A 29-year-old woman underwent brain MRI for increasing frequency of migraine headaches. The MRI report recommended further evaluation for septo-optic dysplasia. The patient reported no visual deficits. Her examination showed normal visual acuities, color vision, pupillary function, and a normal optic disc in the right eye with mild temporal disc pallor in the left eye. Automated perimetry revealed an incongruous left homonymous hemianopia (Fig. 1). Optical coherence tomography (OCT) showed thinning of the retinal nerve fiber layer to 60 µm in the right eye and 54 µm in the left eye. There was ganglion cell layer thinning in a hemianopic pattern with temporal thinning in the right eye and nasal thinning in the left eye. This corresponded with the left homonymous hemianopia
