Hemianopia

The value of visual field defects in lesion localization is undisputed. Carefully plotted, they point unerringly to the site of the lesion. Nevertheless, most of us do not regularly extract the most information from our examination of visual field deficits, partly because of awkwardness, inefficiency, or inexpertness in the actual examination, and partly because our interpretation lacks the sureness required. This lesson describes the proper examination technique concisely and clearly. Although most practicing neurologists and neurosurgeons do not perform formal perimetry, careful confrontation testing should be sufficient in most instances to provide localization. Dr. Ellenberger's comments about the symptoms which occur in the hemianopias are interesting and clinically useful, as are the paragraphs describing the special diagnostic features of hemianopia. How many of us know, for example that the border of a field defect provides a clue as to whether the lesion causing it is stable or progressing?