Objective To investigate the effect of orthokeratology(OK)lens decentration on peripheral retinal defo-cus in myopic eyes.Methods Totally 154 patients(234 eyes)continuously wearing OK lenses for one month or more were recruited in this study.According to the location of defocus rings in corneal topography,these eyes were divided into the centration group(118 eyes)and the decentration group(116 eyes).Peripheral retinal defocus data of each patient was collected by multispectral refraction topography,including total refraction difference value(TRDV),refraction difference value at 15°(RDV-15),refraction difference value at 30°(RDV-30),refraction difference value at 45°(RDV-45),superior refraction difference value(RDV-S),inferior refraction difference value(RDV-I),temporal refraction difference value(RDV-T)and nasal refraction difference value(RDV-N).An independent sample t-test was used to compare the differ-ences in these parameters between the two groups,and multivariate correlation analysis(generalized estimating equation,GEE)was conducted to analyze the relationship between clinical parameters and the amount of peripheral retinal defocus within the group.Results The RDV-N of patients in the decentration group was significantly lower than that in the cen-tration group(t=2.668,P=0.008),and there were no significant differences in other parameters(all P＞0.05).GEE showed that age was the determinant of RDV-S,and they were positively correlated;steep K was the determinant of RDV-I,and they were negatively correlated;gender was the determinant of RDV-T,and female OK lens wearers showed less RDV-T;the determinants of RDV-N include the alignment of OK lens,eye distribution and age,among which,RDV-N was positively corrected with age,and RDV-N of the left eyes was significantly superior to that of the right eyes.Conclusion Subclinical decentration of the OK lens may result in better RDV-N of myopia patients.The peripheral retinal defocus is influenced by factors such as age,gender,steep K,amount of decentration and eye distribution of OK lens wearers.