Short-term Effect of Distant-image Screen on Myopia Control in Children and Comparison with Tablet Computer

Background To evaluate the effect of distant-image screen on myopia prevention and control. Methods Cross-designed randomized controlled trial. A total of 40 children were recruited. The subjects were randomly assigned to single-vision spectacle (SVS) lenses group or defocus incorporated multiple segments (DIMS) lenses group.In each group, participants were randomly allocated to tablet computer group (TC)or distant-image screen (DIS)group, and exchanged after 3 to 7 days. Participants were asked to watch videos for 90 minutes. Outcomes including choroid thickness (ChT) were measured before and after watching video. A two-stage cross-design analysis of variance and linear mixed model (LMM)were used to analyze the effects. Results 40 children were recruited, with an average age of 10.58 ± 1.48 years and an average spherical equivalent error (SER) of -2.11 ± 1.09 diopter (D). There were no statistical difference in baseline data. For participants wearing SVS or DIMS ,there were no statistical difference in the change of accommodative microfluctuation (AM), accommodative lag (ACL), axial length (AL) ,visual acuity between the DIS group and TC group (P > 0.05). For participants wearing SVS, the changes in ChT measured at 1mm inferior to the fovea (P = 0.036) and 1mm from the temporal side to the fovea (P = 0.032) in the DIS group were higher than that in the TC group,however, for participants wearing DIMS, there was no statistical difference between DIS group and the TC group (P > 0.05). Results of LMM analysis showed that the combination of glasses type and screen type had an interactive effect on ChT measured at the fovea (P = 0.027), 1mm from the nasal side of the fovea (P = 0.038), and 1mm from the temporal side of the fovea (P = 0.026). Conclusion The distant-image screen helps reduce the ChT thinning during video watching, indicating it might have an effect on myopia prevention and control.