Abstract
Purpose :
Purpose: We have shown1 that patients with hemianopic field defects (HFD) can increase their reading speed (RS) significantly by reading text in vertical orientation and placing the text in the seeing hemifield along the vertical midline, but the underlying mechanisms was not yet analyzed. We hypothesize that the improvement of RS is due to specific eye movement (EM) mechanisms developed during the training. These new data will be presented here.
Methods :
Methods: 21 patients with HFD (onset =>6 months) were randomly assigned to either vertical or horizontal reading training. They trained reading texts, presented as a single line at a time, from a computer screen at home for 2x30 minutes/day, 5 days/week, for 4 weeks. Eye movements (EM) were recorded during reading short standardized sentences aloud, before training (T1), directly after training (T2) and 4 weeks later (T3). Reading speed (RS) was assessed during reading standardized paragraphs of printed text to assess the transfer to everyday life.
Results :
Results: EM variables showed highly significant negative correlations with RS, dependent on the side of the HFD. In right HFD (n=10), the number of forward saccades RS showed a highly significant negative correlation with RS (T1: Pearson r=-0.87, p<0.01, T2: r=-0.94, p<0.01). In left HFD, there was a highly significant negative correlation of the number of saccades during the return sweep with RS (T1: r=-0.83, p<0.01, T2: r=-075, p<0.05). Fixation duration showed a less pronounced, significant negative correlation with RS in all patients (T1: r=-0.66, p=0.002, T2: r=-0.56, p<0.02). The training effects remained stable at T3.
Conclusions :
Conclusions: The improvement of RS was specific for the training and the side of the HFD. Right HFD patients benefited from vertical reading training by reducing the number of forward saccades. However, the vertical RS did not reach the level of horizontal RS. Onset of training earlier after the lesion and a longer training period might enhance the effect. Left HFD patients benefited from horizontal training mainly by reducing the number of saccades during the return sweep. The fact that the patients trained on a screen and that RS was assessed during reading printed paragraphs of text as well as the stable effect after end of training indicates that the patients can apply the newly learned strategies to everyday life.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.