Figures 1-2. This is a Humphrey's visual field FROM a man who comes in for a neuroophthalmic eye exam.
Questions and Answers
1. Describe the visual field defect. Answer: This is an incongruous bitemporal visual field defect that respects the vertical midline.
2. What is the most likely cause of such a visual field defect? Answer: A sellar chiasmal mass such as a pituitary adenoma is the most likely cause of such a visual field defect.
3. What else can cause this visual field defect? Answer: Causes of non chiasmal pseudo bi-temporal field defects include, tilted optic discs, sector retinitis pigmentosa, cecocentral scotomas, papilledema, optic nerve head drusen, overhanging eyelids, drugs such as chloroquine, bilateral retinal detachments, and hysteria.
4. What type of nystagmus can be associated with this field defect? Answer: See-saw nystagmus which is a conjugate clockwise then counterclockwise rotation of the eyes FROM 150 to 300 cycles per minute. There is elevation of the intorting eye and depression of the extorting eye which appears as if the eyes are see-sawing up an down.