The effect of silicone-hydrogel and conventional hydrogel contact lenses wear on the tear film: a comparison between de lenses

摘要

Purpose: The aim of this study was to evaluate the effect of one conventionalhydrogel and four silicone-hydrogel contactlenses of 6-months daily wear on the quantityand stability of the tear film. The tests wereperformed with a group of patients with noprevious contact lenses experience beforeand after wear on 96 eyes.Methods: The contact lenses tested were:19 Galyfilcon A (Acuvue® Advance™), 15Balafilcon A (PureVision™), 20 LotrafilconA (Focus® Night & Day™), 14 Lotrafilcon B(O2Optix™) and 28 Etalfilcon A (Acuvue®).Each silicone-hydrogel contact lens was usedfor 1 month and the conventional hydrogelfor 15 days. Every patient used a different lens in each eye. Tear film stability was monitored by tear Break-up-time (BUT) and Non Invasive Break Up Time (NiBUT) and tear volume was measured by the Total Tear Meniscus Height and the Red Phenol Test.Results: The following tables summarizethe difference between the measurementsobtained in the first and in the last dayof wear of each contact lens brand andthe results were analyzed comparing theconventional hydrogel and the siliconehydrogelcontact lenses (Table 1, 2, and 3), the lenses belonging to the first generation of silicone-hydrogel contact lenses (table 4) and the lenses belonging to the second generation of silicone-hydrogel (Table 5). The significance (p value) of 0.05 is considered statistically significant.Conclusions: Although there are some differences between the lenses, there are nostatistically significant differences betweenthe lenses and measurements obtained before and after contact lenses wear on thetear film tests.