Analysis Of Correlation Between Refractive Degree Of Myopia And Ocular Optical Components

Objective:To evaluate the correlation between refractive degree of myopia and refractive components.Materials and Methods:The ocular optic parameters of main refractive components were measured in 158 cases(316 eyes).The optic parameters were determinded with A-scan ultraso-und and keratometry.The parameters included cornea refractive power(K1,K2,△K=K2-K1),anterior chamber depth(ACD),lens thickness(LT),vitreous length(VL) and axial length(AL).The cases were divided into groups according to refractive degree and axial length.The datas were analyzed by one-way ANOVA,independent-samples T test and Spearman correlation analysis based on SPSS 16.0.Results:(1) refractive degree:①The ACD,VL,and AL were statistically significant different between groups of myopia and emmetropia(P＜0.05),and there were statistically significant difference in all kinds of myopic groups about the VL,AL(P＜0.05).Refractive degree of myopia was correlated with ocular optical parameters which including K2,△K,VL,AL,especially with VL(r=-0.730,p＜0.001) and AL(r=-0.735,p＜0.001).②In the low and moderate myopia groups,AL showed a negative correlation with K1,K2,LT,however,AL was positively correlated with ACD.AL was found a positive correlation with VL in the high myopia group.③The variation trends of correlation coefficient between four groups of refractive degree and ocular optic parameters including K1,K2,△K,ACD,LT showed a consistency, meanwhile,VL and AL had a significantly consistency.(2)Axial length:Refractive degree showed a correlation with△K,VL,AL(P＜0.05)in the axial myopia(more than 24mm),however refractive degree showed a correlation with△K(P＜0.05) in the non-axial myopia(less than 24mm),and there was a statistically significant difference between two groups,including refactive degree of myopia and ocular optic parameters.(P＜0.05).Conclusion:(1)Myopia was predominantly resulted from elongation of the axis. Moreover,it was mainly influenced by cornea refractive power.(2)In the eyes of low and moderate myopia,with the elongation of axis,the eye itself could put off the deepening of refractive degree of myopia through some compensatory mechanisms, however high myopia was mainly resulted from the elongation of axial length which was caused from the elongation of vitreous body.(3)Astigmatism of cornea is ascending with the increasing od refractive degree.