One-year myopia control efficacy of spectacle lenses with aspherical lenslets

Abstract

Aims: To evaluate the 1-year efficacy of two new myopia control spectacle lenses with lenslets of different asphericity.

Methods: One hundred seventy schoolchildren aged 8-13 years with myopia of -0.75 D to -4.75 D were randomised to receive spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL), or single-vision spectacle lenses (SVL). Cycloplegic autorefraction (spherical equivalent refraction (SER)), axial length (AL) and best-corrected visual acuity (BCVA) were measured at baseline and 6-month intervals. Adaptation and compliance questionnaires were administered during all visits.

Results: After 1 year, the mean changes in the SER (±SE) and AL (±SE) in the SVL group were -0.81±0.06 D and 0.36±0.02 mm. Compared with SVL, the myopia control efficacy measured using SER was 67% (difference of 0.53 D) for HAL and 41% (difference of 0.33 D) for SAL, and the efficacy measured using AL was 64% (difference of 0.23 mm) for HAL and 31% (difference of 0.11 mm) for SAL (all p<0.01). HAL resulted in significantly greater myopia control than SAL for SER (difference of 0.21 D, p<0.001) and AL (difference of 0.12 mm, p<0.001). The mean BCVA (-0.01±0.1 logMAR, p=0.22) and mean daily wearing time (13.2±2.6 hours, p=0.26) were similar among the three groups. All groups adapted to their lenses with no reported adverse events, complaints or discomfort.

Conclusions: Spectacle lenses with aspherical lenslets effectively slow myopia progression and axial elongation compared with SVL. Myopia control efficacy increased with lenslet asphericity.

Trial registration number: ChiCTR1800017683.

Keywords: child health (paediatrics); clinical trial; optics and refraction; vision.

Conflict of interest statement

Competing interests: Jinhua Bao is an Associate Director of Wenzhou Medical University–Essilor International Research Centre. Adeline Yang, Ee Woon Lim, Daniel P. Spiegel and Björn Drobe are employees of Essilor International. This company supplied the study devices and holds the following patent applications related to this work: WO2019166653, WO2019166654, and WO2019166655. No conflicts of interest exist for the remaining authors.

© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Illustration of the study device providing a volume of myopic defocus (VoMD) (white shell) in front of the retina through 11 concentric rings of contiguous lenslets (A=depth of VoMD and B=distance from the retina). The calculations for the lenslets were based on the modified Atchison eye model using a retinal shape modified to match the peripheral refraction data of Chinese children. Spectacle lenses with highly aspherical lenslets (A=0.7 mm and B=1.2 mm), spectacle lenses with slightly aspherical lenslets (A=0.3 mm and B=1.0 mm) (illustrated and authorised by Dr. Damien Paillé from R&D AMERA, Essilor International).

Figure 2

Consolidated Standards of Reporting Trials flow chart of the study, showing participant randomisation, treatment group assignment, follow-up visits and data analysis. (Two participants switched to new spectacles because they wanted trendier frames instead of those provided by the study.) HAL, spectacle lenses with highly aspherical lenslets; PAL, progressive addition lenses; SAL, spectacle lenses with slightly aspherical lenslets; SVL, single-vision spectacle lenses.

Figure 3

Adjusted mean change from baseline spherical equivalent refraction (left panel) and axial length (right panel) in each treatment group over a 1-year period. Error bars represent 1 SE of the mean. 0 M=0-month baseline; 6 M=6-month follow-up; 12 M=12 month follow-up. HAL, spectacle lenses with highly aspherical lenslets; SAL, spectacle lenses with slightly aspherical lenslets; SVL, single-vision spectacle lenses.