Abstract
Purpose: :
To assess if the comfort and clinical performance of silicone hydrogel lenses used in conjunction with a hydrogen peroxide based system is worse when lenses were worn for four weeks compared to two weeks.
Methods: :
Ninety nine participants were randomised to wear either lotrafilcon B+copolymer 845 contact lenses or comfilcon A bilaterally for four weeks of daily wear . Both groups used hydrogen peroxide (ClearCare: CIBA VISION) as their lens care product. Participants were seen a total of three times in this study: Baseline, two weeks and four weeks.Both participant and practitioner were masked to the identity of the lens type.Clinical variables (physiological and lens characteristics) and subjective ratings (comfort and lens handling) were collected at all scheduled visits. Participants who attended both visits were included in this analysis. Mixed linear models were used for statistical analysis.
Results: :
There were no significant differences with any clinical variable at four weeks compared to two weeks.Equivalence at the 95% confidence level was demonstrated with clinical variables at four weeks compared to two weeks when clinical significance was set at a difference of ≥ 0.3 grade units on a scale of 0 to 4. Dryness at the end of the day was rated significantly better at four weeks (7.5±1.9, 7.3±2.0, p=0.043) compared to two weeks. There were no significant differences for any other subjective rating or visual acuity at four weeks compared to two weeks. Equivalence at the 95% confidence level was demonstrated with subjective ratings at four weeks compared to two weeks when clinical significance was set at a difference of ≥ 0.5 grade units on a scale of 1 to 10 with the exception of dryness at the end of the day (lower 95% confidence interval = 0.52) indicating improvement at 4 weeks.
Conclusions: :
These results indicate that comfort and clinical performance of these contact lenses are similar at four weeks compared to two weeks of lens wear.
Clinical Trial: :
www.anzctr.org.au 12608000329369