Abstract
PURPOSE: To evaluate the effectiveness of 12 months of spectacle lens wear incorporating cylindrical annular refractive elements (CARE) in slowing myopia progression compared to single vision (SV) spectacle wear. METHODS: In an ongoing 2-year prospective, double-masked, multi-centre clinical trial, 240 Chinese children aged 6-13 years, spherical equivalent refractive error (SE) -0.75 D to -5.00 D were randomised to one of three groups of 80 participants each to wear: SV spectacle lens (N = 80), CARE spectacles (7 mm central clear zone surrounded by treatment zone incorporating CARE with mean surface power of +4.6 D) and CARE S (9 mm central clear zone surrounded by treatment zone comprising CARE with mean surface power of +3.8 D). Cycloplegic SE and axial length (AL) were measured at 6-month intervals. RESULTS: Compared to baseline, changes in SE and AL were significantly different between the groups at both 6 and 12 months (p < 0.001, linear mixed model). Adjusting for site, group, parental myopia and age, at 12 months, the estimated change in SE and AL with 95% CI with SV was -0.65 D (CI: -0.56 to -0.74 D)/0.32 mm (CI: 0.29-0.36 mm). In comparison, the estimated change in SE/AL at 12 months with CARE was -0.35 D (-0.26 to -0.44 D)/0.19 mm (0.15-0.22 mm) and with CARE S was -0.36 D (-0.27 to -0.46 D)/0.21 mm (0.18-0.25 mm) at 12 months. Progression was slower with CARE and CARE S compared to SV (p < 0.05) but did not differ from each other (p = 0.793 and 0.336 for SE and AL, respectively). CONCLUSIONS: In children with myopia, after 12 months of lens wear, both CARE and CARE S spectacle lenses significantly slowed myopia progression compared to SV lenses.