Spectacles With Highly Aspherical Lenslets Slow Myopia
By Lynda Seminara
Selected by Richard K. Parrish II, MD
Journal Highlights
American Journal of Ophthalmology, March 2023
Download PDF
Slowing myopia progression is crucial to reduce the global burden of this disorder. Optical strategies that not only correct refractive error at the fovea but also modulate defocus at the peripheral retina can slow the progression of myopia. Various types of spectacle lenses have been designed for this purpose. Sankaridurg et al. conducted a randomized, controlled, double-masked, crossover study to compare the progression-slowing capability of lenses equipped with highly aspherical lenslets (HAL) with that of standard single-vision devices (SV; controls). The results showed that HAL is superior to SV.
Altogether, 119 Vietnamese children participated in this study (age range, 7-13 years). Their spherical equivalent (SE) refractive error ranged from –.75 to –4.75 D. The participants were assigned randomly to wear HAL or SV initially. After six months (stage 1), they were switched to the other device for the next six months (stage 2). At the end of stage 2, both groups wore HAL for six additional months (stage 3). The groups were identified by the sequence of lens wear. Group 1 was designated as HSH (HAL-SV-HAL) and group 2 as SHH (SV-HAL-HAL). The main outcome measures were 1) the differences between HAL and SV in change (Δ) for SE and axial length (AL) during each stage and 2) the comparison of ΔSE/AL with SV between the HSH and SHH groups to explore the possibility of myopia rebound after the switch.
During stages 1 and 2, the progression of myopia was significantly slower with HAL than with SV (stage 1 SEΔ: –.21 vs. –.27 D, p = .317; stage 2 SEΔ: –.05 vs. –.32 D, p < .001; stage 1 ALΔ: .07 vs. .14 mm, p = .004; stage 2 ALΔ: .04 vs. .17 mm, p < .001). For ΔSE/AL with SV, there was no significant difference between the study groups. The average daily wear time was 14 hours for both types of lenses. The children were compliant with lens wear, and there was no indication of rebound after the switch from HAL to SV. No lens-related adverse event occurred with either lens at any stage of the study.
“The strength of the study was the double-blind, crossover nature,” said the authors, which allowed all participants to experience each type of lens for at least six months. They acknowledged that longer studies are needed to determine the risk of rebound.
The original article can be found here.