Abstract
Purpose: :
Non-inflammatory contact lens complications have been reported with higher modulus lenses. This study assessed the influence of lens modulus on comfort responses following lens insertion of ten marketed silicone hydrogel lenses.
Methods: :
Ten silicone hydrogel lenses (galyfilcon A [modulus 0.43], senofilcon A [0.72], narafilcon A [0.66], lotrafilcon A [1.4], lotrafilcon B [1.0], comfilcon A [0.75], enfilcon A [0.5], balafilcon A [0.91], asmofilcon A [1.1], filcon II 3 [0.5]) were fitted to 30 subjects over four scheduled visits. Lenses were randomly assigned and worn bilaterally on a daily wear basis for approximately two weeks. After each lens type was fitted, subjects were asked to rate their ocular comfort immediately following lens insertion and five minutes following lens insertion (5-min ocular comfort). Subjects wear also asked to rate edge awareness and lens awareness sensation. Ratings were measured on a 1 to 100 scale in 1-unit steps.
Results: :
Mean comfort response immediately after insertion ranged from 84.0 to 94.2. Post-hoc analysis showed a significant difference in comfort immediately after insertion between lotrafilcon A and senofilcon A (p=0.048) or enfilcon A (p=0.006). There were no significant differences for 5-minute ocular comfort, lens awareness or edge awareness. There was a significant negative correlation between mean comfort and lens modulus suggesting that as modulus increased there was a corresponding decrease in 5-min. ocular comfort (r=0.78) , edge awareness (r=0.69) and lens awareness (r=0.68).
Conclusions: :
A high lens modulus may adversely impact ocular comfort and sensations of edge or lens awareness. Further comparisons over the weekly/monthly wearing cycle are needed to confirm the influence of modulus on comfort with contact lens wear.
Clinical Trial: :
http://www.anzctr.org.au ACTRN12609000230257
Keywords: contact lens • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials