Influence of wearing time on myopia control efficacy of spectacle lenses with aspherical lenslets

Abstract

Purpose : Within the MyCAL (Myopia Control with Aspherical Lenslets) clinical trial, to analyse the impact of wearing time on the myopia control efficacy of two spectacle lenses with aspherical lenslets, compared with single vision lenses (SVL).

Methods : In this prospective, randomized, double masked clinical trial, 170 children were randomized to wear either spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL) or control SVL. Daily wearing time of glasses was assessed over two years through 6-monthly questionnaires. Average wearing time over the full duration of the clinical trial in hours per day (WT) was used for analysis. Influence of WT on change of spherical equivalent of cycloplegic autorefraction (SER) and axial length (AL) were analysed for two WT categories: full-time wearers (at least 12 hours per day, every day) and part-time wearers (less than 12 hours per day or not every day) and through cumulative minimum WT.

Results : WT was analysed for the 157 children who completed all 6-monthly visits. For SVL, full- (n=34)/part-time (n=16) wearing did not impact change in SER (p=0.76) or AL (p=0.92). Myopia progression and axial elongation decreased with increasing minimum WT for HAL and SAL. For both HAL WT groups, SER and AL progression were significantly slower than for SVL (p<0.01). HAL full-time wearers (n=32) experienced significantly higher myopia control efficacy compared with SVL group for both SER (0.99±0.12D) and AL (0.41±0.05mm) than HAL part-time wearers (n=22, 0.54±0.15D, p=0.01; 0.26±0.07mm, p=0.03 respectively). For SAL, myopia control efficacy was comparable for full- (n=30, SER: 0.51±0.13D; AL: 0.23±0.06mm) and part-time wearers (n=23, SER: 0.31±0.15D, p=0.11; AL: 0.12±0.06mm, p=0.10).

Conclusions : Myopia control efficacy increased with wearing time for spectacle lenses with highly aspherical lenslets, reaching 0.99D less myopia progression and 0.41mm less axial elongation over two years for full-time wearers.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.