Retinal nerve fiber layer thickness in nonarteritic anterior ischemic optic neuropathy: OCT characterization of the acute and resolving phases.

BACKGROUND: To evaluate longitudinal changes in retinal nerve fiber layer (RNFL) thickness in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography (OCT).

METHODS: Prospective, observational case series study. Sixteen eyes from 15 consecutive patients affected with NAION were analyzed. The fellow unaffected eyes served as controls. Patients were divided into three different study groups: (1) patients with visual field (VF) defect confined to the inferior hemifield (five eyes), (2) patients with diffuse VF loss (seven eyes), and (3) patients with central or centrocecal scotoma (four eyes). The main outcome was peripapillary RNFL thickness measurement by Stratus-OCT.

RESULTS: In group 1, OCT demonstrated RNFL involvement limited to the temporal , superior and nasal optic disc quadrants, both in acute and athophic stages. Diffuse RNFL damage involving all quadrants around the disc was observed in group 2 patients. Group 3, by contrast, revealed RNFL atrophy limited to the superior and temporal sectors of the disc.

CONCLUSIONS: OCT can identify different patterns of RNFL involvement specific to different classic VF defects in eyes with NAION. Our results corroborate previous histologic findings in optic nerves affected with NAION.