ABSTRACT
Background Image clarity during near work is influenced by several factors,such as accommodative lag,pupil size and monochromatic aberrations.Since image clarity during extended reading at near distance has been cited as a possible inducement of myopia in childhood and a possible difference between myopic and emmetropic people throughout life,it is important to examine these factors in myopic and emmetropic myopic juvenile during reading at near distance. Objective The aim of this study was to investigate the relationships among wavefront aberrations,accommodative response and pupil size in early onset and progressive myopes eyes under the different reading status and explore the possible mechanism of the development of myopia as well. Methods Fiflyseven subjects aged from 12 to 16 years were enrolled and grouped as emmetropes,the onset of myopes and progressive myopes.Reading material were Chinese novels presented by rapid serial visual presentation at a distance of 25 cm. Accommodative response and pupil size were recorded by a Grand Seiko WV-500 autorefractor.The Image J software was used to calculate the pupil diameter.Wavefront aberrations were then measured with a WASCA wavefront analyzer. Results Aberrations and accommodative response showed large inter-subjeet variability.With accommodative stimulus of 4 diopter,the accommodative lag in the early-onset of myopes group and progressive myopes group were ( 1.72 ±0. 53) D and ( 1.74 ±0. 44) D, showing larger value in comparison with ( 0. 96 ±0. 55) D of emmetropes group( t＝4.25 ,t=4.47 ,P0. 05). The mean value of pupil diameter, total RMS value, high-order RMS value, spherical aberration and coma were all significantly reduced with the stimulus varied from 0 D to 4 D( P0. 05). Conclusion The early-onset of myopes and progressive myopes had larger accommodative lag. The lower sensitivity to defocus at near reading distance,inducing the larger accommodative lag and hyperopic defocus may be linked to the developing myopia.