Hypothesis: Patients with hemianopic field defects (HFD) might benefit from reading text in vertical orientation if they place the text in the seeing hemifield along the vertical midline.
Methods: We assigned 21 patients with HFD randomly to either vertical or horizontal reading training. They trained reading single lines of texts from a computer screen at home for 2 × 30 min/day, 5 days/week, for 4 weeks. The main outcome variable was reading speed (RS) during reading standardized paragraphs of printed text (IReST) aloud. RS was assessed before training (T1), directly after training (T2) and 4 weeks later (T3). Quality of life (QoL) was assessed by Impact of Visual Impairment (IVI) questionnaire.
Results: Vertical training improved RS in the vertical direction significantly. Only patients with right HFD benefited. Horizontal training improved RS in horizontal diection significantly, but much more in patients with left than in those with right HFD. Both effects remained stable at T3. RS during training at the computer improved highly significantly and correlated strongly with RS of printed text (Pearson r= > 0.9). QoL: Vertical training showed a statistically significant improvement in the complete IVI-score, patients with right HFD in the emotional IVI-score.
Conclusions: The improvements of RS were specific for the training. The stable effect indicates that the patients can apply the newly learned strategies to everyday life. The side of the HFD plays an essential role: Left-HFD patients benefitted from horizontal training, right-HFD patients from vertical training. However, the vertical RS did not reach the level of horizontal RS. The study was registered in the German Clinical Trials register (DRKS-ID: DRKS00018843).
Keywords: Hemianopic field defect; Hemianopic reading disorder; Homonymous hemianopia; Reading training; Text orientation; Vertical reading.