"Ocular comfort and symptoms in symptomatic contact lens wearers can be perceptibly improved by switching to an alternative contact lens-lens care product combination," write Daniel Tilia, BOptom (Hons), MOptom, of Brien Holden Vision Institute, Sydney, and colleagues. Their study provides scientific support for a clinical approach commonly recommended by eye care professionals.
The study included two groups of contact lens wearers: 24 patients who had discomfort related to their contact lenses at least part of the day-typically toward the end of the day-and 13 without symptoms. In random order, patients were assigned to use two different contact lens/lens care product combinations.
Based on previous studies, the combinations were ranked as providing the best (combination 1) and worst (combination 2) performance in terms of end-of-day comfort. Patients used each combination for eight days, without knowledge of which combination they were using. They then rated contact lens comfort and other symptoms during the two periods.
Patients with contact lens-related symptoms rated combination 1 more comfortable than combination 2. After eight hours of wear, the difference in ocular comfort (on a 10-point scale) was small but significant: 7.7 for combination 1 versus 7.1 for combination 2. Patients in the symptomatic group also rated combination 1 superior in reducing dry eyes and awareness of contact lenses in the eye.
In contrast, for patients who did not have symptoms before the study, there were no significant differences in ratings of the two combinations. For this asymptomatic group, scores were about the same with either the "most-comfortable" or "least-comfortable" combination.
Ocular discomfort is a common complaint among patients with contact lenses, and may contribute to the relatively low percentage of people wearing contact lenses for vision correction. "Properties of the lenses, organic deposits on worn lenses, and even the properties of the solutions used to clean lenses, are often blamed for this," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.
Eye care professionals will often switch the contact lens, type of lens care product, or both, in an attempt to improve comfort. However, it has been unclear how well this common approach works. "Clinicians and researchers are always trying to achieve comfort levels comparable to not wearing contact lenses," Dr Adams adds.
The new study was designed to evaluate the amount of improvement that might reasonably be expected by switching contact lenses and lens care products. The results indicate that "roughly half" of patients with contact lens-related symptoms have improved comfort by switching to a different lens/solution combination.
The study has been published in the May issue of Optometry and Vision Science.
--ANI (Posted on 02-05-2013)