Abstract
Abstract: :
Purpose: Current dry eye treatments are primarily lubricant eye drops containing one or more recognized opthalmic demulcents. Many of these demulcents are polymers which may be prepared from a range of molecular weights at various concentrations, resulting in a specific viscosity. Viscosities of most common dry eye products have been either low (<10 cps) or very high (≷300 cps). Recently, a new mid-viscosity dry eye drop (60-90 cps) has been introduced, which has been formulated with a unique mixture of mid- and high-molecular weight carboxymethylcellulose (CMC). This study has investigated the clinical performance of this product. Methods: 103 subjects with mild to moderate dry eye were given either a low-viscosity 0.5% CMC artificial tear (Refresh Tears, Allergan) to use 4 times a day for 1 month. All subjects used a conventional artificial tear (Visine Tears, Pfizer) for 2 weeks prior to the study. Patients were assessed at days 7 and 30 for signs and symptoms of dry eye, including corneal and conjunctival staining and a standardized symptom survey. In a further study, 465 current users of a variety of artificial tear products were given either the mid-viscosity tear or one of several current low-viscosity tears, and surveyed for acceptability and preference over the preparation they used previously. Results: Both treatment groups (low- and mid-viscosity tears)experienced a significant reduction compared to baseline in staining and symptom scores at day 7 (p<0.001), and the mid-viscosity group experienced a further reduction in staining at day 30 (p<0.01). The acceptability and preference survey indicated that a large percentage of patients found the mid-viscosity tear no more blurring than low-viscosity tears in practical use, and that it generally required less frequent application than previously-used tear preparations. Conclusion: These clinical data indicate that a mid-viscosity 1% CMC artificial tear may have enhanced benefit for dry eye patients over conventional low-viscosity products, without compromising patient acceptability. The apparent dose-response of the CMC preparations with regard to staining suggests that CMC has a direct and protective effect on ocular surface integrity.
Keywords: 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 376 cornea: tears/tear film/dry eye