divided the strains into seven groups.