To compare the pattern of macular ganglion cell inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) changes in moderate to severe primary open-angle glaucoma (POAG) with non-arteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography (OCT) auto-segmentation.

A total of 138 eyes (42 eyes with chronic unilateral NAION and their unaffected fellow eyes, 32 eyes of 32 moderate to severe glaucoma patients, and 22 eyes of 22 healthy normal subjects) underwent neuro-ophthalmologic examinations and spectral-domain OCT in a cross sectional study at a single academic institution. GCIPL and total retinal thicknesses were calculated in eight quadrants corresponding to the Early Treatment Diabetic Retinopathy Study areas in addition to peripapillary RNFL thickness.

Peripapillary RNFL, total macula, and GCIPL were significantly thinner in NAION and POAG eyes compared to unaffected fellow eyes of NAION and control age-matched healthy eyes in all sectors (all P values< 0.001). There was no significant difference in peripapillary RNFL, total macula, and outer GCIPL thicknesses between the affected eyes of the patients with NAION and glaucoma patients. However, the inner GCIPL was significantly thinner in NAION compared to POAG after adjusting for age, sex, and mean deviation of the visual field (P=0.001).

Patients with NAION show a more decreased inner GCIPL thickness, (closer to the fovea) compared with those with POAG.