Combined effect of comfort and adverse events on contact lens performance

To report the performance of various contact lenses and lens care solution combinations based on the combined response of subjective comfort and adverse events (AEs).

A retrospective analysis of 28 lens/solution combinations each tested on approximately 40 participants who wore their assigned combination on a daily wear basis and were followed for a 3-month period, with visits at baseline, 2 weeks, and 1 and 3 months. Lenses included frequent replacement and daily disposables. Solutions included hydrogen peroxide and multipurpose types. Subjective comfort (scale of 1 to 10) and AEs were collected and reported as a group mean and percentage, respectively. The data were converted into a ratio between 0 and 1 to represent the relative performance within the combination series, with a higher ratio indicating better performance in both AE rates and comfort.

The overall AE rate was 3.6 events per 100 participant-months (95% confidence interval [95% CI], 2.7 to 4.7%). The rate was found to be lower in daily disposables compared with that in daily wear lenses (3.1 vs. 10.9%, p < 0.001). The overall comfort on insertion rating was 8.3 (95% CI, 8.1 to 8.4), and comfort at end of day was 7.2 (95% CI, 7.0 to 7.4). Based on the 28 lens/solution combinations, there was no significant correlation between overall AE rates and comfort on insertion or at end of day (Pearson correlation, -0.34, p = 0.08; and Pearson correlation, -0.23, p = 0.25, respectively). Less than 18% of the combinations tested combined good comfort with low AE rates.

Both subjective comfort responses and AE rates varied according to the combination of lens type and care system in use. The combinations with the best comfort ratings did not necessarily have a favorable AE rate. Practitioners can maximize behavior with respect to both these factors by choosing an appropriate care system for the lenses they prescribe.