Follow-up of nonarteritic anterior ischemic optic neuropathy with optical coherence tomography angiography

Abstract Background To analyze the blood flow changes of radial peripapillary capillaries (RPC) and macula with time procession in patients with non-arteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCT-A).Methods A total of 21 affected eyes and 19 unaffected eyes from 21 NAION patients, and 40 eyes of 20 healthy individuals were included. Assessments of BCVA, CFP, SD-OCT, and OCT-A were performed on NAION patients at enrollment and at 1-2 weeks, 1-2 months, and 3-6 months post-enrollment. Measures of the thickness of peripapillary retinal nerve fiber layer (wRNFL) and macular ganglion cell complex (wGCC) of the whole image in SD-OCT, vessel density of RPC (wRPC) and superficial and deep vascular complexes (wSVD, wDVD) in the whole image of OCT-A, and their superior- and inferior-hemi values (s/iRNFL, s/iGCC, s/iRPC, and s/iSVD) were assessed.Results Compared to healthy controls, wRPC (p<0.001) and wDVD (P=0.001) were significantly lower in affected eyes at baseline, and there was no significant difference in wSVD (p>0.05). The wRPC and wSVD values of affected eyes were significantly decreased at follow-up time points of 1-2 and 3-6 months compared to baseline (p=0.001, p=0.000; p=0.000, p=0.000). The sRPC values were significantly lower than iRPC at 1-2/3-6 months (p=0.001, p=0.000), and sSVD values were lower than iSVD at 1-2 months (p=0.010). Statistically significant correlations were found between wRPC and wRNFL values at 3-6 months (r=0.626, p=0.022), between wSVD and wGCC at 1-2 weeks and 1-2 months (r=0.570, r=0.436; p=0.007, p=0.048).Conclusion OCT-A revealed a sectorial reduction in vessel density in RPC and macula with the disease progression of NAION from acute to atrophic stages, a classification associated with structural deficits.