Purpose:
To assess whether silicone–hydrogel (Si–Hy) lenses alleviate daily–wear end–of–day comfort issues.
Methods:
This investigation was a retrospective study of 334 individual wearing periods of at least one month involving 184 subjects and 11 separate trials including 6 different lens types (balafilcon A, etafilcon A, hioxyfilcon A, lotrafilcon B, omafilcon A, or polymacon) at a single site. Comfort was scored on visual analog scales (0–100) to a uniform protocol within 30 minutes of lens insertion from the blister pack and after at least one–month of wear, at the end of a designated replacement period, for measures of comfort, dryness and end–of–day (EOD) comfort.
Results:
Five different trials with etafilcon A yielded mean scores of 87.9, 89.1, 88.6, 88.9 and 89.4, demonstrating excellent repeatability. Mean scores for the three mid–water content hydrogels were higher than for the Si–Hy lenses across the comfort measures (see table). However, mean scores do not fully characterize the results; for example, lotrafilcon B had a relatively low mean and the lowest 10th percentile score but the highest median and highest 90th percentile scores for EOD comfort.
Conclusions:
The immediate interpretation is that Si–Hy lenses, at least those tested here, are not generally more comfortable than traditional hydrogels and can not be recommended for solving end–of–day dryness problems for all patients. Patient selection is crucial. It should be noted that most of our study sample were adapted to traditional hydrogels and Si–Hy lenses may develop greater comfort scores over longer wearing periods.
Keywords: contact lens • cornea: clinical science • clinical (human) or epidemiologic studies: outcomes/complications