Eye patching and the rehabilitation of visual neglect

A study was performed to evaluate the effectiveness of right eye patching as a rehabilitation technique for left-sided visual neglect. The rationale behind eye patching is based on the theory that patching the patient's ipsilesional eye will reduce the input to the contralesional superior colliculus, thus increasing the effectiveness of the ipsilesional colliculus in making eye movements into the contralesional visual field (cf. Butter & Kirsch, 1992; Posner & Rafal, 1987). Right eye patching should therefore ameliorate left-sided visual neglect, whereas left eye patching should exacerbate it. Nine brain-injured patients with right hemisphere lesions and symptoms of unilateral neglect were tested on five different tests of visual neglect, under normal viewing conditions and when either their right eye or left eye was patched. The results showed that right eye patching did not produce a consistent reduction in the severity of neglect. Three patients showed a decrease in neglect following right eye patching on one or more of the tests used. Four patients showed the opposite trend, and their neglect increased following right eye patching. The level of neglect of two patients was unaffected by patching either eye. In the cases where right eye patching altered the severity of neglect (with either an increase or a decrease in neglect) it was found that left eye patching had a similar effect. These results show that eye patching is unlikely to be of general usefulness in the rehabilitation of neglect.