Macular sparing investigated by means of Haidinger brushes.

Haidinger brushes, an entoptic phenomenon perceived only through the most central macular retina, have been used in addition to kinetic and static perimetry with the Tubingen perimeter for determining macular sparing and splitting in hemianopic patients. Seven patients were examined: 2 with a bitemporal hemianopia resulting from traumatic damage to the optic chiasma, and 5 with a homonymous hemianopia resulting from extensive lesions of the optic radiations and/or the occipital cortex (including 2 cases of hemidecortication). On perimetric examination some exceptions could be observed in the correspondence of macular splitting and sparing respectively with pre- and postgeniculate lesions, but this was not the case when Haidinger brushes were used. Half of the figure was then perceived by the patients with lesions of the chiasma and the entire figure by all the patients with geniculostriate lesions. We consider that results obtained by this simple method are more reliable than those obtained by perimetry and that Haidinger brushes should be used for macular field examination in neuro-ophthalmic practice.