The synergistic efficacy and safety of combined low-concentration atropine and orthokeratology for slowing the progression of myopia: A meta-analysis

Purpose To explore the efficacy and safety of combined low-concentration atropine and orthokeratology (OK) for slowing the progression of myopia. Methods We performed a systematic search of English and Chinese databases to collect potentially eligible randomised controlled trials (RCTs), nonrandomised controlled trials (non-RCTs) and retrospective cohort studies (REs) published between the establishment of the database and 1 January 2022. The weighted mean difference (WMD) and 95% confidence interval (CI) were calculated for each outcome. Results Fifteen studies were ultimately included in the meta-analysis, which indicated that compared with OK lenses alone, the combination of low-concentration atropine with OK lenses significantly slowed axial growth (WMD = -0.12 mm; 95% CI: -0.13 to -0.11, p < 0.001) and reduced the rate of change of the spherical equivalent refraction (WMD = 0.15 D; 95% CI: 0.06 to 0.24, p < 0.001). Additionally, the combined treatment may cause a slight increase in pupil diameter (WMD = 0.62 mm; 95% CI: 0.42 to 0.81, p < 0.001). No significant difference in the amplitude of accommodation, intraocular pressure, tear film break-up time or corneal endothelial cell density was found between the OK and combination therapy groups. Conclusions The combination therapy of low-concentration atropine and OK lenses had a greater effect in slowing myopia progression during a 6-to-12-month treatment interval and was still effective over a 24-month period. Increased pupil diameter was the major side effect of the combination therapy, with no negative impact on the amplitude of accommodation, intraocular pressure, tear film break-up time or corneal endothelial cell density.