Vision restoration therapy: The U.S. experience

摘要

Background Vision restoration therapy (VRT) is a computer-based training program developed to improve visual function in patients with visual field defects from brain damage. By stimulating the border of the visual field defect, VRT attempts to improve function in areas of residual vision that may not be appreciated or that may represent areas of relative defect. Methods Patients with retrochiasmatic lesions and homonymous visual field defects were treated with a 6 module course of VRT. High resolution perimetry (HRP), a suprathreshold perimetry of the central 40 x 50 degrees, was obtained at baseline and after each module. The percent of stimuli detected in each perimetric mapping was recorded. When available, Humphrey automated perimetry results were compared. Age of patient, lesion location, and time from injury were recorded. Results More than 200 patients have been treated with VRT in the U.S., with more than 60 patients having completed the 6 module course. Two-thirds of patients had an improvement in their central field stimuli detection of >=5%, and approximately 80% of patients indicated subjective improvement in their visual function. Most patients had occipital infarctions. Time since injury did not correlate with the degree of field expansion. Examples will be provided. Conclusions VRT may be a useful rehabilitative intervention for some patients with visual field defects from retrochiasmal lesions. The mechanisms of improvement are debated.