Assessment of binocular vision and accommodation in myopic children wearing defocus incorporated multiple segments (DIMS) spectacle lenses for 24 months

Purpose

This study aimed to determine the changes in binocular vision (BV) and accommodation in Malay myopic children following long-term wear of Defocus Incorporated Multiple Segments (DIMS) spectacle lenses for 24 months.

Methods

Twenty-three Malay myopic children aged 7–12 years were enrolled in this prospective, self-controlled study. DIMS spectacle lenses were prescribed, and analyses were conducted at baseline, 12, and 24 months. Assessments included stereopsis, near point of convergence (NPC), phoria, positive/negative fusional vergence (PFV/NFV), amplitude of accommodation (AA), accommodative lag, positive/negative relative accommodation (PRA/NRA), and accommodative convergence to accommodation (AC/A) ratio. Visual acuity (VA), cycloplegic refraction (SER) and axial length (AL) were monitored. Data were analyzed using repeated-measures analysis of variance (ANOVA) within-subject or the Friedman test, with Bonferroni correction applied. p < 0.05 was considered statistically significant.

Results

Statistically significant changes were observed after 24 months, including median changes in NPC (receded by 2 cm, p < 0.001), AA (reduced by 1.67D, p = 0.002), distance PFV break (increased by 8Δ, p = 0.026) and recovery (increased by 6Δ, p = 0.033), distance NFV break (no change, p = 0.043), stereopsis (improved by 10″, p < 0.001), accommodative lag (reduced by 0.25D, p = 0.002), and AC/A ratio (increased by 1Δ/D, p < 0.001). Additionally, distance and near VA improved (p < 0.001), while SER and AL increased (p < 0.001).

Conclusion

: Wearing DIMS spectacle lenses for 24 months resulted in changes in BV and accommodation while slowing myopia progression. Regular NPC monitoring is recommended to maintain optimal BV function and visual comfort in children wearing DIMS lenses.