- Clinical science
Retinal artery occlusion refers to occlusion of the central retinal artery and/or its branches, usually as a result of thromboembolic phenomena. Central retinal artery occlusion (CRAO) is characterized by sudden, painless loss of vision and a relative afferent pupillary defect. Ophthalmoscopy reveals a pale, edematous retina and a cherry-red spot in the foveal region. Branch retinal artery occlusion (BRAO) presents with specific patterns of visual field defects depending on which branch is involved. Treatment is usually ineffective because of irreversible ischemic damage to the retina. The prognosis is especially poor if the macula is involved. Retinal vein occlusion is more common than retinal artery occlusion and follows a less fulminant course. Branched retinal vein occlusion (BRVO), which is more common than central retinal vein occlusion (CRVO), is usually asymptomatic unless the macula is involved. CRVO may be either non-ischemic or ischemic. Fluorescein angiography is required in order to differentiate between ischemic and non-ischemic retinal vein occlusion. The prognosis of ischemic CRVO is less favorable since it is associated with neovascular glaucoma and retinal detachment. While BRVO and non-ischemic CRVO usually do not require any treatment, ischemic CRVO requires laser therapy.
- Age of onset: > 60 years
- Sex: ♂ > ♀
- Age of onset: > 80 years
- Sex: ♂ = ♀
Epidemiological data refers to the US, unless otherwise specified.
- Thrombosis of the retinal vessels (usually as a result of atherosclerosis)
- Rare causes: vasculitis (e.g., temporal arteritis), fibromuscular dysplasia
- Systemic diseases: , ,
- Hypercoagulable/prothrombotic states (e.g., polycythemia vera, sickle cell disease, oral contraceptive use)
- Ocular diseases:
|Symptoms|| || |
|Relative afferent pupillary defect|| || |
|General physical examination|
|Non-ischemic CRVO||Ischemic CRVO|
|Symptoms|| || || |
|Relative afferent pupillary defect|| || || |
- Definition: sudden, painless loss of vision that lasts for seconds to minutes and is followed by spontaneous recovery (mostly unilateral)
- Cause: retinal ischemia following transient occlusion of the central retinal artery by microemboli
- Although amaurosis fugax is self-limiting, it is a harbinger of more serious conditions. Therefore, perimetry and treatment of the underlying cause are essential:
Retinal vessel occlusion is primarily a clinical diagnosis (based on the patient's history and fundus examination). Additional investigations are usually performed to identify underlying risk factors, to differentiate between subtypes (e.g., in the case of CRVO).
- Evaluation for cardiovascular risk factors:
- Tests to rule out temporal arteritis:
- Fluorescein angiography: in order to differentiate ischemic from non-ischemic forms of retinal vein occlusion
- Eyeball massage
- Carbogen therapy: inhaling a mixture of 5% CO2 and 95% O2
- Decrease intraocular pressure; with drugs and/or surgical therapy (e.g., paracentesis of the anterior chamber)
- Vasodilators (e.g., calcium channel blockers, sublingual nitroglycerine)
- High-dose glucocorticoid therapy if temporal arteritis is suspected
Ischemic CRVO must be treated with:
- Laser therapy
- Panretinal photocoagulation
- If macular edema is present: grid photocoagulation
- Intravitreal injection of VEGF inhibitors and/or steroids
- Laser therapy
- BRVO and non-ischemic CRVO usually do not require treatment.
- Neovascularization of the iris ; () → neovascular glaucoma
- Neovascularization of the retina → vitreous hemorrhage → retinal detachment
We list the most important complications. The selection is not exhaustive.