title: Evidence for a neuropathic aetiology in the small pupil of diabetes mellitus.
abstract: Infrared television pupillometry was performed on 34 insulin-treated diabetic patients and 55 healthy subjects. Sixteen of the diabetic patients had pupils that failed to dilate normally in darkness. The occurrence of a small pupil was associated with cardiac vagal dysfunction and somatic sensory loss. The small pupil was found to be supersensitive to the mydriatic effect of topical 2% phenylephrine but normally sensitive to 0.5% hydroxyamphetamine eyedrops. It is concluded that the failure of the pupil to dilate in darkness in some diabetic patients is due to neuropathy of the sympathetic innervation.
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D003624:Darkness; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D006801:Humans; D007498:Iris / Q000294:innervation*; D008875:Middle Aged; D010656:Phenylephrine / Q000494:pharmacology; D011680:Pupil / Q000187:drug effects / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000503:physiopathology; D010136:p-Hydroxyamphetamine / Q000494:pharmacology
chemical_list: D010656:Phenylephrine; D010136:p-Hydroxyamphetamine