Review of Acanthamoeba keratitis associated with contact lenses in Hong Kong Chinese people

Aim: To review the management and outcomes of Acanthamoeba keratitis associated with contact lenses in Hong Kong Chinese people.Methods: This was a retrospective review performed at the subspecialty eye clinics at a tertiary hospital. Con- secutive patients with presumed Acanthamoeba keratitis who were treated at the Prince of Wales Hospital, Hong Kong, from August 2005 to August 2007 were included. Medical interventions included corneal scraping, confo- cal microscopy, and intensive anti-Acanthamoeba eye drops. Surgical intervention included corneal gluing. Risk factors, clinical features, culture results, confocal microscopy results, treatment responses, and visual outcomes were analyzed.Results: Nine eyes of seven patients with clinical Acanthamoeba keratitis were identified. The use of Complete® MoisturePlus™ solution, overnight contact lens wear, and swimming with contact lenses were found to be risk factors for Acanthamoeba keratitis. Ocular pain and perineural infiltrates were important clinical features of Acanthamoeba corneal ulcer. The culture-positive rate for Acanthamoeba was 22.2%. Confocal microscopy was positive for 44.4% of eyes. Eight (88.9%) of the treated eyes had improvement of vision after medical treatment. Eight eyes had vision better than 20/50 and 6 eyes had vision better than 20/30.Conclusions: Contact with contaminated fluids was an important risk factor for contact lens–related Acan- thamoeba keratitis. The recognition of clinical features, acquisition of corneal specimens for Acanthamoeba culture, and identification of intrastromal cysts by confocal microscopy were important for early diagnosis and subsequent treatment. Prompt initiation of a com- bination anti-Acanthamoeba treatment regimen was conducive to good visual recovery.