A parasite was eating my eyeball - Acanthamoeba

‘A parasite was eating my eyeball’ was a news item that appeared in the papers and online this week about the perils of contact lenses. A student, 19, had contracted an eye infection called Acanthamoeba. Which is caused when a parasite, common in tap water and soil infects the eye. Without treatment the infection can cause blindness so the poor lady in question had to administer drops to her eyes every hour for a week- hence she barely slept at all.

Acanthamoeba is a common parasite and thankfully rarely causes infection. It tends to strike contact lens wearers as if the lens is exposed to the parasite it is held on the eye all day, rather than being washed out as would be the case if we got water in our eyes when washing our face. Contact lens wearers who have a dry or scratched eye are also particularly susceptible to infection as the parasite can work its way into the cornea. Infection is pretty rare and infects around 2 in 100,000 contact lens wearers per year in the UK, which is around 20 times less than the number of daily wear soft contact lens wearers with bacterial infections.

If you are sensible with your contact lenses and follow this simple advice the risk of infection is very low. Here’s what you need to know:

Symptoms

• A red, (frequently) painful eye infection—especially if the discomfort does not improve with treatment.
• Foreign body sensation, tearing, light sensitivity, and blurred vision.
• Red, irritated eyes lasting for an unusually long period of time after removal of contact lenses.

Acanthamoeba can be hard to diagnose in the initial stages as it often resembles a bacterial infection. If you have symptoms or pain that persists you must always tell your optometrist immediately.

Risk Factors

• Use of tap water in cleaning and disinfecting contact lenses—including the lens case.
• Swimming with contact lenses in the eyes, especially in fresh water lakes and rivers. Acanthamoeba has also been isolated from virtually all water sources—from pools to hot tubs to showers.
• Failure to follow lens care instructions /poor compliance.

Lens Care Guide

• Always wash hands before handling contact lenses.
• Always clean and disinfect your lenses as instructed, after lens removal.  Contact lens solution must be discarded upon opening the case, and fresh solution used each time the lens is placed in the case. (If daily lenses throw away after removal – always insert a new pair of lenses).
• Contact lens solution must be discarded upon opening the case, and fresh solution used each time the lens is placed in the case.
• Lens cases can be a source of bacteria, after use they should be emptied, rinsed with fresh contact lens solutions and allowed to air dry. 
• If you wear replacement lenses (ie not daily disposable) Rub and rinse the surface of the contact lens before storing. Even if the solution you use says ‘no rub’ still give them a rub as this removes even more surface debris and dirt.
• Use only sterile products recommended by your optometrist to clean and disinfect your lenses. Saline solution and rewetting drops are not designed to disinfect lenses. Do not change your solution type without speaking to your eyecare practitioner first.
• NEVER use tap water to wash or store contact lenses.
• Avoid contaminating your lenses with make-up, aerosol sprays or wearing them near noxious fumes.
• Replace damaged, scratched or contaminated lenses immediately.
• Avoid long nails, which can harbour bacteria.  A scratched eye is vulnerable to infection.
• Replace lenses using your optometrist’s prescribed schedule. NEVER over wear your lenses.
• Do not sleep in contact lenses unless prescribed by your optometrist and never after swimming.
• Never swap lenses with someone else.
• Never put contact lenses in your mouth.
• Do not shower or swim in contact lenses. If you do, wear goggles and dispose of the lens immediately after getting out of the pool.  
• See your optometrist regularly for contact lens check ups. 6 monthly is recommended for regular wearers.

You should remove your lenses immediately if you experience any of the following:

• Itching, burning or stinging of the eye.
• A feeling of something in your eye.
• Excessive watering, unusual eye secretions or redness.
• Blurred vision, rainbows or haloes around objects.
• The lens feels less comfortable than it did when it was first inserted.

If the discomfort or problem stops when you take the lens out, inspect the lens for damage, dirt or a foreign body.  Discard the lens and insert a fresh one.

If the problem continues, remove the lenses and consult your eyecare practitioner immediately.

Prompt diagnosis and treatment is essential to avoid serious damage to your eyes.

REMEMBER – SYMPTOMS ARE WARNING SIGNS.  IF IN DOUBT TAKE THEM OUT.