The Localizing Value of the Relative Afferent Pupillary Defect in Patients with Efferent Ocular Disease

Although the relative afferent pupillary defect (RAPD) is a well-known objective, rapid assessment of the afferent visual system, the localizing significance of the RAPD is particularly critical in some cases of efferent ocular disease. We present a case where the chief complaint was diplopia and the examination of the efferent pathway disclosed a strabismus. Neuroimaging studies of the brain were normal but orbital imaging confirmed a structural lesion. The importance of detection of an RAPD should be emphasized as part of the preoperative orthoptic measurements prior to strabismus surgery.