Mechanism of Bowtie atrophy

Mechanism of "bow-tie" atrophy due to an optic tract lesion. Top: Following a chronic lesion ("X") in the left optic tract, three groups of retinal ganglion cell fibers atrophy: A: those from the nasal half of the macula in the right eye; B, those from the nasal retina in the right eye; and C, those from the temporal retina of the left eye. A and B result in a bow-tie or band pattern of optic atrophy (white areas) in the right disc, and C result in temporal atrophy of the left disc (white area). Bottom: This pattern of optic atrophy is similar to that seen in homonymous hemianopic atrophy due to a congenital lesion of the geniculocalcarine pathway.