Using tablet computer at a short distance is one of the risk factors resulting to pathogenesis and progression of myopia.Studying the effect of such device on accommodative system of human eyes can provide further insights into myopia control.
This study was to explore the influences of playing iPAD game for a short duration on accommodative response, accommodative microfluctuation and pupil diameter in adolescent myopia patients.
Sixty adolescent myopic patients were included in Peking University People’s Hospital from August 2014 to April 2015, with the mean age (11.6±2.6) years and mean spherical equivalent refraction (SER) (-2.38±1.08)D.The patients were randomly divided into 3 groups according to different playing duration of iPAD game, including 3-minute group, 5-minute group and 10-minute group.An open-field infrared refractometer was used to record pupil diameter and accommodation-associated data before and after playing iPAD game.Accommodative response was defined as the difference between the recorded value and theoretical accommodative response, and root mean square (RMS) was used to describe the amplitude of accommodative microfluctuation.One-dimension discrete Fourier transformation was used to analyze spectral characteristic of accommodative response curve.Paired ttests were used to compare these accommodative parameters before and after playing game, while Wilcoxon signed-rank tests were applied for analyzing high frequency component of accommodative microfluctuation.This research conforms to the declaration of Helsinki, and was approved by Peking University People’s Hospital Ethics Committee, all the subjects and their guardian signed informed consent.
The accommodative response values before and after playing iPAD game in 10-minute group were (0.81±0.29)D and (0.74±0.27)D, respectively, with significant difference between them (t=2.263, P=0.036), and no significant differences were found in the accommodative response values before and after playing iPAD game in the 3-minute group and 5-minute group (both at P>0.05). The RMS after playing iPAD game was (0.31±0.08)D in the 10-minute group, which was significantly higher than (0.27±0.09)D before playing iPAD game (t=-2.259, P=0.036). The high-frequency spectral power of accommodative response curves in all the three groups were increased after playing iPAD game in comparison with before playing iPAD game, with significant differences in the 5-minute group and 10-minute group (Z=-2.213, -2.016; both at P<0.05), and the pupil diameters were significantly decreased after playing iPAD game in comparison with before playing iPAD game, with significant differences in the 5-minute group and 10-minute group (t=2.428, P=0.026; t=2.515, P=0.021).
Short-term exposure to iPAD does not deteriorate accommodative lag in adolescent myopic patients.However, the increase of amplitude and high-frequency spectral power of accommodative microfluctuation, together with accommodation lag will result in blurred images and may bring adverse effects on myopic eyes.