Background Previous authors have suggested that an afferent pupillary defect (APD) may serve as an effective screening tool for some specific eye diseases, especially glaucomatous optic neuropathy, since the disease usually presents asymmetrically. Its success as a screening tool for glaucoma has never been previously prospectively evaluated in a large population.

Methods In this study, the authors carry out assessments for the presence of APD as it relates to the diagnosis of glaucoma in an existing population-based eye study in southern India. The authors calculate the sensitivity and specificity for APD, both at the level of a village/household screening and in a more comprehensive/hospital setting, as it pertains to its ability to predict glaucomatous optic neuropathy.

Results and discussion The authors find that APD assessed via the swinging flashlight test is a poor screening tool for glaucoma in this setting.