Long-term learning of visual functions in patients after brain damage

Abstract

Purpose Systematic vision restoration training has been shown to improve the detection performance of brain-damaged patients with visual-field defects. So far, patients have been trained daily up to 6 months. We wished to determine whether intensive long-term training of 12 months further increases visual detection abilities. Methods Retrospective comparison of 17 patients with visual-field defects using vision restoration training for 12 months with a group of patients training for 6 months. Computer-based home training was completed for 6 months (about 195,000 stimuli presentations) or for 12 months (about 390,000 stimuli presentations). Visual fields were measured at baseline with Rodenstock Perimat 206 (monocular) at 90° eccentricity and at 54° eccentricity with high resolution perimetry (HRP) (binocular) after 6 months (post-6) and after 12 months (post-12) of training. Results Near-threshold perimetry revealed minor training effects, beyond 6 months, of 3.5% ( p = 0.099) in the right eye and of 1.5% ( p = 0.57) in the left eye. No effects of long-term training were evident in above threshold testing (0.8% detection improvement, n.s.). Conclusions Learning to detect above-threshold stimuli in patients with post-retinal lesions is completed after 6 months of practice with only marginal improvements thereafter. Near-threshold testing reveals that peripheral areas of the visual-field benefit from long-term training even if they are not trained.