Heading Out for a Swim? Remember to Remove Your Contact Lenses.

The microorganism Acanthamoeba, which can cause an extremely rare but potentially sight-threatening eye infection, has been identified in seawater at four NSW coastal sites.

Acanthamoeba has also previously been found in around one-third of the tap water in bathroom sinks in greater Sydney.

For contact lens wearers, this presents a concern because Acanthamoeba from the environment can get trapped between the contact lens and the eye, leading to infection known as Acanthamoeba keratitis (AK).

AK occurs when Acanthamoeba infects the cornea, the clear outer layer at the front of the eye. Acanthamoeba feeds on bacteria and corneal cells, leading to inflammation and damage to the cornea. Infection is difficult to eradicate due to the absence of drugs that can kill Acanthamoeba in both its cyst and trophozoite life stages. This can lead to vision loss, with around one-quarter of AK patients ending up with less than 25% of vision or becoming blind.

Contact Lenses: A Leading Risk Factor

Although rare, affecting an estimated 10–40 Australians per year, AK remains something to be mindful of.  The researchers from UNSW Sydney, University of Technology Sydney (UTS), and the University of the West of Scotland, found that wearing contact lenses is the leading risk factor, particularly when people mix their contact lenses with contaminated water.

This makes washing contact lenses in tap water, as well as showering and swimming with contact lenses in, major risk factors for the disease.

Published in Science of The Total Environment, the researchers concluded that contact lens wearers should not panic or avoid swimming altogether, but they should be careful to avoid developing AK. They should also monitor for early symptoms such as eye pain and redness, blurred vision, light sensitivity, and excessive tearing.

“For people planning to do water activities in these areas, it’s strictly advisable to take off your contact lenses before getting in the water,” said the study’s first author Binod Rayamajhee, who is completing a PhD focused on Acanthamoeba at UNSW Medicine & Health.

Permanent Vision Correction: A Safe Alternative

Laser vision correction is also an option that could free you from the need to wear contact lenses in and out of the water.

With over 20 years’ of experience as an ophthalmic surgeon, I have access to the latest laser vision correction technologies and can recommend the best option to suit your vision needs.  Following laser vision correction, you may even be able to dispense with your glasses or contact lenses altogether.

Please call on 02 8080 2180 to arrange a meeting.

Reference: Rayamajhee B., Williams N.L.R., Carnt N., Identification and quantification of Acanthamoeba spp. within seawater at four coastal lagoons on the east coast of Australia, Science of The Total Environment, Volume 901, 2023, 165862, ISSN 0048-9697. doi.org/10.1016/j.scitotenv.2023.165862.