Correlation factors in changes of rear sclera in high myopia evaluated by color Doppler ultrasound

Objective:To explore the morphological changes of rear sclera in myopia and the relation among the length of eye axis and the degree of myopia and hemodynamic changes.Methods:Morphology of rear sclera in 26 cases of normal control(NC),36 cases of light and medium myopia(LAMM) and 51 cases of high myopia(HM) were observed by color Doppler ultrasound.And ophthalmic artery(OA),central retinal artery(CRA) and posterior ciliary artery(PCA) in NC group,17 cases of LAMM group and HM group were measured.Results:The length eye axis in LAMM group and HM group had positive correlation with the degree of myopia.The linear regression equation between them was Y=-3510.3+1668.1X,R=0.9432,P0.0001.The morphological changes of rear sclera in both LAMM group and HM group had significant difference compared with that in NC group(P0.0001).The flow parameters of OA in each group had no significant difference compared with that in other groups(P0.05).The systolic,diastolic and mean flow velocity of CRA,PCA in HM group decreased significantly(P0.05),but the resistent index(RI) of CRA in HM group increased significantly(P0.05).The flow parameters in LAMM group had no significant difference as compared with that in NC group(P0.05).Conclusion:The insufficient blood supply to retina is an important factor that contributes to the occurrence and development of the pathological changes of retina in high myopia.The type of morphological changes in rear sclera shows significant correlation with the length of eye axis,the degree of myopia and hemodynamic changes.