NEW YORK, Feb 05 (Reuters) -- Decongestant eyedrops widely available without a prescription can be harmful to the eyes if used too frequently, according to a new study.
Overuse of the over-the-counter products may lead to sudden or recurrent conjunctivitis -- eye inflammation, redness, discomfort, and discharge -- which takes several weeks to clear up.
Eyedrops containing vasoconstrictors -- agents that narrow blood vessels -- seem to be the culprits, say ophthalmologists from Baylor College of Medicine in Houston.
The researchers say these agents, including naphazoline, tetrahydrozoline, or phenylephrine, are the principal active ingredient in popular eyedrops that are sold over-the-counter to alleviate redness and discomfort.
"The incidence of adverse reactions to ophthalmic decongestants is unknown," says Dr. Charles Soparkar and his Baylor colleagues. "Even if the incidence is low, the number of patients suffering reactions may be substantial because more than 15 million bottles of these eyedrops are sold each year in the United States."
The Houston eye researchers studied 70 people with unexplained conjunctivitis who had been using nonprescription eyedrops daily for an average of three years. It took between 1 and 24 weeks (4 weeks was the median) after they stopped using those eye products for their condition to improve.
But for some patients, the problem did not end there. "After their initial examination and treatment, two patients... returned years later with conjunctivitis resulting from the use of a different decongestant," the authors note.
In addition, three others developed recurrent eye symptoms when they used their eyedrops again.
These findings lead the authors to propose that some people may be prone to developing a sensitivity or allergy to decongestant eyedrops.
SOURCE: Archives of Ophthalmology (1997;115:34-38)
