Related Experiment Videos
Retinal vascular occlusion and deficiencies in the protein C pathway
1Department of Ophthalmology, Johannes Gutenberg-University Mainz, Germany. kg@bmp.de
Insights
The factor V R506Q mutation, a cause of resistance to activated protein C, is a significant risk factor for central retinal vein occlusion. Screening for this mutation is recommended in patients with this condition.
Area of Science:
- Ophthalmology
- Hematology
- Genetics
Background:
- Retinal vascular occlusion is a serious condition affecting vision.
- Understanding coagulation disorders and genetic predispositions is crucial for managing vascular occlusive diseases.
Purpose of the Study:
- To investigate abnormalities in the protein C pathway and other vascular occlusion risk factors in patients with retinal vascular occlusion.
- To determine the prevalence of the factor V R506Q mutation in patients with retinal vascular occlusion.
Main Methods:
- A study involving 76 patients with retinal vascular occlusion and 209 patients with deep vein thrombosis.
- Comprehensive coagulation disorder testing, including protein C, protein S, lupus anticoagulants, and resistance to activated protein C.
- Genetic analysis using polymerase chain reaction to detect the factor V R506Q mutation.
Main Results:
- The factor V R506Q mutation was found in 29% of central retinal vein occlusion patients and 19% of branch retinal vein occlusion patients.
- The mutation's prevalence was significantly higher in central retinal vein occlusion compared to the general white population.
- No deficiencies in protein C, protein S, or lupus anticoagulants were detected; the factor V R506Q mutation explained all cases of resistance to activated protein C.
Conclusions:
- The factor V R506Q mutation is a relevant risk factor for central retinal vein occlusion, with a prevalence similar to deep vein thrombosis.
- Genetic screening for the factor V R506Q mutation is recommended for all patients diagnosed with central retinal vein occlusion.
Purpose:
To report abnormalities in the protein C pathway and other vascular occlusion risk factors in patients with retinal vascular occlusion.
Methods:
In a study, we investigated 76 consecutive patients who had in-patient evaluation of venous or arterial retinal vascular occlusion. All patients underwent comprehensive tests for coagulation disorders including determinations of protein C, protein S, lupus anticoagulants, and resistance to activated protein C and were screened for vascular disease risk factors. Resistance to activated protein C was confirmed by a polymerase chain reaction method to detect the specific factor V R506Q mutation. For comparative purposes, we also screened 209 consecutive inpatients with deep vein thrombosis from the same geographic region for resistance to activated protein C as well as protein C and protein S deficiencies.
Results:
Ten (29%) of 35 patients with central retinal vein occlusion (CRVO) had factor V R506Q mutation. The factor V R506Q mutation was detected in four (19%) of 21 patients with branch retinal vein occlusion. The higher frequency in factor V R506Q mutation compared with the expected 9% mutation prevalence in a white population was highly significant for the central retinal vein occlusion group but not for the branch retinal vein occlusion group. In all patients with resistance to activated protein C, the factor V R506Q mutation was detected; 16 were heterozygous, one homozygous. No cases of lupus anticoagulants, protein C, or protein S deficiencies were detected. Forty (19%) of 209 patients with deep vein thrombosis were carriers of the factor V R506Q mutation.
Conclusions:
The prevalence of the factor V R506Q mutation is similar in patients with central retinal vein occlusion and patients with deep vein thrombosis and represents a relevant risk factor. Screening for this mutation is therefore recommended in all patients with central retinal vein occlusion.