The Discussion Of The Significance Of Diffusion Kurtosis Imaging In The Early Diagnosis Of Primary Open Angle Glaucoma

Objective:discussing the significance of early stage diagnosis of primary open angle glaucoma by functional magnetic resonance imaging(fMRI)Methods : Recruited the population of primary open angle glaucoma suspect(POAGS),as POAGS group as well as primary open angle(POAG)patients,healthy controls(HC)people,as POAG group and HC group separately,f MRI and basic examination of ophthalmology including Optical coherence tomography(OCT),cup to disc radio(CDR),visual activity(VA),intraocular pressure,(IOP),Visual field examination(VF),Ultrasound biomicroscopy(UBM.The diffusion kurtosis imaging(DKI)took place at the retrobulbar optic nerve.Parameters including fractional anisotropy(FA),mean diffusivity(MD),mean kurtosis(MK),axial kurtosis(KA),radial kurtosis(KR),calculated the medical reference value range according the HC group.All the subjects underwent difference test,correlation analysis and receiver operating characteristic(ROC)curve analysis,used Kappa test to analyse the consistency between medical reference value range and receiver operating characteristic analysis among POAGS group.Results :(1)The medical reference value range of FA,MK,KR,KA,MD were(0.478-0.772,0.600-1.367,0.086-3.704,0.429-0.767,0.830-1.687).There were significant difference of FA,MK,KR,KA,MD between POAG group and HC group(P<0.05),FA,MK,KR,KA of POAG group is higher,MD of POAG group is lower,the area under curve of MK is highest,which is 0.920,the sensitivity is 90%,specificity is 80% when MK is 0.788,the cut-off point of FA is 0.487,which possess 60% sensitivity and 100% specificity;(2)FA,MK,KR and KA values in POAG group were significantly positive correlated with the mean deviation(MD)of visual field(r=0.770,r=0.650,r=0.624,r=0.502,P<0.05),MD values were significantly negative correlated with the MD of visual field(r=-0.488,P<0.05).FA,MK,KR and KA values in POAG group were significantly positive correlated with the retinal nerve fibre layer(RNFL)thickness(r=0.826,r=0.837,r=0.662,r=0.528,P<0.05),MD values were significantly negative correlated with the RNFL thickness(r=-0.450,P<0.05);(3)There were significant difference of FA,MK,KR,KA,MD between POAGS group and POAG group(P<0.05),FA,MK,KR,KA of POAGS group is higher,MD of POAG group is lower,the area under curve of MK is highest,which is 0.950,the sensitivity is 100%,specificity is 80% when MK is lower than 0.680,the sensitivity is 100%,specificity is 95% when FA is lower than 0.442.To test the consistency between medical reference value range and ROC curve,MK was 0.026,FA was 1.Conclusion:(1)Compared with HC group,DKI parameters in POAG group changed significantly,they can be used to differentiate these two groups.(2)The kurtosis of water molecular diffusion may changing accompany the progressing of the degree of disease,MK,KA,KR,FA became lower,MD became higher.(3)DKI parameters can be used as an evaluation method of optic nerve injury in POAGS patients,FA and MK may be the best among them,which possess high significance in diagnosing the early stage of POAG.