Recovery of visual field defects: A large clinical observational study using vision restoration therapy

• Published in: Restorative neurology and neuroscience Vol. 25; no. 5-6; pp. 563 - 572
• Main Authors: Mueller, Iris, Mast, Henning, Sabel, Bernhard A.
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2007
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Child; Female; Hemianopsia - physiopathology; Hemianopsia - rehabilitation; Humans; Male; Middle Aged; Observation - methods; Ophthalmoscopes; Photic Stimulation - methods; Reaction Time - physiology; Recovery of Function - physiology; Therapy, Computer-Assisted - methods; Treatment Outcome; Visual Field Tests - methods; Visual Fields - physiology; visual training; hemianopia; visual field deficits; Vision restoration; plasticity; brain damage; neurorehabilitation
• ISSN: 0922-6028; 1878-3627
• DOI: 10.3233/RNN-2007-00412

Purpose: In small experimental trials, vision restoration therapy (VRT), a home-based rehabilitation method, has shown to enlarge the visual field and improve reaction times in patients with lesion involving the CNS. We now evaluated the outcome of VRT in a large sample of clinical patients and studied factors contributing to subjective and objective measures of visual field alterations. Methods: Clinical observational analysis of visual fields of 302 patients before and after being treated with computer-based vision restoration therapy for a period of 6 months at eight clinical centers in central Europe. The visual field defects were due to ischemia, hemorrhage, head trauma, tumor removal or anterior ischemic optic neuropathy. Primary outcome measure was a visual field assessment with super-threshold perimetry. Additionally, conventional near-threshold perimetry, eye movements and subjective reports of daily life activities were assessed in a subset of the patients. Results: VRT improved patients' ability to detect super-threshold stimuli in the previously deficient area of the visual field by 17.2% and these detection gains were not significantly correlated with eye movements. Notable improvements were seen in 70.9% of the patients. Efficacy was independent of lesion age and etiology, but patients with larger areas of residual vision at baseline and patients > 65 years old benefited most. Conventional perimetry validated visual field enlargements and patient testimonials confirmed the improvement in every day visual functions. Conclusions: VRT improves visual functions in a large clinical sample of patients with visual field defects involving the CNS, confirming former experimental studies.