The usefulness of a new method of testing for a relative afferent pupillary defect in patients with ocular hypertension and glaucoma.

PURPOSE To evaluate the validity of different methods of relative afferent pupillary defect (RAPD) detection and assess the usefulness of detecting an RAPD in glaucoma patients. METHODS For this prospective observational study, we enrolled 70 of 153 consecutive glaucoma patients coming for examination. Exclusion criteria were cloudy corneas, recent surgery, fixed pupils, and other diseases producing RAPDs. Inclusion criteria were any type of glaucoma and absence of any exclusion criterion. Patients were examined for an RAPD by the swinging flashlight method (SFM), a magnifier-assisted swinging flashlight method (MAM), and automated pupillography. The SFM and MAM results were compared with those obtained by pupillography. Receiver operating characteristic curves and the area under the curve (AUC) were determined. Correlations of other optic disc and visual field indices of glaucoma damage with RAPD were determined. RESULTS We confirmed RAPDs in 39 (56%) of the subjects by pupillography, finding a sensitivity of 41% and 84% and a specificity of 90% and 76% for SFM and MAM, respectively. The AUC was 0.86 for MAM and 0.61 for SFM. The correlations (r) between RAPD with intereye differences in the optic disc and visual field indices of glaucoma damage were moderate. CONCLUSIONS A modified swinging flashlight test with magnification increases the sensitivity of the test in detecting an RAPD. Because the detection of an RAPD may precede apparent optic disc and visual field damage, looking for an RAPD may be an important part of the assessment of patients with glaucoma.