Retinal vein occlusions in patients treated with anticoagulant and/or platelet aggregation inhibitors. Five case studies

Introduction: Retinal vein occlusions (RVOs) are a common cause of severe or total loss of vision. Although the disease entity has long been known, its management is still controversial. We report five patients (six eyes) who experienced RVO even though they were taking anticoagulants or antiplatelet agents. Case reports: Two patients developed a central retinal vein occlusion (two eyes), two patients a branch retinal vein occlusion (two eyes), and one patient a bilateral central retinal vein occlusion (two eyes). Three patients were treated with anticoagulants, two for hemostatic pathologies and one for cardiopathy; two patients were treated with antiplatelet agents, one for auricular fibrillation and one for a cardiac graft. Retinal photocoagulation was performed in all cases to treat retinal ischemia. Neovascular glaucoma occurred in a single eye. Discussion: Treatments for thromboembolic disorders are more and more commonly used for various indications. Nevertheless, many patients develop RVO while taking such treatments, even though the International Normalized Ratio (INR) shows good patient compliance. Many case reports and small case series illustrate the occurrence of RVO with such treatments. These examples seem to illustrate the lack of efficacy of anticoagulants and platelet aggregation inhibitors in preventing vascular complications in the retinal venous circulation. Conclusion: Anticoagulants and platelet aggregation inhibitors must only be used to treat systemic factors or thromboembolic disorders associated with RVO. These five case reports illustrate that anticoagulants and platelet aggregation inhibitors cannot guarantee that a severe RVO will not occur. A prospective study would be useful to analyze their advantages in RVO management.