Central Retinal Vein Occlusion and Branch Retinal Vein Occlusion

Major risk factors include

Other risk factors include

Occlusion may also be idiopathic. The condition is uncommon among young people. Occlusion may affect a branch of the retinal vein or the central retinal vein.

Neovascularization (abnormal new vessel formation) of the retina or iris (rubeosis iridis) occurs in about 16% of patients with central retinal vein occlusion and can result in secondary (neovascular) glaucoma, which can occur weeks to months after occlusion. Vitreous hemorrhage may result from retinal neovascularization.

Painless vision loss is usually sudden but it can also occur gradually over a period of days to weeks. Funduscopy reveals hemorrhages throughout the retina, engorged (dilated) and tortuous retinal veins, and, usually, significant retinal edema. These changes are typically diffuse if obstruction involves the central retinal vein and are limited to one quadrant if obstruction involves only a branch of the central retinal vein.

The diagnosis is suspected in patients with painless vision loss, particularly those with risk factors. Funduscopy, color photography, and fluorescein angiography confirm the diagnosis. Optical coherence tomography is used to determine the degree of macular edema and its response to treatment. Patients with a central retinal vein occlusion are evaluated for hypertension Hypertension Hypertension is sustained elevation of resting systolic blood pressure (≥ 130 mm Hg), diastolic blood pressure (≥ 80 mm Hg), or both. Hypertension with no known cause (primary; formerly, essential... read more and glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible... read more and tested for diabetes Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more . Young patients are tested for increased blood viscosity (with a complete blood count and clotting factors as deemed necessary).

Most patients have some visual deficit. In mild cases, there can be spontaneous improvement to near-normal vision over a variable period of time. Visual acuity at presentation is a good indicator of final vision. If visual acuity is at least 20/40, visual acuity will likely remain good, occasionally near normal. If visual acuity is worse than 20/200, it will remain at that level or worsen in 80% of patients. Central retinal vein occlusions rarely recur.

Treatment for branch retinal vein occlusion in patients with macular edema that involves the fovea is usually intraocular injection of an anti-VEGF drug (eg, ranibizumab, aflibercept, or bevacizumab) or intraocular injection of triamcinolone or a slow-release dexamethasone implant. These treatments can also be used to treat central retinal vein occlusion in patients with macular edema. With these treatments, vision improves significantly in 30 to 40% of patients.

Focal laser photocoagulation can be used for branch retinal vein occlusion with macular edema but is less effective than intraocular injection of an anti-VEGF drug or a dexamethasone implant. Focal laser photocoagulation is typically not effective for the treatment of macular edema due to a central retinal vein occlusion.

If retinal or anterior segment neovascularization develops secondary to central or branch retinal vein occlusion, panretinal laser photocoagulation should be done promptly to decrease vitreous hemorrhage and prevent neovascular glaucoma.