%0 Journal Article
%T Branch Retinal Vein Occlusion in Factor V Leiden Mutation - Branch Retinal Vein Occlusion in Factor V Leiden Mutation - Open Access Pub
%A Srinivasan Sanjay
%A Yan Tong Koh
%J OAP | Home | Journal of Ophthalmic Science | Open Access Pub
%D 2018
%X A previously healthy 25 year old Chinese male presented with left eye blurring of vision and was diagnosed to have left eye branch retinal vein occlusion. Initial blood investigations and thrombophilia screen were negative. The patient subsequently improved with observation and conservative management, with no further events over a 2 year follow up period. The blood investigations were repeated 2 years later as part of a health check-up and he was then tested to be heterozygous for the factor V leiden mutation. This was confirmed by sequencing of his genome that identified the mutation. The laboratory was contacted to provide details regarding the testing methods and was noted to have performed the two tests via different methods. While false negative rates in genetic testing are low, we believe that there is greater need to standardize testing methods as ascertaining genetic conditions play a great role in clinical diagnosis, treatment and prognosis. Clinicians should be aware of the limitations of these tests. When clinical suspicion is high, there may be a role for repeat tests with different methods or in different laboratories. DOI10.14302/issn.2470-0436.jos-14-528 Retinal vein occlusion (RVO) is a common ocular disease that results in acute visual loss. It is multifactorial in origin; while its exact mechanism and pathogenesis remains unclear, conditions like glaucoma, hypertension, arteriosclerosis and diabetes mellitus are commonly known associations with RVO especially in the older population. These conditions contribute to RVO either by affecting flow in the vasculature or causing abnormalities in vessel walls.1, 2, 3, 4, 5 As part of Virchow¡¯s triad, thrombophilic conditions also increase the risk of thrombosis. 6, 7 Examples of such conditions include resistance to activated protein C (APC) or factor V Leiden, hyperhomocysteinaemia, and deficiencies in the anticoagulation system (protein C, protein S, or antithrombin). In the normal coagulation cascade, protein C is a major component in anticoagulation mechanisms, as activated protein C (APC) inactivates highly procoagulant factors in the generation of thrombin such as activated factor V (factor Va) and factor VIII (factor VIIIa). Activated factor V is normally fully inactivated by an initial cleavage of a peptide bond on the carboxyl side of Arg506 followed by a second cleavage at Arg306. Subsequent cleavage also occurs at Arg679. [8] In the setting of factor V leiden mutation, there is a 1691 G to A mutation in the factor V gene, leading to an R506Q substitution in the factor V protein.
%U https://www.openaccesspub.org/jos/article/187