Evolution of the retinal vein occlusion. Platelet glycoprotein GPIIIa and other risk factors (Spanish text)

Objective. Although the pathogenesis of retinal vein occlusion (RVO) is multifactorial, recent studies suggest that thrombotic and fibrinolytic systems may be main contributing factors. As individual differences in the thrombogenicity of platelets, based in structural differences in the glycoprotein platelet receptor, have been shown to be associated with thromboembolic and ischemic diseases, we wondered if the platelet glycoprotein IIIa polymorphism PlA2 influence in the incidence, complications and visual prognosis of patients with different forms of presentation of RVO.; Design and methods. We complete a prospective study of cases and controls and one year follow up in 57 consecutive cases of RVO (corresponding 57 eyes from 52 patients). Clinical (ophthalmic and systemic) and analytical variables, including the polymorphism PlA2, were obtained at diagnosis and follow up. Similar studies were performed in a control group matched with cases for age and sex.; In a logistic regression model we analyzed most known risk factors and variables, including PlA2 polymorphism, and correlated with final VA and ocular complications. Control of systemic associated disease and photocoagulation was applied when necessary.; Results. The presence of the PlA2 allele has been shown to be significantly elevated in patients with RVO respect control group in allele (p 0.007) and genotypic frequency (p 0.014) acting as a risk factor like arterial hypertension, hyperhomicisteynemia and cardiovascular associated disease. We found a close relationship between the presence of the PlA2 allele and the incidence of perfused or non ischemic macular edema (88.9% vs. 48.71%, OR = 8.42 p = 0.004). This result was consistent in all groups of age and topography of occlusion (branch or central).; Conclusions. Being the prognosis of RVO is unpredictable because complications within the first months of evolution, the characterization for the PlA₂ polymorphism allows the early identification of patients with a significative risk for persistent perfused or non ischemic macular edema at the time of the RVO occurrence. This observation could eventually provide important indications regarding prognosis and therapeutic strategies.