Rehabilitation of hemianopic alexia in patients with postgeniculate visual field disorders

Abstract

A new systematic training procedure for patients with hemianopic alexia resulting from postchiasmatic visual field defects (VFD) was evaluated in 56 patients. Reading performance was measured with standardised reading tests before and after treatment and at a follow-up after treatment (mean follow-up interval, 22 months). In addition, visual fields were mapped perimetrically in all patients before and after training and at follow-up. Significant improvements in reading time and reading errors were obtained during the treatment phase, which remained stable at long-term follow-up. In contrast, only minor, though significant, increases in visual field size were obtained during training. Multiple baseline designs in four patients revealed that improvements in reading were training-dependent and not related to spontaneous recovery, measurement variability or other therapies performed partially in parallel to reading training. A significant improvement in reading could be reached within about 14 (range 5–40) 40-min treatment sessions. It is concluded that the new training procedure can lead to a significant and stable improvement of reading in patients with hemianopic alexia, and thus to a better compensation of this disorder in daily living.