Acanthamoeba keratitis is an eye infection caused by microscopic amoeba. Several species of Acanthamoeba have been found to infect humans. In addition to eye infection which usually affects the cornea, Acanthamoeba could cause skin lesion or a systemic infection. It may also cause granulomatous amoebic encephalitis (GAE), an infection of the brain and spinal cord that typically occurs in persons with a compromised immune system.
People with Acanthamoeba keratitis may have eye pain, eye redness, blurred vision, sensitivity to light, foreign body sensation in the eye and excessive tearing or other eye symptoms. Untreated infection can cause permanent visual impairment or blindness, which requires corneal transplantation to regain vision. Therefore, early diagnosis is essential for effective treatment of Acanthamoeba keratitis.
Mode of transmission
Acanthamoeba species are commonly found in the environment worldwide, especially in soil and dust, in fresh water sources such as lakes, rivers and hot springs, and in hot tubs, swimming pools and spa facilities. Besides, it can be found in heating, ventilating and air conditioning systems, sewage systems and fresh water system (shower head and taps). Acanthamoeba is also found in contact lens tools.
Acanthamoeba keratitis primarily affects otherwise healthy people, most of whom wear contact lens, particularly when users have poor lens hygiene or when lenses are worn during swimming or other aquatic activities. Also, persons who have abrasion or injury to the cornea are at increased risk of infection.
No known cases of person-to-person spread of Acanthamoeba keratitis have been reported so far.
The incubation period for Acanthamoeba keratitis is unknown.
Early diagnosis is essential for effective treatment of Acanthamoeba keratitis. If you have symptoms of Acanthamoeba keratitis, seek medical advice immediately.
To prevent contact lens related microbial keratitis, contact lens wearers are advised to:
NEVER wet your lens with saliva, bottled water or tap water.
NEVER wear your lens while sleeping, swimming or taking shower or beyond the recommended period.
The following important points on:
CLEAN & DISINFECTION
Clean and disinfect contact lens according to instructions from your eye care provider and the manufacturer's guidelines.
CARE OF LENS CASE
CARE OF LENS
To know more about contact lenses and tips on using contact lens solution, please refer to the following website: https://www.mdco.gov.hk/english/emp/emp_gp/emp_gp_selected_02.html