Abstract
PURPOSE: To investigate the 2-year myopia control efficacy of Lenslet-ARray-Integrated (LARI) lenses with positive (PLARI) and negative (NLARI) power lenslets and the effect of switching lens designs. METHODS: A total of 218 children, who were randomly assigned to wear PLARI, NLARI, or single-vision (SV) lenses in Phase 1 continued in this randomized, double-masked extended trial for an additional year (Phase 2). Participants were randomly assigned to one of six groups: SV to PLARI, SV to NLARI, PLARI to PLARI (P-PLARI), PLARI to NLARI (P-NLARI), NLARI to PLARI (N-PLARI), and NLARI to NLARI (N-NLARI). In year 2, the change in spherical equivalent refraction (SER) and axial elongation (AE) from the SV group were extrapolated based on published data [the extrapolated single vision (ESV) group]. Linear models were used to determine differences in SER changes and AE among groups in 2 years and in Phase 2 only. RESULTS: After 2 years, the SER changes (- 0.87 ± 0.68 D, - 0.64 ± 0.86 D, - 0.68 ± 0.54 D, and - 0.75 ± 0.62 D, respectively) and AE (0.44 ± 0.33 mm, 0.33 ± 0.32 mm, 0.36 ± 0.23 mm, and 0.39 ± 0.25 mm, respectively) of P-PLARI, P-NLARI, N-PLARI, and N-NLARI were significantly smaller than those in the ESV group (SER: - 1.24 ± 0.77 D, all P < 0.05; AE: 0.63 ± 0.33 mm, all P < 0.001). In Phase 2, there was no significant difference in SER changes among the four LARI groups and ESV group (P = 0.58). In Phase 2, AE of the P-NLARI and N-PLARI groups was significantly smaller than the ESV group (P < 0.001 and P = 0.001), and AE of the P-PLARI and N-NLARI groups were slightly smaller than that of ESV group (P = 0.054 and P = 0.10), but there were no significant differences in AE among the four LARI groups (all P > 0.05). CONCLUSIONS: Wearing LARI lenses for 2 years effectively slowed myopia progression and AE. Switching to another LARI design after 1 year improved myopia control efficacy, in terms of AE, during the second year, but not SER progression. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200057210. Registered 03 March 2022, https://www.chictr.org.cn/bin/project/edit?pid=152900 .