Evaluating the myopia progression control efficacy of defocus incorporated multiple segments (DIMS) lenses and Apollo progressive addition spectacle lenses (PALs) in 6- to 12-year-old children: study protocol for a prospective, multicenter, randomized controlled trial.

BACKGROUND

Myopia is increasing in prevalence and is currently recognized as a significant public health issue worldwide, particularly in China. Once myopia develops, appropriate clinical interventions need to be prescribed to slow its progression. Currently, several publications indicate that myopic defocus (MD) retards eye growth and myopia progression. However, no clinical trials have compared the outcomes of different MD spectacle lenses in the same observational group, especially in mainland China. The aim of the present study is to compare the myopia control efficiency of two different MD spectacle lenses: defocus incorporated multiple segments (DIMS) lenses and Apollo progressive addition lenses (PALs).

METHODS

The trial is designed as a 3-year, prospective, randomized, multicenter clinical trial of schoolchildren treated with DIMS lenses and PALs. A total of 600 Chinese primary school children aged 6-12 years will be recruited, and each group is intended to include 300 subjects. The inclusion criteria are myopia between - 1.00 and - 5.00 diopters and astigmatism ≤ 1.50 diopters. The follow-up time points will be 1 month (m), 3 m, 6 m, 12 m, 18 m, 24 m, 30 m, and 36 m. The primary outcome will be determined by the difference between the two groups in cycloplegic spherical equivalent refraction between baseline and the last follow-up visit. The secondary outcome is the axial length, and the exploratory outcomes include ocular biometric measures, peripheral refraction, binocular vision, accommodation, compliance, and the results of questionnaires related to wearing experiences.

DISCUSSION

The present study will be the first randomized controlled trial in myopic primary school children treated with DIMS lenses and PALs in China. The results will indicate whether and how much different MD mechanisms retard myopia progression and axial elongation. In addition, the comparison will provide information on the clinical efficacy and safety of DIMS lenses and PALs, including information related to wearing experiences and visual function.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR), ChiCTR1900025645. Registered on 3 September 2019. http://www.chictr.org.cn/showproj.aspx?proj=42927.