Macular density alterations in myopic choroidal neovascularization and the effect of anti-VEGF on it

AIM:To analyse macular microvascular alterations in myopic choroidal neovascularization(m CNV)and the efficiency of anti-vascular endothelial growth factor(antiVEGF)therapy for m CNV by optical coherence tomography angiography(OCTA).METHODS:A total of 123 patients were included in this retrospective study,divided into m CNV group,high myopia(HM)group,and normal group at the Affiliated Eye Hospital of Wenzhou Medical University from January 2017 to January 2019.Superficial vessel density,deep capillary density,foveal avascular zone(FAZ)area,A-circularity index(AI)and vessel density around the 300μm width of the FAZ region density(FD)and the area of choroidal neovascularization(CNV)lesion(only for m CNV group)were measured on 3×3 mm2 OCTA images.FAZ area was corrected for axial length.Central macular thickness(CMT)was measured on OCT in m CNV group.Compared the parameters on OCTA of 3 groups and pre-anti-VEGF and post-anti-VEGF at 1,2,3,and 6 mo follow-up in m CNV group.RESULTS:There were significant differences among 3 groups in superficial vessel density,deep capillary density and FD(P<0.05).FAZ area in HM group was smaller than normal group(P<0.05),but there was no significant difference between m CNV group and the other two group.AI increased in m CNV group(P<0.05).The mean CMT,area and flow area of CNV lesion decreased after treatment(P<0.05),while vessel density and FAZ didn’t change.The mean CMT,area and flow area of CNV lesion statistically decreased after anti-VEGF treatment in m CNV group(P<0.05),while superficial vessel density,deep capillary density and FAZ area,AI and FD didn’t change.The mean reduction ratio of lesions was 50.32%(7.07%to 100%).Lesion regression 100%was observed in 2 cases(4.88%).There was a negative correlation between the CNV lesion area and reduction ratio(r=-0.380,P=0.042)and the flow lesion area and reduction ratio(r=-0.402,P=0.030).CONCLUSION:Macular vessel density decreases,FAZ turns smaller and more irregular in m CNV eyes.AntiVEGF therapy is efficient for m CNV without affecting vessel density and FAZ,but it is unable to completely eliminate CNV lesions in most cases.The bigger m CNV lesions have lower reduction ratio.