Sequential Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION)

A 68-year old woman with hypertension, obstructive sleep apnea and obesity was seen in neuro-ophthalmology consultation for vision loss in the right eye. She had right optic disc edema with a small optic disc hemorrhage a small, crowded optic disc in the left eye known as a "disc-at-risk" (Figure 1). Humphrey 24-2 SITA-Fast visual fields showed non-specific points of depression in the left eye (Figure 2). She had normal laboratory investigations including complete blood count (CBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and was diagnosed with right NAION. She lost vision in her left eye 2 weeks later and had new optic disc edema in the left eye with optic disc hemorrhages (Figures 3 and 4). Humphrey 24-2 SITA-Fast visual fields show a right superior altitudinal defect and inferior points of depression in the left eye (Figure 5). Repeat CBC, ESR, and CRP were normal and was diagnosed with sequential NAION. She was seen in follow-up 1 month later and had mild improvement in her vision in the right eye, but no change in her left eye. There was resolution of the optic disc edema and optic disc pallor in both eyes at that time (Figures 6 and 7). Humphrey 24-2 SITA-Fast visual fields were unreliable due to fixation losses and a high number of false positives (Figure 8). Optic coherence tomography (OCT) of the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC), which includes the ganglion cell layer and inner plexiform layer, showed inferior loss of the GCC corresponding to the superior visual field defect in the right eye and superior GCC loss corresponding to the inferior visual field defect in the left eye (Figures 9 and 10). [[Figure 1. Optic disc photos of both eyes demonstrating right optic disc edema and a left small, crowded optic nerve ("disc-at-risk"). Figure 2. Humphrey 24-2 SITA-Fast visual fields showing non-specific depressed points in the left eye above and below the horizontal. There are also non-specific depressed points in the right eye. Figure 3. Optic disc photos demonstrating right optic disc edema and new left optic disc edema with optic disc hemorrhages. Figure 4. Comparison of optic disc photos from the initial visit to the follow-up visit 2 weeks later. Figure 5. Humphrey 24-2 SITA-Fast visual fields show a right superior altitudinal defect and inferior points of depression in the left eye. Figure 6. Optic disc photos showing bilateral optic disc pallor. Figure 7. Optic disc photos from her previous visits shown for comparison. There has been resolution of the optic disc edema and optic disc pallor in both eyes. Figure 8. Humphrey 24-2 SITA-Fast visual fields were unreliable due to high false negatives and fixation losses. Figure 9. Optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL) shows mild thinning superiorly in both eyes and OCT macular ganglion cell analysis shows inferior ganglion cell complex (GCC) thinning in the right eye and superior GCC thinning in the left eye. Figure 10. The inferior ganglion cell complex (GCC) thinning in the right eye corresponds to the superior visual field defect and the superior GCC thinning in the left eye corresponds to the inferior visual field defect in the left eye. The previous reliable visual fields were used for this figure. ]]