AIM: To investigate the related factors of orthokeraology(ortho-K)decentration.

METHODS: Within a prospective study, 88 eyes of 88 patients who visited to our center between July 2014 and December 2016 were enrolled. To verify the possible role of the spherical equivalent(SE), the corneal astigmatism(CA), e value, steep K, flat K, front curvature asymmetry index(SIf)and age in the ortho-K location prediction.

RESULTS: This study included 24 eyes of grade Ⅰ decentration, 26 eyes with grade Ⅱ, 25 eyes with grade Ⅲ, and 13 eyes with grade Ⅳ, by which based on the decentration system that published by our team. One-way ANOVA showed that there was statically significant difference of SE, Ks and Kf in different grading groups(P<0.05). Multiple linear regression analysis showed SE was negatively correlated with the decentration(P<0.01). The others factors such as the CA, e, Ks, Kf, SIf, age has weak correlation with the ortho-K decentration.

CONCLUSION: The SE might be the main factor which lead to the ortho-K decentration.