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Essentials of Diagnosis
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General Considerations
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Common causes of acute vision loss
Branch retinal vein occlusion is four times more common than central retinal vein occlusion
The major predisposing factors are the etiologic factors in arteriosclerosis (diabetes mellitus, systemic hypertension, hyperlipidemia) and glaucoma
Consider estrogen therapy (including oral contraceptives), inherited or acquired hypercoagulable states (thrombophilia) (see below), and antiphospholipid antibody syndromes
In bilateral retinal vein occlusions, consider hyperviscosity syndromes and paraproteinemias
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Check blood pressure
Ask about tobacco use
Ask women about estrogen therapy (including oral contraceptives)
Patients should also be asked about a history of glaucoma; intraocular pressure should be measured to assess for signs of open- or narrow-angle glaucoma
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Obtain screening studies for diabetes mellitus, hyperlipidemia, and hyperviscosity (especially in simultaneous bilateral disease), including serum protein electrophoresis
In younger patients, consider tests for
Antiphospholipid antibody syndrome (lupus anticoagulant)
Activated protein C resistance/Factor V Leiden
Protein C, protein S deficiency
Antithrombin deficiency
Hyperprothrombinemia (G20210A prothrombin gene mutation)
Increased factor VIII activity
Hyperhomocysteinemia
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Therapeutic Procedures
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Intravitreal injection of a vascular endothelial growth factor (VEGF) inhibitor (such as ranibizumab, bevacizumab, or aflibercept) is beneficial for macular edema due to either branch or central retinal vein occlusion
Intravitreal triamcinolone improves vision in chronic macular edema due to non-ischemic central retinal vein occlusion
Intravitreal implant containing dexamethasone
Beneficial in both central and branch retinal vein occlusion
However, carries the risk of glaucoma in 20–65% of patients
Causes cataract in all patients who have not already had cataract surgery
Retinal laser photocoagulation