Retinal vein occlusion.

In this review of the retinal vein occlusion (RVO), I have summarized recent advances on several controversial and clinically important topics: classification of RVO into six distinct clinical entities; pathogeneses and demographic characteristics of various types of RVO; differentiation of non-ischemic from ischemic central retinal vein occlusion (CRVO); differentiation of hemi-CRVO (HCRVO) from major branch RVO (BRVO); and the course, complications and management of various types of RVO.