Comparison of Accommodative Parameters between Progressive Myopic and Emmetropic Children

Objective: To investigate differences in accommodative parameters between progressive myopic and emmetropic children, and to determine the potential role of accommodation in myopia. Methods: Thirty-four children with progressive myopia (SE of -0.75 D or more) and 34 children with emmetropia (SE between -0.50 D and 0.50 D) from December 2015 to May 2016 in Eye Hospital, Wenzhou Medical University participated in this case control study. Subjective accommodative amplitude (SAA), monocular distance accommodative facility (DAF) and accommodative stimulus-response curves (ASRCs) were measured. An independent samples t test was used to compare differences in accommodation between those two groups. Results: Mean SE was 0.18±0.28 D and -2.88±1.03 D for emmetropes and progressive myopes, respectively (t=-16.72, P 0.05). Progressive myopic children had a larger accommodative lag area and higher accommodative lag at 1 D, 2 D, 3 D, 4 D, 5 D than emmetropes (t=2.40, 2.78, 2.79, 2.49, 2.12, all P<0.05). Accommodative lag at 6 D was slightly higher in progressive myopes, but no significant difference was found (t=1.83, P=0.07). Conclusions: The features of accommodative function in progressive myopic children are not exactly the same as emmetropes. Progressive myopic children have a higher accommodative lag than emmetropes, suggesting that accommodative lag may play a role in myopia. Key words: children; progressive myopia; emmetrope; accommodation