Efficacy of cylindrical annular refractive elements (CARE) spectacle lenses in slowing myopia progression over 2 years.

Abstract

PURPOSE To evaluate over a 2-year period, the efficacy of spectacle lenses incorporating cylindrical annular refractive elements (CARE) in slowing myopia progression compared to single vision (SV) spectacle wear. DESIGN Double-masked, multi-center, randomized clinical trial. METHODS A total of 240 Chinese children aged 6-13 yrs, spherical equivalent refractive error (SE) -0.75D to -5.00D were randomized to one of three groups of SV spectacle lens, CARE spectacles (7mm central clear zone surrounded by treatment zone incorporating CARE with mean surface power +4.6D), and CARE S (9mm central clear zone surrounded by treatment zone comprising CARE with mean surface power +3.8D). Cycloplegic SE and axial length (AL) were measured at six-monthly intervals. RESULTS Progression (mean ± SD) in SV wearing eyes after 24 months of SPL wear was -1.15 ± 0.63 D/ 0.59 ± 0.26 mm with SV for SE/AL, respectively. In comparison, myopia progression was significantly slower with both CARE-0.73 ± 0.63D/ 0.40 ± 0.26 mm, p<.0001 and CARE S -0.80 ± 0.56D/ 0.44 ± 0.25 mm, p<.0001. Progression did not differ significantly between CARE lenses. Adjusting for site, group, age, gender and baseline value at 24 months, CARE showed an absolute difference in SE of 0.44D (95% CI: 0.21 to 0.66D) and CARE S 0.41D (95% CI: 0.21 to 0.66D) compared to SV. AL reduction was 0.20 mm (95% CI: 0.10 to 0.30mm) with CARE and 0.17 mm (0.07 to 0.26mm) with CARE S as compared to SV. CONCLUSIONS Over a 2-year period, lenses incorporating CARE significantly slowed myopia progression as compared to SV lenses.