Previous Branch Retinal Artery Occlusion

This is a typical case of an old branch retinal artery occlusion in a 64 year old woman presenting with persistent monocular vision loss. She had sudden onset of painless vision loss in the inferior field of her left eye approximately one year prior. Her past medical history was significant for atrial fibrillation on warfarin, hypertension, dyslipidemia and morbid obesity. There was no previous use of amiodarone or phosphodiesterase inhibitors. On examination she had visual acuity 20/25+2 (OD) and 20/60-1 (OS), improving with pinhole to 20/30. Color vision was normal in both eyes. Visual fields by confrontation were abnormal in the inferior field of the left eye only. Ocular motilities were full. Fundoscopy revealed attenuation of the superior branch of the left retinal artery. Humphrey visual fields (24-2 SITA Fast) showed an inferior altitudinal defect in the left eye (Figure 1). Optos fundoscopic photography confirmed an old superior branch retinal artery occlusion (BRAO) with superior segmental atrophy of the left optic nerve and attenuation of the arteries superiorly (Figure 2a-c). Optical coherence tomography (OCT) of the optic nerve head was performed and showed loss of retinal nerve fiber layer (RNFL) superiorly in the left eye (Figure 3). Spectralis OCT of the retina demonstrated retinal thinning in the same distribution (Figure 4). On vertical cuts of the retinal OCT, thinning and loss of normal stratification of the inner retinal layers was evident in the superior retina of the left eye (Figure 5). The final diagnosis was superior BRAO OS with chronic changes seen on OCT. Vertical-cut OCT was important in confirming the superior distribution of retinal changes. The OCT findings helped to differentiate BRAO from NAION, which can also cause an altitudinal visual field defect (Figure 6), but leads to atrophy of the ganglion cell complex only (Figure 7).