Retinal vein occlusion.

Retinal vein occlusion is one of the most common causes of retinal vascular abnormality and a frequent cause of vision loss. It is an obstruction of the retinal venous system by thrombus formation and may involve the central, hemicentral or branch retinal vein. It typically occurs in middle-aged and elderly patients, and its increased occurrence is therefore associated with the increased aging of the world’s population and increased longevity. Until recently, the treatment options have been extremely limited, but this situation is changing rapidly with the increased availability of intravitreal administration of steroids and anti-VEGF (vascular endothelial growth factor) agents. Retinal vascular disease progresses by two major disease mechanisms: (1) alteration to the inner blood-retinal barrier with resulting increased vascular permeability and edema, and (2) vessel closure with resulting ischemia leading to the development of abnormal neovascularization. These two major disease processes are closely associated with an abnormal inflammatory repair process. Steroids are particularly potent drugs to reduce inflammation and vascular permeability. Anti-VEGF agents correct increased vascular permeability and ischemia with its stimulus for the development of neovascularization. Ophthalmologists now have new options to manage and control retinal vascular occlusions. The available information mainly obtained from clinical trials applies to specific groups of patients and to the inclusion criteria of these trials. It is a challenge for ophthalmologists to interpret these clinical trials and to use these new therapeutic options according to the needs of each specific eye and patient. The development of guidelines for the treatment of retinal vein occlusion based on consensus achieved by well-established experts is, therefore, clearly relevant and of immediate interest to our readers. EURETINA and Ophthalmologica have established a partnership for the advancement of our knowledge about the management of retinal diseases, with the interest and vision preservation of each patient as the major common goals. It is, therefore, with pleasure that we have dedicated this issue to consensus guidelines for the management of retinal vein occlusion. José Cunha-Vaz, Coimbra Published online: May 17, 2011 Ophthalmologica