To compare the effect of delaying progression of myopia in children between defocus incorporated multiple segments (DIMS) spectacle lens and orthokeratology.

A nonrandomized controlled clinical study was conducted.A total of 390 children (390 eyes) with myopia who were treated in the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2020 were included, with the spherical equivalent (SER) of -0.75 to -6.00 D. According to the willingness of patients and patients' guardians, the subjects were divided into DIMS group, orthokeratology group and single-vision spectacle lens group, with 130 cases (130 eyes) in each group, wearing DIMS spectacle lenses, standard or astigmatic design orthokeratology and conventional single-vision full-correction aspheric spectacle lenses, respectively.The SER of the eyes was measured using an automatic computerized refractometer in combination with subjective refraction before and one year after lens wear, and the axial length (AL) of the eyes was measured using IOLMaster.A total of 327 patients in the three groups met the inclusion and exclusion criteria, including 107 in the DIMS group, 112 in the orthokeratology group, and 104 in the single-vision spectacle lens group.All the right eyes were included in this study.The changes in SER and AL before and after wearing lenses for 1 year were compared among the three groups.The relationship between AL and SER changes and baseline data in the DIMS group was evaluated by Pearson linear correlation analysis.The study followed the Declaration of Helsinki, and the study protocol was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (No.2023-KY-0174-002). The subjects and their guardians were fully aware of the purpose and methodology of the study, and voluntarily signed an informed consent form.

There were statistically significant overall differences in SER and AL at different time points among the three groups (SER: F_group=7.065, P=0.009; F_time=183.730, P<0.001.AL: F_group=6.151, P=0.014; F_time=175.290, P<0.001). One year later, the differences in SER and AL changes among the three groups were statistically significant (F=7.065, P=0.009; F=6.151, P=0.014). The SER and AL of each group after 1 year was greater than the baseline, with the SER and AL and their changes significantly smaller in orthokeratology group and DIMS group than in single-vision spectacle lens group and greater in DIMS group than in orthokeratology group, showing statistically significant differences (all at P<0.05). Compared with single-vision spectacle lenses, wearing orthokeratology for 1 year can inhibit SER and AL progression by 58.3% and 59.0%, and wearing DIMS frame glasses for 1 year can inhibit SER and AL progression by 46.9% and 43.6%.The percentage of eyes with no change in SER was 5.77%(6/104), 24.11%(27/112) and 17.76%(19/107) in the single-vision spectacle lens group, orthokeratology group and DIMS group, respectively, and the percentage of AL was 0.00%(0/104), 8.93%(10/112) and 7.48%(8/107), respectively, showing statistically significant differences among the three groups (χ²=9.316, 8.676; both at P<0.001). The AL change in the DIMS group was weakly negatively correlated with age (r=-0.252, P=0.006).

Wearing DIMS spectacle lenses is not as effective as orthokeratology in delaying myopia in children, but it is significantly better than wearing conventional single-vision spectacle lenses.

Myopia; Childhood; Axial length, eye; Defocus spectacle lenses; Orthokeratology; Spherical equivalent refraction; Retinal defocus