Purpose To determine the effects of muscarinic receptor antagonists including atropine eyedrops and pirenzepine gel on slowing the progression of myopia in children.
Methods Relevant studies that assessed the effects of atropine or pirenzepine on slowing myopia progression in children were searched from MEDLINE (1966 to November 2011), EMBASE(1950 to November 2011) and Cochrane Library in the meta-analysis. Two assessors independently reviewed the titles and abstracts, extracted data using a data collection form and assessed the quality of included studies. Primary outcomes were mean change in cycloplegic spherical equivalent and the proportions of children with fast (greater than -1.0D/y) or slow (less than -0.50D/y) myopia progression from baseline to the end of the intervention period.
Results Eight randomized controlled trials (RCTs) and 5 cohort studies with 1696 children aged from 5 to 14 years old were included. The children had a baseline cycloplegic refraction ranging from -0.50 D to -9.75D and were followed up for 20.25±8.32 (12.00~38.40) months. As a whole of muscarinic receptor antagonist, the mean differences in the progression of myopia between two groups were 0.53 D (95% CI, 0.30~0.75; P<0.00001) and 0.56 D (95% CI, 0.26~0.86; P=0.0003) for all studies and randomized controlled trials only, respectively. Five RCTs and 5 cohort studies showed that atropine could significantly slow myopia progression in children with differences of 0.69 D (95% CI, 0.28~1.09; P=0.001) and 0.44 D (95% CI, 0.17~0.70; P=0.001), respectively. Three RCTs on pirenzepine gel showed that it could slow the progression of myopia by 0.32 D (95% CI, 0.21~0.43; P<0.00001). The proportions of children with slow myopia progression were greater in the group treated with muscarinic receptor antagonists (odds ratio, 14.57, 95% CI, 10.00~21.22; P<0.00001), so does that of fast myopia progression in the control group (odds ratio, 0.08, 95% CI, 0.04~0.18; P<0.00001).
Conclusions Muscarinic receptor antagonists could significantly slow the progression of myopia in children by 0.53 D compared with controls, with greater effect in atropine (0.69 D) and smaller effect in pirenzepine (0.32 D). The effect of muscarinic receptor antagonists on slowing myopia progression is more than ten times stronger than that of controls. |
