title: Type II protein C deficiency in a 16-year-old girl with central retinal vein occlusion.
abstract: OBJECTIVE
  To report a case of central retinal vein occlusion in the setting of type II protein C deficiency, and to describe the appropriate tests for detecting this clotting abnormality.
  
  
  METHODS
  Observational case report.
  
  
  METHODS
  Retrospective review of clinical examination and laboratory findings.
  
  
  RESULTS
  A 16-year-old girl was evaluated for progressive monocular vision loss occurring over a period of one month. Dilated fundus examination and fluorescein angiography revealed the presence of a central retinal vein occlusion. Hypercoagulable work-up demonstrated normal protein C antigen levels, but a marked reduction in protein C function, confirming a type II protein C deficiency.
  
  
  CONCLUSIONS
  Central retinal vein occlusion may be associated with type II protein C deficiency. Testing for protein C antigen levels and function is necessary for detection of both type I and type II protein C deficiency.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, Wisconsin 53792, USA.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Vrabec
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Levin
mesh_terms: D000293:Adolescent; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D020151:Protein C Deficiency / Q000175:diagnosis* / Q000235:genetics; D012170:Retinal Vein Occlusion / Q000175:diagnosis*; D012189:Retrospective Studies; D014786:Vision Disorders / Q000175:diagnosis; D014792:Visual Acuity