What is Acanthamoeba Keratitis
Acanthamoeba Keratitis, or AK, is a rare but serious rare disease involving the eye – the cornea, the clear window at the front of the eyes – that can result in partial vision loss or complete blindness.
AK is still considered a rare disease and is included in the Orphanet database (ORPHA67043) and with an estimated prevalence of 1–9/100,000. The numbers of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Contact lens wearers typically seek medical help late, because they are used to minor irritations in the eye. (1)
The rare disease is caused by microscopic free living amoeba (FLA) called Acanthamoeba that are commonly found in water sources and dust. Most types of Acanthamoeba are harmless to humans but can cause a serious infection if they come in contact with the cornea. If this is infected or damaged, it can extremely painful.
Those who wear contact lenses have a higher risk of exposure to the parasite. Improper lens hygiene, such as using tap water to wet the lenses or not cleaning or disposing the cases, can increase the probability of infection.
It is both difficult to diagnose and difficult to treat. So, if you wear contact lenses, have been in contact with water and are experiencing itchy, watery eyes, pain, sensitivity to light, redness, and/or blurred vision – PLEASE GO TO YOUR EYE DOCTOR IMMEDIATELY.
Figure: Acanthamoeba can enter the eye by attaching to contact lenses (1), the depleted immune activity allows binding to the epithelial layer (2) and the amoeba can begin to feed on the epithelial cells (3). Micro-abrasions on the epithelial layer provides an opportunity for the amoeba to access the Bowman’s membrane and stroma of the patient (4). Drug pressure can instigate encystation of the parasite (5) which can then begin reinfection upon removal of this pressure (6).
EACH CASE IS UNIQUE! so please don't think because you have Acanthamoeba Keratitis that your case is the worst and you might loss your vision forever or eye .. those are only extreme cases .. early diagnosed and treatment are you best possibilities.
Many AK warriors do recover their sight with time or after a cornea transplant. Your first priority (although we know it sounds unfair) is to focus on destroying all the acanthamoeba in your eye, once that is done, the doctors will focus in helping regain your vision.
Last but not least - YOU ARE NOT ALONE!!! there are many of us! Join a SUPPORT GROUP
Which is the life cycle of Acanthamoeba
Acanthamoeba has a life cycle of two modes:
The TROPHOZOITE stage is an active or alive & kicking mode
When the parasite feeds, grows and replicates itself, in this stage is when you might experience a lot pain, light sensitivity and/or sometimes decrease in vision.
The CYST stage is when is a dormant or sleeping mode
Does not show much activity, meaning when the parasite protects itself from attack by developing into a cyst or as I referred to it a house – forming a protective wall around itself which helps the amoeba to survive in conditions that are not favourable for survival, in other words they go in to hibernation being able to survive for long periods of time and unfortunately one cannot predict when they will become active.
Acanthamoeba are harmless to humans but can cause a serious infection if they come in contact with the cornea. If this is infected or damaged, it can be very painful...
Acanthamoeba Keratitis Extra Sources of Information
Practical online course: Managing Acanthamoeba Keratitis as an Ophthalmology Resident – by Nour Yanna Atassi MS and Alanna Nattis, DO, FAAO – CovalentCareers – (2020)