Myopia control efficacy of spectacle lenses with highly aspherical lenslets: results of a 5-year follow-up study
Xue Li, Yingying Huang, Chenyao Liu, Xindan Chang, Zaifeng Cui, Qiulin Yang, Björn Drobe, Mark A. Bullimore, Hao Chen, Jinhua Bao
Abstract
Abstract Purpose To evaluate myopia control efficacy in myopic children wearing spectacle lenses with highly aspherical lenslets (HAL) for 5 years. Methods This is a randomized, double-masked extended trial. Myopic children aged 8 to 13 years who were originally allocated to the HAL group in the 2-year clinical trial. The HAL group underwent a 5-year assessment for myopia progression using cycloplegic spherical equivalent refraction (SER) and axial length (AL). An extrapolated single-vision spectacle lenses (ESVL) group was used as a control group. The 5-year myopia progression and axial elongation of the ESVL group was calculated based on the 2-year data from the single-vision spectacle lenses group in the same clinical trial, and the data for the following 3 years was estimated by assuming an annual reduction in SER by 9.7% and in AL by 15%. A generalized linear model approach was used to evaluate the treatment efficacy. The validity of the ESVL group was evaluated by comparing myopia progression in the first year of the 3-year estimates with a single-vision spectacle lenses (SVL2) group from a 1-year extended study of the same clinical trial. Results Forty-three participants from the original HAL group completed the 5-year visit (74%). Five-year myopia progression [mean ± standard error (SE)] in the HAL group was − 1.27 ± 0.14 D. Compared with the ESVL (− 3.03 ± 0.18 D), myopia progression was − 1.75 ± 0.24 D less for the HAL group ( P < 0.001). The mean AL elongation over 5 years was 0.67 ± 0.06 mm for the HAL group compared with 1.40 mm in the ESVL group ( P < 0.001), AL elongation was slower by 0.72 ± 0.10 mm for the HAL group ( P < 0.001). No significant differences were found for myopia (− 0.58 ± 0.04 D vs . − 0.56 ± 0.05 D) or AL elongation (0.28 ± 0.02 mm vs. 0.28 ± 0.02 mm) between the ESVL group and SVL2 group ( P SER = 0.83; P AL = 0.93) in year 3. Conclusions In this 5-year study, HAL spectacles reduced the rate of myopia progression and axial elongation, preventing the equivalent of 3 years of myopia progression and axial elongation. Long-term use of HAL spectacles also decreased the incidence of high myopia. Extrapolated control groups are valid for evaluating myopia progression in long-term studies. Trial registration The study was registered at the Chinese Clinical Trial Registry (ChiCTR2100047262), https://www.chictr.org.cn/showproj.html?proj=127182 .