Preliminary Observation Of Optic Disc Perfusion And Structural Changes With OCTA In Non-arteritic Anterior Ischemic Optic Neuropathy

Objective:To investigate the difference of vessel density in all sectors of the macular region of patients with non-arteritic anterior ischemic optic neuropathy(NAION)and healthy controls(HC)in different stages with optical coherence tomography angiography(OCTA).Meanwhile,qualitative compare the vessel density of the optic disc in unilateral involved eyes,fellow eyes in NAION patients and healthy controls to obtain the perfusion of the optic disc and macula in NAION patients in different stages and its correlation with the structure and visual function.Methods:This study was a single-center,prospective observational study including NAION patients who visit the Ophthalmology outpatient department of Peking Union Medical College Hospital from November 2017 to May 2018,General eye examination,visual field examination,and OCTA were performed to obtain blood flow in the optic and macular area and structural information.Ultimately group and regional analysis is made to carry out overall differences of blood flows and structures and the correlations with visual function.Results:The superficial vessel density in macular area of NAION patients was significantly lower than that in the HC group(p<0.01)as a whole and in different stages.The vessel density of unilateral involved eye was significantly lower than that in the fellow eye and HC group(p<0.01),while no difference was found in fellow eye and HC group and also for deep vessel density.There was no significant difference in the superficial vessel density in macular area between patients in acute phase and HC group.The difference was gradually significant with the progress of the disease to the chronic phase.The ganglion cell complex(GCC)thickness,gross loss of volume(GLV),focal loss of volume(FLV)and retinal nerve fiber(RNFL)in acute and chronic phase were significantly lower than those of healthy controls,corresponding to the decrease of superficial vessel density in macular area while no difference was found in fovea at all times(p>0.1).There was a correlation between superficial vessel density in macular area and GCC thickness,FLV,GLV and mean deviation(md)(r?0.606,p<0.01).Patients in different phases have a linear relationship between the superficial vessel density of the macula in the inferior hemispheric and temporal side.Some patients were followed by subsequent spontaneous recovery in the superficial vessel density in macular area.Conclusion:OCTA is a new technology of angiography which has advantages over the traditional ones.It can observe the vascular morphology and blood vessel density of the optic disc,peripapillary and macular area rapidly and noninvasively.We can detect the changes of vessel density of macular and optic disc regions in NAION patients and its correlation with structural and visual function which will play an important role in exploring the pathogenesis and treatment of NAION.