The most common cause of binocular TVL is the homonymous hemianopic defect caused by migrainous visual aura. The patient typically notes a small scotoma in homonymous portions of the visual field, surrounded by jagged, luminous, shimmering edges. The scotoma enlarges over several minutes, sometimes to a complete homonymous hemianopia, then gradually disappears. The vision typically returns to normal within 20–30 minutes (the aura may be as short as 5 minutes; it is always less than 1 hour). The visual aura is usually followed by a headache, although some patients may experience the typical aura without headache (previously termed acephalgic migraine). The patient’s vision is completely normal between episodes, and the visual phenomena typically change sides. Evaluation of migraine is discussed in Chapter 12.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.