Abstract
<title>Abstract</title> <p>Purpose: This study aimed to characterize the clinical presentation of patients suffering from non-arteritic anterior ischemic optic neuropathy (NAION) with inferior optic disc ischemia and superior visual field defects, and to follow the local, longitudinal changes in optic disc structure and microvascular parameters. Methods: This study included 22 patients (24 eyes) diagnosed with NAION. From optical coherence tomography angiography (OCTA) data, measurements were extracted for macular ganglion cell complex (GCC) thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, and radial peripapillary capillary (RPC) density. After comparing the obtained measurements, the study assessed structure-function relationships and regional differences. Results: 91.7 % of the patients have a small optic disc configuration. During the follow-up, while the best-corrected visual acuity (BCVA) improved significantly from the baseline (P = 0.003), the visual field parameters did not recover to a degree of statistical significance (P > 0.05). Both GCC and RNFL thicknesses, as well as RPC blood flow density, declined significantly from baseline (all P < 0.01). Compared with the superior section, the inferior section performed a thinner GCC and worse RNFL atrophy, as well as a lower RPC blood flow density (P < 0.01). Sub-quadrant analysis revealed a highly significant positive correlation between local microvascular perfusion and corresponding RNFL thickness. Conclusion: In this NAION subtype, a highly synchronous progressive loss of microvascular perfusion and of neural structures happens in the ischemic inferior region. The relative sparing of temporal microcirculation is the reason that central vision may recover and visual field defect may persist.</p>