Ethnic and dose-dependent differences in atropine efficacy for myopia control: a systematic review and meta-analysis

BACKGROUND/AIM: Clinical uncertainty remains regarding optimal atropine concentration, treatment duration and potential differences in efficacy for myopia control between Asian and non-Asian children. This systematic review and meta-analysis evaluated the efficacy of different concentrations of atropine for myopia control, comparing outcomes among East Asian, South Asian and white European children. METHODS: Five databases were searched for randomised controlled trials (RCTs) including children ≤16 years with myopia who received atropine treatment. Thirty-four RCTs with ≥12 months of follow-up were included. Weighted mean differences (WMD) in spherical equivalent refraction (SER) progression and axial length (AL) elongation were pooled by atropine concentration and ethnicity. RESULTS: Compared with controls, atropine significantly reduced myopia progression across all concentrations: <0.1% (WMD in SER: 0.44 (95% CI 0.35 to 0.52) dioptres (D)/year; AL: -0.20 (95% CI -0.24 to -0.16) mm/year), 0.1% to <0.5% (0.81 (95% CI 0.50 to 1.13) D/year) and ≥0.5% (1.06 (95% CI 0.88 to 1.24) D/year; -0.36 (95% CI -0.40 to -0.33) mm/year). The pooled effect on SER and AL progression across all concentrations was greater in East Asians (0.63 (95% CI 0.50 to 0.76) D/year; -0.26 (95% CI -0.31 to -0.20) mm/year) than in South Asians (0.40 (95% CI 0.11 to 0.70) D/year; -0.13 (95% CI -0.21 to -0.05) mm/year) or white Europeans (0.18 (95% CI 0.11 to 0.25) D/year; -0.11 (95% CI -0.16 to -0.05) mm/year). CONCLUSION: Atropine slows myopia progression in a dose-dependent manner in studies with 1-5 years of follow-up. Efficacy appears greater in Asian children, particularly East Asians, who also exhibit greater photopic pupil dilation. These findings support the role of atropine in myopia control and highlight the importance of ethnicity-specific considerations when prescribing and tailoring treatment strategies. PROSPERO REGISTRATION NUMBER: CRD42023454104.