title: Pupillary dilation lag is intermittently present in patients with a stable oculosympathetic defect (Horner syndrome).
abstract: OBJECTIVE
  To examine the repeatability of detecting pupillary dilation lag in patients with Horner syndrome.
  
  
  METHODS
  Retrospective interventional study.
  
  
  METHODS
  
  
  
  METHODS
  Single referral institution.
  
  
  METHODS
  Fifteen patients with unilateral Horner syndrome and 16 subjects with physiologic anisocoria. Intervention procedure: Each subject underwent four pupillometric recordings in darkness. The asymmetry of pupillodilation between the two eyes was calculated as the change in anisocoria between five seconds and 15 seconds in darkness. Pupillary dilation lag was considered present if the asymmetry measured > or =0.4 mm.
  
  
  METHODS
  Asymmetry of pupillodilation over four determinations.
  
  
  RESULTS
  All subjects demonstrated fluctuations in the calculated asymmetry of pupillodilation. Eight patients (53%) with Horner syndrome demonstrated dilation lag on the first determination; 13 patients (87%) eventually demonstrated it during four determinations.
  
  
  CONCLUSIONS
  Pupillary dilation lag is intermittently present in most patients with Horner syndrome. Repeated observations improve the detection rate of dilation lag, a confirmatory sign of an oculosympathetic deficit. Its absence does not rule out Horner syndrome.
authors: Department of Neuro-ophthalmology, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland.
authors: Sylvain V
authors: SV
authors: Crippa
authors: François-Xavier
authors: FX
authors: Borruat
authors: Aki
authors: A
authors: Kawasaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006732:Horner Syndrome / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology; D011681:Pupil Disorders / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies