Impact of Defocus Incorporated Multiple Segments Spectacles Versus Single Vision Spectacles on Myopia Control and Astigmatic Changes in Adolescents.

PURPOSE: To evaluate the effects of Defocus Incorporated Multiple Segments (DIMS) spectacles versus Single Vision Spectacles (SVS) on myopia control and astigmatic changes in adolescents with myopia.

METHODS

This retrospective study included 153 myopic children aged 7-14 years who attended our clinic between January 2022 and March 2023 (86 in the DIMS group and 67 in the SVS group), with a follow-up duration of one year. Axial Length (AL) and Corneal Astigmatism (CA) were measured using the OA-2000. Cycloplegic refraction was used to obtain Spherical (S), Cylinder Angle (C), and Spherical Equivalent (SE). Total astigmatism (TA) and corneal astigmatism J0/J45 components were calculated using Thibos' vector analysis. Pre- and post-treatment changes were analyzed using paired t-tests, while between-group comparisons were assessed using the Mann-Whitney U test, independent-samples t-test, and general linear model.

RESULTS

After one year of wear, the DIMS group exhibited significantly less myopic progression than the SVS group in both Spherical Equivalent and axial elongation, ΔSE: -0.39 ± 0.39 D vs. -0.72 ± 0.47 D; ΔAL: 0.23 ± 0.15 mm vs. 0.37 ± 0.22 mm; p < 0.01. No significant differences were observed in total astigmatism or corneal astigmatism between groups, ΔTA: -0.22 ± 0.07 D vs. -0.16 ± 0.06 D; ΔCA: -0.16 ± 0.06 D vs. -0.12 ± 0.01 D; p > 0.01. However, the DIMS group showed significantly greater increases in oblique components of total and corneal astigmatism compared with the SVS group after one year (p < 0.05; Table 1, Figure 1 and Figure 2).

CONCLUSIONS

DIMS lenses effectively slow myopic progression in adolescents by reducing Spherical Equivalent shift and suppressing axial elongation. Compared with SVS lenses, DIMS wear reduces horizontal/vertical astigmatic components but may increase oblique total and corneal astigmatism over long-term use. These findings highlight the importance of monitoring directional astigmatic changes during DIMS intervention, particularly in children with high baseline or oblique astigmatism.