Adaptive-optics scanning laser ophthalmoscopy study of non-arteritic anterior ischemic optic neuropathy

To investigate the changes in cone photoreceptors in patients with non-arteritic anterior ischemic optic neuropathy (NAION).

Adaptive-optics scanning laser ophthalmoscopy (AO-SLO) was performed in patients with NAION and healthy participants. Acute NAION was defined as a disease duration of <2 months, whereas chronic NAION was defined as a duration of >2 months. We analyzed four quadrants (superior, inferior, nasal, and temporal with respect to the central fovea of the macula) of the cone layer images at 2.4° × 2.4° collected at 3° eccentricity. Patients with NAION were further examined by using optical coherence tomography (OCT).

Significant differences were observed in peripapillary retinal nerve fiber layer and ganglion cell layer thicknesses between the normal and affected eyes (P < 0.05). The AO-SLO data of patients with monocular NAION showed no statistical differences in the density, regularity, and dispersion of cone cells in the superior, inferior, nasal, and temporal quadrants (P > 0.05). No significant differences were noted in the density among the healthy, acute NAION, and chronic NAION groups (P > 0.05).

AO-SLO showed cone integrity in patients with NAION. From a microscopic perspective, NAION might not affect cone photoreceptors.