Myopia control using a modified optical defocus soft contact lens in schoolchildren-A 12-month randomised double...

Defocus Incorporated Soft Contact (DISC) lenses with +2.50 D myopic defocus reduced myopia progression by 25% in a previous randomised clinical trial (RCT). The current study aimed to evaluate if a stronger myopic defocus, +3.50 D with variable myopic defocus (DISC3.5plus), could slow myopia progression compared with single vision (SV) soft contact lenses in a 12-month RCT.

Conducted from December 2018 to January 2021, the current RCT randomly assigned myopic children to wear DISC3.5plus (n = 87) or SV (n = 80) lenses. Myopia progression and axial elongation were compared between the two groups. Analyses were performed for both enrolled and completed participants.

For all enrolled participants, the DISC3.5plus group had significantly less myopia progression (mean difference: -0.15 ± 0.07 D, p = 0.02) and axial elongation (mean difference: 0.04 ± 0.02 D, p = 0.04) than the SV group at 6 months but not at 12 months (myopia progression: p = 0.11; axial elongation: p = 0.13). For completed participants, the DISC3.5plus group (n = 33) had reduced myopia progression at both 6 months (0.25 ± 0.07 D, p = 0.001) and 12 months (0.19 ± 0.09 D, p = 0.049) compared with the SV group (n = 40), but not in axial elongation (6 months: p = 0.16; 12 months: p = 0.32). In January 2020, the coronavirus pandemic disturbed contact lens-wearing patterns.

DISC3.5plus lenses significantly slowed myopia progression and axial elongation compared with SV lenses for all enrolled participants over 6 months. The pandemic hindered longer term efficacy follow-up and sample size; thus, further investigation with more participants is needed to confirm sustained treatment effects.