Reversible congruous homonymous hemianopia as a symptom of shunt malfunction.

Congruous left homonymous hemianopia occurred as a symptom of ventriculoperitoneal shunt malfunction. The low attenuation along the ventricular catheter in the right occipital area that was seen on a computed tomography scan disappeared after revision of the shunt, and corresponded with improvement of this peculiar visual field symptom. In view of anatomic considerations and clinical course, this homonymous field defect might be caused by peritubular cerebrospinal fluid edema in the right occipital area. In evaluating the patients having shunts, precise neuroophthalmologic examination should be performed for possible visual field defects.