Effect of Increased Power and Asphericity of Highly Aspherical Lenslets on Myopia Control Efficacy: A Contralateral Crossover Study.

PURPOSE: The study aims to evaluate whether the myopia control efficacy of spectacle lenses with Highly Aspherical Lenslet Target (H.A.L.T.) technology could be further improved by a combined increase of power and asphericity of lenslets.

METHODS

Fifty Singaporean myopic children aged 6 to 10 years were enrolled in a randomized, contralateral, crossover clinical trial. Two different myopia control spectacle lenses were tested: lenses with H.A.L.T. technology and lenses with maximized H.A.L.T. (H.A.L.T. MAX) technology. One group (N = 25) was assigned to wear H.A.L.T. MAX on the right eye and H.A.L.T. on the left eye, and the other group (N = 25) to wear the opposite combination for 6 months. The combinations were switched for the next 6 months. The primary outcome was the change in axial length (AL).

RESULTS

At baseline, mean (±SD) AL of eyes wearing H.A.L.T. and H.A.L.T. MAX lenses was 23.97 ± 0.84 and 23.99 ± 0.84 mm. After the first 6 months, mean (±SEM) axial elongation in eyes wearing H.A.L.T. and H.A.L.T. MAX lenses was 0.105 ± 0.016 and 0.043 ± 0.016 mm (P < 0.001), respectively. After the crossover, the corresponding mean AL change was 0.123 ± 0.014 and 0.077 ± 0.013 mm (P < 0.001). The differences in AL change between the two lenses were correlated with faster axial elongation with H.A.L.T. lenses in both phases.

CONCLUSIONS

Spectacle lenses with H.A.L.T. MAX technology slowed axial elongation more effectively than spectacle lenses with H.A.L.T. technology and might be particularly beneficial for children with faster axial elongation.

TRANSLATIONAL RELEVANCE: The relationship between the optical characteristics of lenslets and axial elongation offers a new avenue for developing more effective myopia control lenses.