Twice versus once daily application of 0.01% atropine for myopia control in children: a randomised controlled trial.

BACKGROUND: To investigate the efficacy and safety of standard 0.01% atropine at different frequencies (twice daily versus once nightly) for myopia progression. METHODS: In this randomised controlled trial (ChiCTR2200055532), Participants aged 6-13 years with a spherical equivalent (SE) between -6.00 to -0.75D and a best corrected visual acuity of ≥0.8 were enrolled and randomised 1:1 to receive 0.01% atropine eye drops once nightly (QD group) or twice daily (BID group) for one year. The primary endpoint was the change in axial length (AL) after one year. RESULTS: Seventy participants were included and assigned to the QD (n = 34) and BID (n = 36) groups, respectively. After one year, the BID group exhibited a significantly smaller increase in mean AL compared with the QD group (0.21 ± 0.18 vs. 0.32 ± 0.14 mm, P = 0.002), corresponding to a 34% reduction in axial elongation. The BID regimen was 53% more effective in slowing SE progression than the QD regimen, with mean SE changes of -0.31 ± 0.50 vs. -0.66 ± 0.37D (P < 0.001). Safety parameters (e.g., amplitude of accommodation, tear film stability, intraocular pressure) remained similar between the two groups (all P > 0.05). Although mesopic pupil diameter (PD) increased more in the BID group (0.65 ± 0.63 vs. 0.27 ± 0.69 mm, P = 0.010), the difference was clinically acceptable and not observed in photopic PD (P = 0.297). CONCLUSION: Twice-daily administration of 0.01% atropine significantly enhances the management of axial elongation and SE progression compared with once-nightly dosing without increasing the risk of adverse effects.