Preconceived ideas, paradoxes, and new concepts in retinal vein occlusion

Retinal vein occlusion is the second cause of vascular retinopathy after diabetic retinopathy and often leads to poor visual outcome. In a simplified form, the authors attempt to rectify a number of preconceived ideas about retinal vein occlusion and introduce new concepts in order to assist in the understanding of their mechanisms. Various paradoxes are explained, such as the presence of arterial risk factors in this venous disorder, the atypical combination of retinal ischemia and the absence of vascular non-perfusion on fluorescein angiography, the fact that macular edema is larger in the ischemic form than in the well-perfused form, the aggravating role of contraceptive hormonal therapy, the protective role of substitutive hormonal therapy, etc. The current controversies are underlined: the seasonal onset of the disease, the role of vasodilator treatment, the place of etiologic screening, and the significance of pre-papillary loops. Lastly, the authors summarize important basics about treatment modalities, even if there is not yet consensus on the treatment of retinal vein occlusion. (C) 2011 Elsevier Masson SAS. All rights reserved.