Isolated congenital hemianopia caused by prenatal injury to the optic radiation.

Isolated congenital hemianopias are typically caused by developmental abnormalities of the occipital lobe cortex. We describe two patients with an incidental partial hemianopia associated with unilateral periventricular leukomalacia that was acquired prenatally. Magnetic resonance imaging scans suggest a late second or early third trimester unilateral cerebral ischemic event.