An experimental study of the therapeutic effect of Nigella sativa aqueous extract and chitosan nanoparticles on Acanthamoeba keratitis

Abstract

Acanthamoeba is ubiquitous, existing in soil and water, potentially pathogenic free-living amoeba which occurs worldwide. It causes AK in immunocompetent and GAE in immunocompromised patients. AK is a painful vision-threatening corneal infection that can result from corneal trauma or the use of poorly maintained contact lenses. Contact lens wear is a major risk factor as the incidence of AK infection has increased markedly during the last 30 years due to increased number of contact lens wearers. Early diagnosis and treatment of AK are essential for improving the visual outcome of patients. Treatment of AK was achieved using a variety of drugs, but the development of toxicity and resistance hampered the continuous use of chemo-therapeutics. Thus, the increasing incidence of AK particularly among contact lens wearers necessitated the development of therapeutic agents active against the resistant cyst stage with high effectiveness and low toxicity.