Effective disinfection of contact lenses is of paramount importance in the prevention of Acanthamoeba (AK). Therefore, this study was undertaken to evaluate the effectiveness of the multi-purpose contact lens disinfecting solutions against Acanthamoeba cysts of four isolates comprising two clinical isolates; HS 5, HTH 73, and two environmental isolates; TTA 1 and TKA 14. Five multi-purpose contact lens disinfecting solutions; Complete®, Renu® fresh™, RevitaLens OcuTec®, Opti-Free® Express® and Solo Care Aqua® were tested on cyst of the four Acanthamoeba isolates. The soaking times were based on manufactures recommendations (4 and 6 h), 8 h and 24 h. Each mixture of the cysts and disinfecting solution was transferred onto non-nutrient agar seeded with Escherichia coli. The agar plates were examined under inverted microscope daily until day 14 to detect the presence of Acanthamoeba trophozoites. All 5 multi-purpose contact lens disinfecting solutions tested were ineffective at killing all Acanthamoeba cyst isolates tested. This indicates that most multi-purpose contact lens disinfecting solutions do not have anti-Acanthamoeba activity necessary to prevent keratitis amongst the contact lens wearers.
Key words: Acanthamoeba; effectiveness; Malaysia; multi-purpose contact lens disinfecting solution