A Study on the Profile and Factors of the Higher Order in Myopia

Objective To analyze the distribution of the higher-order aberrations in the population of China with myopia and astigmatism,and to determine whether the pupil size,degree of myopia and astigmatism of higher-order aberrations.Methods One hundred and three myopic astigmatism eyes were evaluated before refractive surgery by using a Hartmann-Shack method.The root mean square(RMS)values of higher-order aberrations for each subject with pupil diameters of 5.0 mm and 6.0 mm were calculated.The subjects were divided into following groups:high myopia(-6.00 D),medium myopia(-3.00～-6.00 D)and low myopia(≤-3.00 D),high astigmatism(≥0.75 D)and low astigmatism(0.75 D).Results Higher-order aberrations were increased significantly with increasing pupil size.The RMS values were decreased from 3rd to 5th order aberrations with pupil diameters of 6.0 mm in the same eye.Spherical aberration and coma aberration were affected by high myopia;low and moderate myopia did not effect higher order aberrations.Astigmatism only affected the coma aberration,but not spherical aberration.ConclusionThe aberrations increase with the pupil diameters,the increasing of refractive error such as myopia and astigmatism.