Age-related results over 2 years of the multicenter Spanish study of atropine 0.01% in childhood myopia progression

Abstract

To evaluate the age-related efficacy and safety of atropine 0.01% eye drops over 2 years for myopia control in a multicentric pediatric Spanish cohort. A non-controlled, interventional, prospective multicenter study was conducted as an extension of the Spanish Group of Atropine Treatment for Myopia Control Study (GTAM 1). Children aged 6-14 years with myopia from - 2.00 to - 6.00 D, astigmatism < 1.50 D and documented annual myopic progression of at least - 0.50 D under cycloplegic examination were recruited. From the original cohort of 105 participants, 92 children who had been receiving atropine 0.01% eye drops once nightly in each eye for 1 year continued their participation in this extended study (GTAM 2). All the patients underwent a standardized quarterly follow-up protocol, which included measurements of best-corrected visual acuity (BCVA), cycloplegic autorefraction, axial length (AL), anterior chamber depth (ACD), and pupil diameter. The study sample was divided into three age groups: 6-8, 9-11, and 12-14 years old. The mean change in cycloplegic spherical equivalent (SE) and axial length (AL) during the 24 months of follow-up was analyzed. Correlations between SE and AL, as well as the distribution of annual progression, were evaluated. Adverse effects were recorded using a specific questionnaire. Finally, 81 children completed the follow-up and were included in the analysis. Over the 2-year period, the mean changes in SE and AL were - 0.88 ± 0.60 D and 0.49 ± 0.25 mm, respectively. Additionally, 51 patients (63%) experienced SE annual progression lower than - 0.50 D. The correlation between the progression of SE and AL during the total period of treatment was mild (r = - 0.36; p < 0.001). There were no differences between the first and the second year of treatment in the progression of SE (- 0.42 ± 0.41 D versus - 0.45 ± 0.39 D; p = 0.69) or AL (0.25 ± 0.16 mm versus 0.23 ± 0.14 mm; p = 0.43). Older patients (12-14 years old) showed less AL progression than younger children (6-8 years old): 0.36 ± 0.18 mm versus 0.59 ± 0.30 mm; p = 0.01. Adverse effects were mild, infrequent, and decreased over time. On average, the myopia progression in control groups from other published biannual studies exceeded that observed in our study. Over 2 years, atropine 0.01% demonstrated a safe treatment for controlling myopia progression in a multicentric cohort of Spanish children. The effect remained stable during this period. Older patients exhibited a more favorable response in terms of AL enlargement. However, further studies are needed to investigate the age-related effect of low-dose atropine in the Caucasian population.