Role of Hyperhomocystinemia in Retinal Vascular Occlusive Disease

Abstract

Elevated plasma homocysteine (Hcy) level is considered a risk factor for vascular diseases. In recent years, many scientific reports have suggested that hyperhomocystinemia may be associated with an increased risk of retinal vascular occlusive disease (RVOD). The prevalence of elevation of homocysteine in patients with a recent retinal vascular occlusion was compared to a health control group in this study. Forty-nine consecutive patients (22 M; 27 F) (age 26-85 years, mean 69) with diagnosis of retinal vascular occlusion were compared with 71 healthy controls. These patients underwent laboratory evaluation for plasma fasting total homocysteine, activated protein C resistance, protein C, protein S, antithrombin III, and antiphospholipid and anticardiolipin antibodies. The G20210 prothrombin gene mutation (FII G20210A) and Factor V Leiden mutation (FVL) were evaluated. None of these enrolled subjects had other prothrombic risk factors. The health control group consisted of healthy subjects from the general population, with no history or clinical evidence of retinal vascular disease, recruited during the same 2-year period. High fasting homocystinemia (higher than 15 mumol/L) was detected in 24/49 subjects (48.9%) (P < .0005). There was a high prevalence of hyperhomocystinemia: these data suggest an association between RVOD and high fasting homocystinemia. Elevated homocysteine may be an independent risk factor, and its assessment may be important in the investigation, management, and follow-up of patients with RVOD. Further controlled studies are necessary to clarify the exact role of hyperhomocystinemia in RVOD and to evaluate the appropriate therapeutic approach.

Homocysteine and Internal Carotid Artery Occlusion in Ischemic Stroke

“…Vascular obstruction associated with increased tHcy has been reported most often in association with retinal vascular occlusive diseases 24,25) . A prior study of carotid atherosclerosis reported that tHcy levels were highest in patients with ICA occlusion; this result was borderline significant 26) ; however, that study included young patients of less than 55 years old, and the proportions of stroke were diverse in the groups ranging from 5.7% (control) to 75.0% (ICA occlusion).…”

Retinal vein occlusion: evaluation of “classic” and “emerging” risk factors and treatment

“…Elevated plasma homocysteine level is considered a risk factor for vascular diseases. In recent years, many scientific reports have suggested that hyperhomocystinemia may be associated with an increased risk of RVO [9][10][11][16][17][18]. High levels of this amino-acid caused by several conditions such as diabetes, renal failure, dietary deficiency of folate or vitamins B12 and B6, drugs, elderly or genetic mutations may cause an endothelial dysfunction with a prothrombotic haemostatic changes.…”

“…Several studies have shown that systemic risk factors as arterial hypertension, diabetes mellitus and hyperlipidemia are associated with RVO [5,6]. Some recent publications have reported the correlations among RVO and defects on haemostasis [7,8] or among RVO and thrombophilia [9][10][11][12], but the role these play in the development of retinal diseases is still not totally clear.…”

Selective thrombophilia screening of patients with nonarteritic anterior ischemic optic neuropathy

“…Attention has shifted in recent years to the characterization and evaluation of novel risk factors of arterial thrombosis, including lipoprotein metabolism and the coagulation and fibrinolytic systems [6,12,19,20,32].…”