Related Experiment Video
Updated: Jul 17, 2026

Optimization of the Retinal Vein Occlusion Mouse Model to Limit Variability
Published on: August 6, 2021
Type II protein C deficiency in a 16-year-old girl with central retinal vein occlusion
Joshua P Vrabec1, Leonard A Levin
1Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, Wisconsin 53792, USA.
Purpose:
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.
Design:
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.
Related Concept Videos
Diabetic Retinopathy
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Venous Thrombosis I: Introduction
Type I Diabetes II: Pathophysiology
Venous Thrombosis III: Interprofessional Care
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.