Even today, the understanding of the disease and its treatment is still evolving. From the perspective of the emergency physician, it is useful to conceptualize RVO as being comprised of 2 distinct entities. The 2 entities have different etiologies, presentations, and ultimate outcomes. When a patient is referred for further evaluation and treatment by an ophthalmologist, much of their initial work involves discerning the 2 basic types. It is possible to further separate RVO into a more elaborate framework based on the vein affected, but this belongs in the realm of an ophthalmologist more than it does the emergency physician.
Most researchers believe that the pathogenesis is multifactorial.
Ischemic RVO is associated with significant complications. Nonischemic RVO has a good prognosis and outcome unless the macula is involved. Mortality and morbidity may occur secondary to an underlying pathology. More than one half of cases occur in people older than 65 years. Retinal hemorrhages may be found incidentally on funduscopic examination without visual complaint, or patients may complain of increasing blurry vision, which usually is worse in the morning upon waking and improves throughout the day.