Arteritic anterior ischemic optic neuropathy (A-AION)

A 77-year-old man presented with acute, painless, decreased vision in the right eye (OD) for one day. Past medical history was significant for hypertension. He had a few recent episodes of transient blackouts of vision OD, increased generalized fatigue, a right-sided headache with associated tenderness of the right temple, and pain while chewing his food for the past few weeks. He denied recent trauma, neck pain, or any other significant symptoms. On external examination, there was temporal tenderness on the right and the temporal artery was nodular to palpation. Best-corrected visual acuity was 20/400 OD and 20/40 in the left eye (OS). Pupils measured 4 mm in the dark and 2 mm in the light in both eyes (OU) with a right relative afferent pupillary defect. Extraocular motility was full and the eyes were orthotropic in all positions of gaze. Humphrey visual field (24-2) using a stimulus V showed general depression OD and scattered non-specific defects using a stimulus III OS. Anterior segment exam was within normal limits OU. Dilated fundus examination revealed pallid disc edema OD (see Fig. 7.1). The left fundus examination was unremarkable. Fluorescein angiography showed patchy delayed choroidal hypoperfusion OD and normal retinal and choroidal perfusion OS. Erythrocyte sedimentation rate (ESR) was elevated at 73 mm/hr and a C-reactive protein (CRP) was also elevated at 6.4 mg/L. A temporal artery biopsy revealed multinucleated giant cells (see Fig. 7.2) and inflammatory infiltrates consistent with giant cell arteritis (GCA).