Comparison of Optic Nerve Head Morphology in Patients with Primary Open Angle Glaucoma and Non-Arteritic Anterior Ischemic Optic Neuropathy

The aim of this study was to assess damage to retinal ganglion cells (RGC) and morphology of the optic nerve head (ONH) in patients with primary open angle glaucoma (POAG) and non-arteritic anterior ischemic optic neuropathy (NAION). The study included three groups of patients, as follows: 40 eyes with POAG, 40 eyes with NAION and 40 eyes with refraction anomaly. All patients underwent standard automated perimetry and analysis of ONH topography by using confocal scanning laser ophthalmoscopy (CSLO)-HRT II. Visual field defects such as decreased retinal sensitivity prevailed in the eyes with POAG, whereas in the eyes with NAION they were mostly manifested as concentrically narrowed visual field and quadrant excesses. Topographic ONH alterations, examined by HRT II, showed the same number of sectors to be affected in the eyes with POAG and NAION. A larger number of sectors in the upper part of ONH were affected in the eyes with NAION. Optic disc morphology differed significantly between the eyes with POAG and NAION by a higher rate of neuroretinal rim thinning and higher mean cup depth in the POAG group.