Recovery of visual fields in brain-lesioned patients by reaction perimetry treatment

The efficacy of treatment in hemianopic patients to restore missing vision is controversial. So far, successful techniques require laborious stimulus presentation or restrict improvements to selected visual field areas. Due to the large number of brain-damaged patients suffering from visual field defects, there is a need for an efficient automated treatment of the total visual field.

A customized treatment was developed for the reaction perimeter, permitting a time-saving adaptive-stimulus presentation under conditions of maximum attention. Twenty hemianopic patients, without visual neglect, were treated twice weekly for an average of 8.2 months starting 24.2 months after the insult. Each treatment session averaged 45 min in duration.

In 17 out of 20 patients a significant and stable increase of the visual field size (average 11.3 degrees +/- 8.1) was observed as well as improvement of the detection rate in the defective visual field (average 18.6% +/- 13.5). A two-factor cluster analysis demonstrated that binocular treatment was in general more effective in augmenting the visual detection rate than monocular. Four out of five patients with a visual field increase larger than 10 degrees suffered from hemorrhage, whereas all seven patients with an increase of 5 degrees or less suffered from infarction. Most patients reported that visual field restoration correlated with improvement of visual-related activities of daily living.

Rehabilitation treatment with the Lubeck Reaction Perimeter is a new and efficient method to restore part of the visual field in hemianopia. Since successful transfer of treatment effects to the occluded eye is achieved under monocular treatment conditions, it is hypothesized that the damaged visual cortex itself is the structure in which recovery takes place.