Effect of aspherical lens spectacles on axial length progression and refractive error in children with low to moderate myopia: a 24-month randomized controlled trial.

PURPOSE: To evaluate the efficacy of aspherical lens spectacles compared with single-vision spectacles in controlling axial length (AL) elongation and myopic progression in children with low-to-moderate myopia over 24 months.

METHODS

In this randomized, single-masked, controlled trial, 138 children aged 8-12 years with spherical equivalent refraction (SER) between -0.75 and -5.00 D and astigmatism ≤1.50 D were enrolled. Participants were randomly assigned 1:1 to receive either aspherical lens spectacles incorporating highly aspherical lenslets (HAL group, n = 69) or single-vision spectacles (SVS group, n = 69). Primary outcomes were changes in AL and cycloplegic SER at 24 months. Secondary outcomes included the proportion achieving near-emmetropic growth rate (defined as annual axial elongation <0.20 mm), changes at intermediate timepoints (6, 12, 18 months), adherence metrics, and safety assessments (adverse events, visual acuity, contrast sensitivity, basic stereopsis screening). Linear mixed models were employed for primary analyses under intention-to-treat principles.

RESULTS

Of 138 enrolled participants, 124 (89.86%) completed the 24-month follow-up. The HAL group demonstrated significantly less axial elongation compared with the SVS group (0.32 ± 0.18 mm vs 0.68 ± 0.22 mm, difference: -0.36 mm; 95% CI, -0.43 to -0.29 mm [P < 0.001]), representing 52.94% reduction. Myopic progression was -0.53 ± 0.38 D in the HAL group versus -1.21 ± 0.45 D in the SVS group (difference, 0.68 D; 95% CI, 0.54-0.82 D [P < 0.001]), indicating 56.20% reduction. Near-emmetropic growth rate was achieved in 44.93% of HAL participants versus 11.59% of controls (OR = 6.21; 95% CI, 2.58-14.95; P < 0.001).

CONCLUSIONS

Aspherical lens spectacles significantly reduced both axial elongation and myopic progression over 24 months compared with single-vision spectacles, with an excellent safety profile. These findings support aspherical lens technology as an effective option for pediatric myopia control.