Description, symptoms, signs, prevalence, significance, differential diagnosis
See Central retinal vein occlusion – assessment.
Urgent Initial management relates to any underlying systemic disease or possible glaucoma. Treatment may help to reduce the risk of stroke (cerebrovascular accident) or a vascular occlusion in the other eye.
Blood tests Patients need a full blood work-up to treat any underlying systemic risk factors such as hypertension, diabetes, vasculitis, carotid stenosis or cardiovascular disease.
Oral medication Review antihypertensive and other medications, and consider daily aspirin. Consider discontinuing oral contraceptives if being present.
Ocular test Risk factors for glaucoma should be evaluated, and intraocular pressure reduced if necessary. Assess for neovascularization of the iris, angle, retina or optic nerve. Fluorescein angiography is usually indicated to assess retinal capillary non-perfusion, giving an indication of the risk of development of neovascular complications. Usually fluorescein angiography is indicated two to three months after a CRVO, once the hemorrhages have cleared.
Laser treatment In CRVO, the risk of neovascularization of the anterior eye is much greater than in BRVO. Particularly in ischemic CRVO, the iris is the nearest available, well-perfused uveal tissue and hence is at greatest risk of neovascularization. Hemi-central retinal vein occlusion and branch retinal vein occlusion (BRVO) are usually associated
with contiguous viable retinal circulation, and hence neovascularization of the disc or retina is more common in these conditions. Prompt panretinal photocoagulation (PRP) is indicated if neovascularization of the iris (>2 clock hours), anterior angle, disc or retina develops (Central Vein Occlusion Study or CVOS). The vision is unlikely to be improved by PRP; however, the treatment aims to eliminate retinal hypoxia and thereby avoid any further growth of the iris neovascularization and the prospect of neovascular glaucoma. A benefit of PRP in the prevention of onset of neovascularization after CRVO has not yet been shown, so prophylactic argon laser treatment is not usually conducted. Grid laser treatment of macula edema is not usually indicated, as vision is unlikely to improve.
Laser photocoagulation is sometimes applied with the aim of increasing retinal venous drainage by the creation of a collateral channel (anastomosis) through to the choroidal circulation. The laser treatment ruptures Bruch’s membrane with the intention of reducing the stimulus to neovascularization; however, this treatment is still experimental.
Advice and review As The visual prognosis relates to the presenting vision, and to the presence of capillary loss and retinal ischemia. Unfortunately, no reliable treatment is yet available to improve the vision fotlowing CRVO; however, there should be follow-up of any underlying medical conditions. Neovascularization-related complications are a significant risk, particularly in ischemic CRVO. Regular review is recommended to assess the possible onset of neovascularization of the iris, with gonioscopic evaluation of the anterior angles at 1 – to 2-monthly intervals for the first 12 months (see Neovascular glaucoma).
Sub-acute longstanding central retinal vein occlusion (CRVO): lipid exudate, collateral vessels on disc and atrophy of retinal pigment epithelium at the macula secondary to CRVO.
Resolved central retinal vein occlusion (CRVO) with collateral vessels on optic disc. The retina appears normal: visual function, although improved, remained impaired.