San Francisco-The effects of Systane lubricant eye drops (Alcon Laboratories) persist for about 3.5 weeks after the treatment is stopped, according to James McCulley, MD. At that time, the signs and symptoms of dry eye increase significantly compared with the baseline values when the patients were still being treated with the eye drops.
Recent research from Japan indicates that the first sign of dry eye may be blurred vision or a decrease in the quality and quantity of vision.
"This is becoming increasingly of interest to anterior segment surgeons," Dr. McCulley pointed out at the annual meeting of the American Society of Cataract and Refractive Surgery.
Twenty patients participated in the study. All patients had had keratoconjunctivitis sicca and were treated with Systane therapy alone once to several times daily (average number of instillations before the study, 2.1 times daily). After the patients were assessed, they were instructed to stop the treatment, Dr. McCulley said. He is professor and chairman, department of ophthalmology, The University of Texas Southwestern Medical School, Dallas.
Patients were evaluated weekly for 5 weeks using a scale from 1 to 4, where 1 indicated no symptoms and 4 indicated burning, dryness, grittiness, redness, crusty lashes, and stuck eyelids all of the time. The cornea and conjunctiva were stained at each visit and graded as well. Patients were permitted to discontinue the study whenever the signs and symptoms of dry eye returned to a level that caused them sufficient discomfort, Dr. McCulley said.
"It was remarkable that it took an average of 3.5 weeks for patients whose signs and symptoms had been controlled with Systane to have the signs and symptoms revert to the point that they decided to resume treatment," Dr. McCulley reported.
He expressed surprise at the length of time it took for the signs and symptoms to return.
"We know from our practices that it is easier to keep the ocular surface healthy in a patient who has dry eye than it is to make the surface healthy," he said. "The results of this study support our clinical impression.
"We found that when the patients decided to resume therapy, there was a significant increase in fluorescein staining of the cornea compared with baseline and a significant increase in conjunctival staining [p < 0.0001 for both comparisons]," he said. When the patients returned to therapy, they had a significant increase in burning, dryness, grittiness, and redness (p < 0.0001); there was less increase in crustiness and stickiness.
"The effects of treatment with Systane persisted after cessation of therapy for an average of 3.5 weeks," Dr. McCulley continued. "Systane is associated with a persistent beneficial effect on the ocular surface. In my hands, my frontline therapy for treating dry eye disease is Systane because it is effective."
In addition, he said that the dosing regimen with Systane is more likely to promote compliance.
"The patients can instill a drop four times a day-a dosing regimen that is tolerated much better by patients than instilling a drop every 1 or 2 hours-and still have very good results for the vast majority of patients," he concluded.