A Relative Afferent Pupillary Defect Without Any Visual Sensory Deficit

A 54-YEAR-OLD woman was an unrestrained driver in a high-speed, motor vehicle accident. She was stabilized but remained in a coma requiring intubation for 8 days. Neuroimaging performed on admission to the hospital showed a subarachnoid hemorrhage, a small subdural hematoma, and a basal skull fracture. As the patient recovered from her coma, she was noted to have marked left facial weakness and diplopia. The patient was evaluated 6 weeks after the accident and had a visual acuity of 20/20 OU and no color vision deficit by color plate testing. Full visual fields were measured by both kinetic perimetry with a Goldmann perimeter and static perimetry using a 24-2 strategy on a Humphrey automated perimeter. Despite the lack of any afferent visual deficit, there was a moderate right-sided relative afferent pupillary defect (Figure 1). Additionally, the patient had left fourth, left sixth, and left seventh nerve pareses. Magnetic resonance imaging revealed an infarction in the brachium of the left superior colliculus (Figure 2).