Correlation of Corneal Astigmatism and Whole-Eye Astigmatism in Adolescent Myopic Patients

Objective To investigate the correlation between corneal astigmatism whole-eye astigmatism as well as the relation between astigmatism and myopic degree in adolescent myopic patients.Methods For 213 adolescent patients (422 eyes) corneal topography and manual retinoscopy were performed.The correlation in the degree as well as the axis of the corneal astigmatism and the whole-eye astigmatism were analyzed.The relation between astigmatism and the degree of myopia was also analyzed.Results The accordance rates in the axis of corneal astigmatism and whole-eye astigmatism were respectively 34.4% (absolute difference less than 5°) and 54.0% (absolute difference less than 10°).The accordance rates in the value of corneal astigmatism and whole-eye astigmatism were 35.5% (absolute difference less than 0.25 D) and 66.4% (absolute difference less than 0.50 D).Corneal astigmatism was highly correlated to whole-eye astigmatism(P=0.000).In the high myopia group,the degrees of corneal astigmatism and whole-eye astigmatism were significantly higher than those in the moderate or low myopia group (P0.05).Conclusion The result of the corneal topography can be used as the approximate assessment and reference to the whole-eye astigmatism,however retinoscopy should be applied to correct the refractive error in eyes of myopia with astigmatism.