Dilute pilocarpine test for diagnosis of Adie's tonic pupil.

We have compared the diagnostic ability of different concentrations of 0.125% and 0.0625% dilute pilocarpine for detecting denervation supersensitivity in unilateral Adie's tonic pupil. This retrospective, observational, case-control study involved 117 subjects, consisting of 56 patients with unilateral Adie's tonic pupil and 61 controls with other causes of unilateral dilated pupils. Subjects underwent the dilute pilocarpine test with one of the two concentrations, 0.125% or 0.0625%. Pupillary light reflex was recorded with a dynamic pupillometer at baseline and at 30-40 min after instilling one of the two concentrations of dilute pilocarpine. Diagnostic accuracy of two different concentrations of the dilute pilocarpine test, 0.125% group versus 0.0625% group, were compared by area under the receiver operating characteristic curve (AUC). Diagnostic ability of the dilute pilocarpine test for detecting denervation supersensitivity in unilateral Adie's tonic pupil was significantly better in the 0.0625% group than in the 0.125% group (AUC = 0.954 vs. 0.840, respectively, P = 0.047). In the 0.0625% group, the change in maximal pupil diameter of ≥ 0.5 mm after topical pilocarpine instillation showed 100% sensitivity and 82.8% specificity for detecting Adie's tonic pupil. This study confirmed that pupillary constriction with 0.0625% pilocarpine is better than 0.125% pilocarpine for detecting denervation supersensitivity in Adie's tonic pupil. Digital pupillometry is a reliable method for assessing denervation supersensitivity in Adie's tonic pupil.