A new study suggests a naturally-occurring material is an effective disinfectant for contact lenses, worn by millions of people worldwide. Microbial keratitis is one of the most serious potential complications for contact lens wearers. It’s an infection of the cornea that is caused by bacteria; the most common being Pseudomonas aeruginosa.
Previous studies have found that existing disinfecting solutions are not effective for preventing biofilm, which are clusters of bacteria that attach to the surface of lenses.
Hydroquinine, an organic compound found in the bark of some trees, is known to have bacterial killing activity against Pseudomonas aeruginosa and several other clinically important germs, including Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae.
The team behind the discovery, from the University of Portsmouth in England and Naresuan and Pibulsongkram Rajabhat universities in Thailand, has now explored the potential use of multipurpose formulas containing hydroquinine as a disinfectant for contact lenses.
They examined the antibacterial, anti-adhesion, and anti-biofilm properties of hydroquinine-formulated multi-purpose solutions (MPSs), and then compared it to two commercial MPSs; Opti-free Replenish and Q-eye. The natural compound killed 99.9 per cent of bacteria at the time of disinfection.
The paper, published in Antibiotics, says these findings may aid in the development of novel disinfectants aimed at combating the P. aeruginosa bacteria.
Dr Robert Baldock from the School of Pharmacy and Biomedical Sciences at the University of Portsmouth, said: “Commercially available disinfecting solutions, which are made up of a number of chemicals, can sometimes cause reactions with painful side-effects.
“We hoped to demonstrate that new agents made from natural products may be an excellent option to limit or reduce the risk of contact lens contamination.
“It is exciting to see how this research has progressed; from discovery to exploring potential applications.”
Hydroquinine is already known to be an effective agent against malaria in humans, and it is also being used in the Netherlands to treat nocturnal muscle cramps. Until now, there has been little investigation into its drug-resistant properties.
About being more sustainable? With awareness on plastic straws covered, it’s time to switch to recycling contact lenses. Some opticians in Canada have started accepting used lenses, a compounding problem if you wear dailies. If you can’t do that, put them in the garbage not down the drain. Some companies like LEXX offer recyclable packaging which is a start. And Acuvue lenses are made with renewable energy.
