Impact of optical correction with ordinary spherocylindrical spectacle lenses versus defocus incorporated multiple segments (DIMS) spectacle lenses on ocular alignment and binocular visual function in teenagers with myopia

To compare the effects of ordinary spherocylindrical spectacle lenses versus defocus incorporated multiple segments (DIMS) spectacle lenses on ocular alignment and binocular visual functions in teenagers with myopia over a 2-year period. 120 myopic teenagers aged 12–18 years were randomly allocated to wear either ordinary spherocylindrical single vision spectacle lenses (SV group, n = 60) or DIMS spectacle lenses (DIMS group, n = 60) for 2 years. After 2 years, the DIMS group exhibited significantly smaller exophoric shifts in ocular alignment compared to the SV group at distance (1.5 ± 2.2 vs. 3.4 ± 3.1 PD, p = 0.001) and near (3.7 ± 4.1 vs. 6.8 ± 5.4 PD, p < 0.001). The DIMS group also demonstrated better preserved stereoacuity [values log10-transformed for statistical analysis but presented here in arcsec for clinical interpretability] (32 ± 12 vs. 48 ± 20 arcsec, p < 0.001), near point of convergence (7.2 ± 2.3 vs. 9.5 ± 3.6 cm, p = 0.001), and fusional vergence ranges (positive: 24 ± 8 vs. 18 ± 7 PD, p = 0.002; negative: 14 ± 5 vs. 11 ± 4 PD, p = 0.01) than the SV group at 2 years. The mean myopia progression over 2 years was significantly slower in the DIMS group than the SV group (-0.72 ± 0.32 vs. -1.25 ± 0.45 D, p < 0.001), with less axial elongation (0.41 ± 0.18 vs. 0.65 ± 0.25 mm, p < 0.001). The proportions of participants with clinically significant changes in ocular alignment (≥ 10 PD exophoria), stereoacuity (≥ 0.3 log arcsec loss), and convergence (≥ 4 cm recession in near point of convergence) were significantly lower in the DIMS group compared to the SV group (all p < 0.05). In myopic teenagers, DIMS spectacle lenses used for optical correction were associated with smaller changes in ocular alignment and binocular visual functions, and slowed myopia progression by 42% in terms of spherical equivalent refraction (SER). These results suggest that DIMS lenses may be effective in controlling both refractive progression and certain binocular function changes in adolescents.