Protein C and Protein S as a Risk Factor for Retinal Vein Occlusion

ABSTRACT

PURPOSE: The authors evaluated the possibility of protein C and protein S as risk factors for retinal vein occlusion (RVO). METHODS: We evaluated the medical histories and performed laboratory tests, including protein C and protein S, in patients who were diagnosed with RVO by fundus examination and fluorescein angiography. The same data were obtained from a healthy control group. We analyzed mean activity and the ratio of patients with decreased levels of protein C or protein S. RESULTS: Forty-seven patients with RVO in this study consisted of 14 with central retinal vein occlusion (CRVO) and 33 with branch retinal vein occlusion (BRVO). Sixteen normal subjects were also enrolled in this study as controls. There are no cases that presented decreased protein C activity. However, there was a statistically significant difference in the number of cases with protein S deficiency between the patients and the control group (p<0.05). CONCLUSIONS: Deficiency of anticoagulant proteins, especially protein S, may be a risk factor of retinal vein occlusion. Examination of the coagulation system may be useful in the systemic evaluation of RVO patients.