Utility of optical coherence tomography in the evaluation of monocular visual loss related to retinal ischemia

• Disrupted macular architecture by OCT supports a diagnosis of retinal artery occlusion.
• OCT hyper-reflectivity of the plexiform layers characterize an acute retinal artery occlusion.
• The outer nuclear layer of the retina is preserved in an acute retinal artery occlusion.
• Subtle retinal ischemia and swelling may be detected by OCT.

We report four patients with monocular visual loss for whom optical coherence tomography (OCT) was helpful in distinguishing the sequelae of retinal artery occlusion from those of primary optic neuropathy. Determinations of the peripapillary retinal nerve fiber layer (RNFL) thickness as well as macular retinal layer thicknesses and architecture were used. The major findings in our patients show that changes in the inner retinal layers (including ganglion cell and inner plexiform layer) with disruption of normal macular architecture supports a diagnosis of retinal artery occlusion. Our results support the use of OCT imaging for patients with monocular visual loss of uncertain etiology; macular imaging as well as peripapillary RNFL thickness measurement can be helpful in differentiating primary retinal disease or ischemia from primary disorders of the optic nerve.