Ocular Thrombosis 2010

CJ Glueck MD, Jewish Hospital Cholesterol Center

Ocular thrombosis includes branch and central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), amaurosis fugax (AF), and nonarter­itic ischemic optic neuropathy (NAION), all of which are closely related to coagulation abnormalities.(1-3) In the United States, retinal vein occlusions are the second most com­mon retinal vascular diseases, after diabetic retinopathy.

The most common coagulation disorder associated with CRVO and CRAO is hyperhomocysteinemia, usually associated with homozygosity for the MTHFR C677T  mutation, or compound heterozygosity for the MTHFR C677T and A1298C mutations. The elevated homocysteine can be reduced to normal with folic acid 5 mg, vitamin B6 100 mg, and vitamin B12 2000 mcg per day. Other thrombophilias associated with CRVO and CRAO include the Factor V Leiden mutation, the Prothrombin gene mutation, high Factor VIII, and high Factor XI.

In CRVO as well as in CRAO-AF-NAION, definition of coagulation eti­ologies is important because it allows for definition of appropriate acute antithrombotic therapy and subsequent thrombopro­phylaxis to prevent additional visual loss and also allows identification of those patients with thrombophilias so other thrombotic events can be avoided and appropriate family members assessed when clinically warranted. The associations of CRVO and CRAO-AF-NAION with thrombophilia has broad clinical implications because these coagulation disorders can cause preventable/revers­ible deep venous thrombosis and pulmonary emboli, ischemic stroke, myocardial infarction, osteonecro­sis, and sporadic and recurrent miscarriage.

References

1. Glueck CJ, Ping W, Hutchins R, Petersen MR, Golnik K. Ocular vascular thrombotic events: central retinal vein and central retinal artery occlusions. Clin Appl Thromb Hemost 2008;14(3):286-94.
2. Glueck CJ, Wang P, Bell H, Rangaraj V, Goldenberg N. Associations of thrombophilia, hypofibrinolysis, and retinal vein occlusion. Clin Appl Thromb Hemost 2005;11(4):375-89.
3. Glueck CJ, Bell H, Vadlamani L, Gupta A, Fontaine RN, Wang P, et al. Heritable thrombophilia and hypofibrinolysis. Possible causes of retinal vein occlusion. Arch Ophthalmol 1999;117(1):43-9.