Clinical performance of daily disposable soft contact lenses using sustained release technology

Abstract

Purpose Polyvinyl alcohol (PVA) is a successful tear film stabiliser and is widely used in comfort drops and some soft contact lens materials. A PVA-containing lens, nelfilcon A has been modified to include additional (non-functional) PVA in order to provide improved comfort. This study aims to examine the clinical performance of this nelfilcon A lens with AquaRelease™ (AquaRelease). Methods Two contralateral, investigator masked, open label, subjective and objective evaluations were conducted. The first examined the effect of adding increased molecular weight PVA to nelfilcon A ( n = 5), and the second compared this AquaRelease lens to ocufilcon B ( n = 34). The principal measures were non-invasive break-up time (NIBUT) and subjective comfort, which were assessed at the beginning and end of a week of daily wear, and three times throughout 1 day at 8, 12 and 16 h. Results All subjects successfully completed the daily wearing schedule of 16 h. On initial insertion, subjective comfort and NIBUT improved for AquaRelease than original nelfilcon A lenses ( p < 0.05). Initial comfort was better for AquaRelease compared to ocufilcon B lenses ( p = 0.01); however, NIBUT was not statistically different (11.7 ± 15.6 s versus 8.4 ± 6.8 s; p = 0.26). Subjective comfort decreased with time ( p < 0.001), but there was no significant difference between AquaRelease and ocufilcon B lenses ( p = 0.16). NIBUT was not significantly affected by time ( p = 0.56) or between lenses ( p = 0.33). At the end of a weeks’ wear, subjective initial, end-of-day, overall comfort and vision were rated significantly better with AquaRelease than ocufilcon B ( p < 0.01). Conclusions Release of additional non-functionalised PVA from the nelfilcon A lenses appears to enhance comfortable contact lens wear.