The preserved temporal crescent: the clinical implications of an "endangered" finding.

Sixteen consecutive patients with a partially or completely preserved temporal crescent (PTC) in right or left eye were identified by Goldmann kinetic perimetry. PTC etiologies were stroke, birth injury, trauma, aneurysm, and migraine. PTC eludes detection by automated static perimetry of the central visual field, but its ascertainment with Goldmann perimetry usually implies contralateral occipital lobe ischemia sparing a small portion of anterior primary visual cortex.