Vision rehabilitation in homonymous hemianopia

Abstract

During our investigation into the structure of different visual field defects, five patients with long-standing homonymous hemianopia showed an unexpected improvement in sensitivity on the hemianopic side of their visual field during repeated measurements. The testing paradigm was then used in a training program to improve the patients’ detection and recognition sensitivity. Training resulted in further improvement in two patients until flicker sensitivity became equal to that of the corresponding area of the normal hemifield; it improved in the other three, but did not become equal. One of our patients learned to recognize flickering and nonflickering letters at 20 degrees eccentricity. His recognition sensitivity became equal to that of the normal side after 13 laboratory sessions carried out during a 12-month period.There was also an improvement in the Goldmann visual fields after three years of training. Since there had been no change in the clinical findings or in the subjective experience of space on the hemianopic side in seven years after his accident, the improvement is likely to have resulted from the training with flickering stimuli. We present this case as a preliminary report on the reappearance of form vision in homonymous hemianopia during training seven years after a vascular accident.