Abstract
PURPOSE: To evaluate daily 0.05% atropine's effects on structural changes in the choroid and retina in myopic children. METHODS: This prospective cohort study included 100 children aged 6-15 years, of whom 83 completed 6-month follow-up. Participants received either nightly 0.05% atropine eyedrops or no pharmacologic treatment (all wore single-vision spectacles). Spherical equivalent (SE) and axial length (AL) were measured, and swept-source OCT angiography was used to assess choroidal thickness (CT), retinal thickness (RT), outer retinal layer (ORL), ganglion cell layer plus inner plexiform layer (GCL+IPL), inner nuclear layer (INL), peripapillary retinal nerve fiber layer (RNFL), choroidal vascular volume (CVV), choroidal vascular index (CVI), superficial and deep vascular complexes (SVC/DVC), and nerve fiber layer vascular density (NFVD). RESULTS: Atropine reduced myopia progression compared to controls (ΔSE: 0.11 vs -0.30 D; ΔAL: 0.01 vs 0.17 mm; P < 0.001). In the atropine group, 55.56% showed SE improvement and 42.22% exhibited AL shortening. Significant increases were observed in macular CT, CVV, RT, ORL, GCL+IPL, INL, and peripapillary RT, ORL, and RNFL, whereas CVI, SVC, DVC, and NFVD remained unchanged. Changes in macular CT, CVV, RT, and GCL+IPL were positively correlated with ΔSE and negatively with ΔAL. Increases in ORL and peripapillary RNFL were negatively correlated with ΔAL. CONCLUSION: Daily 0.05% atropine not only slowed myopia progression and axial elongation but also promoted thickening of choroidal and retinal layers. These structural changes suggest partial reversal of ocular growth, supporting the therapeutic role of atropine in myopia control. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100043506, https://www.chictr.org.cn/showproj.html?proj=122214, registered 21 February 2021). This study represents a secondary analysis of the registered trial; the control group was drawn from an ethically approved observational cohort.