Abstract
Abstract: :
Purpose: To compare the initial comfort response to a range of currently marketed soft contact lenses Methods: Fifteen subjects participated in a single blind study. Each of the following lenses was worn monocularly for a period of 10 minutes: PureVision TM (PV), Focus® Night & DayTM (ND), Focus® Dailies® (FD), 1 DAY ACUVUE® (AD) Proclear® (PC) together with Silsoft® (SE) as a positive control. Both the order of insertion and the wearing eye were chosen at random. Contralateral eyes remained without lenses throughout. Lenses were thoroughly rinsed with sterile saline prior to insertion. Standardised insertion technique was used and no more than 2 lens types were inserted in any one day. Subjects rated the subjective comfort of each lens relative to the control eye which was arbitrarily anchored at a value of 100. Ratings were obtained immediately after insertion, and after 1, 5 an 10 minutes of wear. Repeated measures ANOVA was applied. Results: There were no significant differences in comfort ratings between the ND, PV, AD, FD and PC lenses (p > 0.05). However, the SE lens was significantly less comfortable than the other lenses (p< 0.005). The comfort rating averaged across time was: FD:86± 11, PC:84± 13, ND:82± 11, PV:79± 12, AD:77± 16, SE:25± 20. The comfort ratings did not differ over time for any of the lens types (p=0.2). On average there was a 4 point (range 1 to 8 points) difference between insertion and 10 minute ratings. Conclusions: Under the conditions of this experiment initial comfort ratings do not differ for a range of soft contact lenses. This suggests that the perception of comfort during the first few moments of wear may depend on factors other than lens design or material characteristics..
Keywords: contact lens • clinical research methodology • cornea: basic science