Authors and their organizations：
Ji Kou 1 2, Ye Wu 1 2, Si Lei 1 2, Ling Xiong 1, Xiaohang Chen 1 2, Longqian Liu 1 2
1Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.
2Laboratory of Optometry and Vision Sciences, West China Hospital, Sichuan University, Chengdu, China
Purpose: To assess second-year myopia progression in children after a 1-year randomised controlled trial of individualised ocular refraction customisation (IORC) spectacle lenses, customised to each eye's peripheral refraction.
Methods: A total of 161 children were randomised to wear IORC lenses with high (+4.50 D, IORC-H), medium (+3.50 D, IORC-M) or low (+2.50 D, IORC-L) myopic defocus or single-vision lenses (SV). In year 2, all children received IORC-H, forming the IORC-H1/H2/H3/H4 groups, respectively. An external SV (eSV, n = 42) group was matched to year 2 baseline parameters. Spherical equivalent refraction (SER) and axial length (AL) were measured every 6 months.
Results: Compared with the eSV group (12-month mean [SD] changes: SER -0.56 [0.44] D, AL 0.32 [0.16] mm), all IORC-H intervention groups demonstrated slower progression in year 2 (IORC-H1: -0.17 [0.37] D, 0.19 [0.14] mm; IORC-H2: -0.25 [0.41] D, 0.17 [0.16] mm; IORC-H3: -0.24 [0.36] D, 0.17 [0.14] mm; IORC-H4: -0.22 [0.40] D, 0.14 [0.17] mm; p < 0.05), with no intergroup differences (p > 0.05). Compared with the SV/eSV group, the IORC-H1 group presented 2-year reductions of 0.84 D and 0.38 mm in the SER and AL, respectively (p < 0.001) and exhibited minimal progression during the initial 0-6 months (p < 0.05), followed by constant progression over three subsequent 6-month intervals (p > 0.05).
Conclusions: Switching to IORC-H in year 2 significantly reduced myopia progression and axial elongation. Maximal control efficacy occurred in the first 6 months, with sustained clinically meaningful effects thereafter.
