Prescription Drops for Chronic Dry Eye

When the Eyes Don’t Have It

Here are a few possible adverse side effects listed in a magazine ad for a prescription drug:

• Temporary burning sensation
• Eye pain
• Itching
• Stinging
• Blurred vision

Nice, huh? And can you guess what the drug is? It’s Restasis – a medication that helps patients with chronic dry eye syndrome (DES) increase the ability to produce tears. And I expect that DES patients who put Restasis drops in their eyes and experience burning, stinging, and blurred vision probably have a strong desire to sit down and have a good cry – tears or no tears.

If you’re thinking, “There’s got to be a safer way,” you’re right. There is.

Keeping it artificial

Dry eye syndrome is most common among those who wear contact lenses, women during menopause, and patients who have undergone laser eye surgery. Older people may also experience DES because as we age our bodies produce less oil, which can throw off the precise balance of water, salt, proteins, mucus, and oil that coats and protects the surface of the eye. Chronic DES can damage the cornea and lead to vision loss.

Most over-the-counter “artificial tears” treatments for dry eye contain hyaluronic acid (HA), which has one key drawback: it doesn’t remain on the ocular surface very long. In a recent study, researchers from Italy’s University of Genoa tested HA against tamarind seed polysaccharide (TSP), extracted from tamarind tree seeds. TSP has a molecular structure much like mucus, which helps it stay longer on the surface of the eye.

STUDY PROFILE

• Researchers randomly assigned 30 subjects with DES to receive either TSP 0.5 percent, TSP 1 percent, or HA 0.2 percent at least three times daily for 90 days
• The TSP 1 percent applications worked better than HA in relieving ocular burning, ocular pain, blinking trouble, and sensation of foreign body
• None of the three groups reported blurred vision, ocular burning, or ocular itching when treatments were administered
• No overall adverse reactions were reported in any of the three groups

In their conclusions, the authors wrote: “This study highlights the need to expand this therapeutic agent to a wider dry eye population.”

TSP eye drops may be hard to find, but TSP is used as an ingredient in some commercial treatments.

Oil shortage

As I mentioned above, a reduction in natural oils produced by the body may play a role in dry eye syndrome.

In a 2005 study from Brigham and Women’s Hospital, dietary intake was assessed for more than 32,000 women between the ages of 45 and 84. About 1,500 of the subjects had been diagnosed with DES.

Analysis of the data showed that women who had the lowest intake of omega-3 fatty acids were 20 percent more likely to develop DES compared to women with the highest intake. Omega-3 from tuna provided the most effective prevention: Women who ate five or more tuna servings per week reduced DES risk by more than 65 percent compared to women who had only one serving of tuna per week.

If you have chronic dry eyes, talk to your doctor before using TSP eye drops or omega-3 supplements.

Sources:
“Establishing the Tolerability and performance of Tamarind Seed Polysaccharide (TSP) in Treating Dry Eye Syndrome: Results of a Clinical Study” BMC Ophthalmology, Vol. 7, No. 5, 3/29/07, biomedcentral.com
“Relation Between Dietary n-3 and n-6 Fatty Acids and Clinically Diagnosed Dry Eye Syndrome in Women” American Journal of Clinical Nutrition, Vol. 82, No. 4, October 2005, ajcn.org