ABSTRACT
Objective To observe the distribution of cornea Q value in adult myopia,and its relationship with age,sex,eye and refraction.Design Prospective case series.Participants Consecutive 510 patients (1020 eyes) of myopia of adults.Methods Cornea Q values were obtained with OrbscanⅡz Anterior Segment Analysis System in all subjects of adult myopia.Normal distribution test of Q value and correlation analysis with sphere,cylinder,sex,and age were performed.Main Outcome Measures Q value of cornea,corre- lation coefficient.Results In 1020 eyes of adult myopia,the mean Q value was-0.27?0.16 (range from-0.86 to 0.25) with near nor- mal distribution.The difference of Q value between right eyes and left eye was not statistically significant (P=0.675).The Q value be- tween male (-0.26?0.15) and female(-0.27?0.17) was not statistically difference(P=0.697).No significant relation was found Q value with either sphere (r=0.057,P=0.068) or cylinder (r=0.044,P=0.156).Mean Q value of below 20 years old was maximal,-0.24,while over 40 years old was minimal,-0.36,and the difference were statistically significant (P=0.000).Conclusions Q value of cornea has negative shift with the increase of age,especially in over 40 years old.Q value of cornea has no relationship with left or right eyes,sex and refraction,but it is highly customized.