Abstract
Purpose :
Axial eye elongation is both a part of normal development and a marker of myopia progression. Axial length (AXL) centiles may be a useful tool for predicting axial eye growth and assessing treatment efficacy. We investigated the efficacy of atropine 0.01% eye drops with AXL centiles.
Methods :
The Myopia Outcome Study of Atropine in Children (MOSAIC) is a double-blind, randomized controlled trial in which 250 myopic 6-16 year-olds were randomized 2:1 to either 0.01% atropine or placebo eye drops nightly for 2 years. AXL was assessed using partial coherence interferometry (Aladdin, Topcon, Tokyo, Japan) and AXL centile calculated from reference databases (Ocumetra, Dublin, Ireland). Predicted AXL change was calculated by assuming an eye would remain on the baseline centile and the difference in actual – predicted AXL change used as the outcome. Data from both eyes were analysed using a clustered Wilcox rank sum test to test for differences in actual vs predicted AXL centile change.
Results :
At baseline, there were no significant differences between the atropine 0.01% and placebo groups, respectively, in mean age (11.8 vs 11.8 years), sex (61% vs 64% female), mean AXL (24.86 vs 24.99 mm) or median [interquartile range (IQR)] AXL centiles (96.5% [87.7-99.3] and 97.1% [86.9-99.3]; all p>0.05). Median (IQR) actual vs predicted AXL change, respectively was 0.34 (0.17-0.57) vs 0.30mm (0.24-0.41; p=0.07) in the placebo group, and 0.28mm (0.14-0.47) vs 0.29mm (0.20-0.43; p=0.15) in the atropine 0.01% group (treatment difference=-0.04mm, p=0.32). When divided into upper and lower halves of centiles (AXL centile >96.7% vs ≤96.7%), participants in the upper centiles on atropine 0.01% progressed significantly slower than predicted (median 0.33 vs 0.42mm, respectively, p=0.001), whereas placebo participants did not (0.45 vs 0.40 mm, p=0.62) and both atropine 0.01% and placebo groups in the lower half of centiles progressed faster than predicted (atropine: 0.24 vs 0.22mm, p=0.01; placebo: 0.30 vs 0.25mm, p=0.047).
Conclusions :
In eyes at a higher baseline AXL centile, progression was significantly slower than predicted in the atropine 0.01% group but not significantly different from predicted in the control group. In eyes with lower baseline AXL centiles both the atropine group and control groups progressed slightly faster than expected, at 0.01mm/year for atropine and 0.025mm/year for the control group.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.