Differences between Non-arteritic Anterior Ischemic Optic Neuropathy and Open Angle Glaucoma with Altitudinal Visual Field Defect

Abstract

PurposeTo investigate the differences in retinal nerve fiber layer (RNFL) change and optic nerve head parameters between non-arteritic anterior ischemic optic neuropathy (NAION) and open angle glaucoma (OAG) with altitudinal visual field defect.MethodsSeventeen NAION patients and 26 OAG patients were enrolled prospectively. The standard visual field indices (mean deviation, pattern standard deviation) were obtained from the Humphrey visual field test and differences between the two groups were analyzed. Cirrus HD-OCT parameters were used, including optic disc head analysis, average RNFL thickness, and RNFL thickness of each quadrant.ResultsThe mean deviation and pattern standard deviation were not significantly different between the groups. In the affected eye, although the disc area was similar between the two groups (2.00 ± 0.32 and 1.99 ± 0.33 mm2, p = 0.586), the rim area of the OAG group was smaller than that of the NAION group (1.26 ± 0.56 and 0.61 ± 0.15 mm2, respectively, p < 0.001). RNFL asymmetry was not different between the two groups (p = 0.265), but the inferior RNFL thickness of both the affected and unaffected eyes were less in the OAG group than in the NAION group. In the analysis of optic disc morphology, both affected and unaffected eyes showed significant differences between two groups.ConclusionsTo differentiate NAION from OAG in eyes with altitudinal visual field defects, optic disc head analysis of not only the affected eye, but also the unaffected eye, by using spectral domain optical coherence tomography may be helpful.

Diagnosis of ischemic optic neuropathy caused by dissection of the internal carotid artery

“…Our patient had the symptom of the decreased visual acuity and quadrant visual field defect, which were typical in the ION due to the ischemia setting of optic nerve. [ 7 ]…”

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

“…Han et al demonstrated that the inferotemporal rim loss usually was more pronounced in glaucoma patients, and therefore superior visual fi eld defects were more expressed. Th erefore, inferior visual fi eld defects were more common in the NAION group 25 . Other authors found thickening rather than thinning of the prelaminar neural tissue to occur fi rst in the early stage of glaucoma.…”

Nonarteritic anterior ischemic optic neuropathy: cause, effect, and management

“…Some recent studies have demonstrated the use of OCT in the assessment, diagnosis, and management of NAION. 6 , 20 Findings include increased peripapillary choroidal thickness associated with optic disc edema and subretinal fluid on spectral domain OCT (SD-OCT) and macular ganglion cell inner plexiform layer thinning associated with VF defect in frequency domain OCT (FD-OCT). 6 , 21 Another study found that NAION affected neither the cup-to-disc ratio nor alpha or beta zone of parapapillary atrophy.…”

“… 6 , 20 Findings include increased peripapillary choroidal thickness associated with optic disc edema and subretinal fluid on spectral domain OCT (SD-OCT) and macular ganglion cell inner plexiform layer thinning associated with VF defect in frequency domain OCT (FD-OCT). 6 , 21 Another study found that NAION affected neither the cup-to-disc ratio nor alpha or beta zone of parapapillary atrophy. 22 Ganglion cell layer plus inner plexiform layer (GCL+IPL) thinning has been shown to be better than retinal nerve fiber layer (RNFL) thinning in indicating early structural loss in NAION.…”