Pupillary and visual field evaluation in patients with melanocytoma of the optic disc
R. H. Osher, J. A. Shields and P. R. Layman
Twenty patients with melanocytoma of the optic disc underwent Goldmann
perimetry and pupillary evaluation. Two patients (10%) had normal visual
fields. Three (15%) had minimal blind spot enlargement. Fifteen patients
(75%) had a greatly enlarged blind spot, of which ten had concomitant nerve
fiber bundle field defects. These consisted of a nasal step in two cases
(10%), relative nerve fiber bundle defects in four cases (20%), and an
absolute arcuate defect in four cases (20%). The blind spot enlargement
relates to the pigmented tumor extended beyond the disc boundary, thereby
shading the peripapillary retina. The nerve fiber bundle defects result
from injury to the visual axons passing through the nerve head, although
the mechanism is uncertain. A Marcus Gunn pupillary sign produced by the
melanocytoma was found in six patients (30%), all of whom had a substantial
relative or absolute nerve fiber bundle defect.
