Sparing of the temporal crescent in homonymous hemianopia and its significance for visual orientation

Abstract

Eleven patients with homonymous hemianopia of acute onset, and without any improvement within two months or more, were investigated for the disability caused by their visual field defect. Nine of them, with a complete and dense hemianopia (in four cases due to a purely occipital lesion), indicated that they were moderately to severely handicapped, at least initially. Two patients, however, were never really disabled by their visual field loss. From the beginning they never had collisions with people or objects, either in known or in unknown surroundings. Only when stationary, they sometimes 'overlooked' static objects immediately in front of them. In both patients the unpaired portion of the visual field, the 'temporal crescent', was partially preserved. The importance of this monocular visual field area for visual orientation, especially movement perception. will be discussed.