Over-the-counter eye drops - are they safe?
The ready availability of eye drops and antibiotic medication across the counter at pharmacies makes it an obvious first port of call for sufferers. After all, a short period of treatment clears up most cases of common eye discomfort - on the surface, at least.
However, while this approach can offer a simple short-term solution, it can easily lead to complications further down the line. Clinical trials have shown that eye drops bought across the counter have minimal long-term benefits.
Granted, they may ease the discomfort, but before self-medicating you should consider the potential side effects and the risk of lasting damage.
The best course of action is to consult an eye care professional for expert advice.
On a recent visit, a patient who came to me for an annual eye check-up complained about dry eyes. He asked me to recommend eye drops he could buy over the counter to lubricate and reduce bloodshot eyes.
I told him it wasn't a good idea to buy eye drops from pharmacies, because there have been reports of patients who used non-prescribed eye drops to ease discomfort suffering from glaucoma, cataract and other serious problems.
I had a patient, Miss Lau, who was an office worker. She wore contact lenses for a long period every day, causing dry, stinging and often bloodshot eyes.
To ease the conditions, she would use over-the-counter eye drops before putting in her contact lenses every day.
During the day while in the office Miss Lau would often use the eye drops to lubricate her eyes. The drops would be applied while she was still wearing the contact lenses.
One day she put in her contact lenses as usual, but felt a serious stinging sensation. She thought it was eye infection and came to see me.
After examination, I found that her corneas were not only infected, but she also had corneal ulcers with pus. I learned that the eye drops she had used contained steroids. She had also been using them incorrectly.
After treatment, the infection subsided, but the corneas remained scarred affecting her eyesight permanently.
In another case, Mr Yip, who enjoys playing video games, often played until he strained his eyes and his vision became blurred. When this happened, he would use eye drops to ease the discomfort.
Recently he found that even after applying the eye drops his vision remained blurred. He thought perhaps the dosage wasn't sufficient and increased the usage. A few weeks later he found that his vision would come and go unpredictably. He also became sensitive to light and had serious eye pain.
Upon initial examination, I found that his eye pressure was high, at 40mmHg. Normal intraocular pressure averages between 12 and 21mmHg.
I checked the eye drops he had been using and found that the medication contained steroids, which is often used to treat certain eye diseases and ease discomfort. But if used incorrectly, it can cause glaucoma, cataract and irreversible damage to the optic nerve. The optic nerve carries images of what the eye sees to the brain.
Yip had steroid-induced glaucoma and needed immediate treatment or it could have caused blindness.
These cases serve as a serious warning to people who buy eye drops over the counter to treat common discomforts such as red eyes, itchy eyes,dry eyes and blurred vision.
It's a convenient option, but many of these eye drops contain preservatives, steroids, angiotonics and antibiotics.
Most eye drops contain angiotonics, and after use your eyes will have a rapid contraction of blood vessels. Inadequate application without professional consultation could cause vision loss.
These eye drops will deliver short-term relief, but will not treat the cause. In the long-term they could cause irreversible damage to the eyes.
If you have problems with your eyes, you must consult an eye care professional for treatment.
Dr Jeff Hui is a Hong Kong-based ophthalmologist