AIM: To evaluate the effect of astigmatism on optical quality in young myopic patients by a double-pass system.

METHODS: Retrospective series of case studies, 258 young myopia patients(479 eyes)were selected and divided into four groups according to the degree of astigmatism: -1D< astigmatism ≤0 for Group L, -2D< astigmatism ≤-1D for Group M, -3D< stigmatism ≤-2D for Group H, -4D≤ astigmatism ≤-3D for Group S. Optical Quality Analysis System(OQASTM II)based on double-pass system was used to examine the patient's optical quality, the following parameters were analyzed: MTF cutoff, OSI, SR, OV100%, OV20%, and OV9%.

RESULTS: As the degree of astigmatism incresaes, MTF cutoff, SR, OV100%, OV20% and OV9% gradually decrease and OSI increases; Except for Group L and the Group M(P>0.05), the difference of MTF cutoff and OSI between the other groups were statistically significant(P<0.05). In this study, there were no significant correlation between MTF cutoff and SR in age, and negative correlation with the degree of astigmatism. OSI had no significant correlation with age and was positively correlated with the degree of astigmatism.

CONCLUSION: The degree of astigmatism has a significant influence on the objective optical quality of low-to-moderate myopia in young people. As the degree of astigmatism increases, the optical quality gradually decreases.