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Emergency and Acute Medicine – Central Retinal Vein Occlusion
Overview
Central retinal vein occlusion (CRVO) is characterized by decreased visual acuity due to venous outflow obstruction of the retina. Vision loss is typically acute, unilateral, and painless. The condition results from impaired venous drainage leading to retinal hemorrhage, edema, and ischemia.
Pathophysiologic Types
Ischemic CRVO accounts for approximately 20–25% of cases and represents complete venous obstruction. Blocked venous return causes capillary backflow, extensive hemorrhage, macular edema, and retinal ischemia. Thrombosis is promoted by limited space at the lamina cribrosa, slow blood flow, vessel wall changes, adjacent arteriosclerotic arterial compression, and increased blood viscosity.
Nonischemic CRVO represents partial or incomplete occlusion and is generally milder with better visual prognosis.
Clinical Features
Patients present with acute, painless, unilateral loss of vision. In nonischemic CRVO, vision loss may be intermittent or incomplete. Visual acuity is often severely reduced, commonly worse than 20/200. An afferent pupillary defect may be present. Fundoscopic examination reveals dilated and tortuous retinal veins, widespread retinal hemorrhages involving all four quadrants in central involvement, optic disc edema, and cotton wool spots. Extensive hemorrhage produces the classic “blood and thunder” appearance.
Essential Assessment
Measure blood pressure. Perform visual acuity testing, visual field assessment, fundoscopy, and tonometry. Normal intraocular pressure ranges from 10–21 mm Hg.
Diagnostic Evaluation
Laboratory studies include CBC, PT/PTT, ESR, ANA, and serum protein electrophoresis to assess for systemic or hyperviscosity conditions. Fluorescein angiography, performed by ophthalmology, differentiates ischemic from nonischemic CRVO by identifying areas of capillary nonperfusion. Gonioscopy is used to evaluate for iris or angle neovascularization.
Differential Considerations
Amaurosis fugax or TIA, cavernous sinus thrombosis, diabetic or hypertensive retinopathy, hyperviscosity syndromes (sickle cell disease, polycythemia, leukemia, multiple myeloma), ocular ischemia syndrome, papilledema, retinal artery occlusion, retinal detachment, temporal arteritis, vitreous hemorrhage, severe anemia with thrombocytopenia, and functional vision loss.
Initial Management Principles
There are no prehospital eye-specific interventions. In the ED, address elevated intraocular pressure if present and manage underlying systemic conditions. The cornerstone of management is early recognition and urgent ophthalmologic referral.
Emergency Department Management
No therapy has proven definitive benefit in the ED setting. In consultation with ophthalmology, attempted therapies may include aspirin, anti-inflammatory agents, systemic corticosteroids, systemic anticoagulation, fibrinolytics (controversial), or laser chorioretinal anastomosis.
Definitive and Ophthalmologic Therapies
Ophthalmologists may use intravitreal corticosteroids such as triamcinolone or antivascular endothelial growth factor agents such as bevacizumab. Panretinal photocoagulation is often performed if neovascularization develops.
Disposition and Follow-Up
Admission depends on ophthalmologic assessment and need for intervention. Patients may be discharged if immediate ophthalmology follow-up is ensured. If ophthalmologic care is unavailable, initiate management of associated conditions and transfer to a facility with specialty services. Long-term follow-up is essential, particularly for ischemic CRVO, to detect neovascularization and secondary glaucoma. Patients require full medical evaluation for underlying vascular disease and comorbidity management.
Clinical Insights and Pitfalls
Elevated intraocular pressure from edema or neovascularization can worsen ischemia and lead to permanent vision loss if untreated. Bilateral CRVO or CRVO in young patients should prompt evaluation for hyperviscosity syndromes and systemic disease.
Overview
Central retinal vein occlusion (CRVO) is characterized by decreased visual acuity due to venous outflow obstruction of the retina. Vision loss is typically acute, unilateral, and painless. The condition results from impaired venous drainage leading to retinal hemorrhage, edema, and ischemia.
Pathophysiologic Types
Ischemic CRVO accounts for approximately 20–25% of cases and represents complete venous obstruction. Blocked venous return causes capillary backflow, extensive hemorrhage, macular edema, and retinal ischemia. Thrombosis is promoted by limited space at the lamina cribrosa, slow blood flow, vessel wall changes, adjacent arteriosclerotic arterial compression, and increased blood viscosity.
Nonischemic CRVO represents partial or incomplete occlusion and is generally milder with better visual prognosis.
Clinical Features
Patients present with acute, painless, unilateral loss of vision. In nonischemic CRVO, vision loss may be intermittent or incomplete. Visual acuity is often severely reduced, commonly worse than 20/200. An afferent pupillary defect may be present. Fundoscopic examination reveals dilated and tortuous retinal veins, widespread retinal hemorrhages involving all four quadrants in central involvement, optic disc edema, and cotton wool spots. Extensive hemorrhage produces the classic “blood and thunder” appearance.
Essential Assessment
Measure blood pressure. Perform visual acuity testing, visual field assessment, fundoscopy, and tonometry. Normal intraocular pressure ranges from 10–21 mm Hg.
Diagnostic Evaluation
Laboratory studies include CBC, PT/PTT, ESR, ANA, and serum protein electrophoresis to assess for systemic or hyperviscosity conditions. Fluorescein angiography, performed by ophthalmology, differentiates ischemic from nonischemic CRVO by identifying areas of capillary nonperfusion. Gonioscopy is used to evaluate for iris or angle neovascularization.
Differential Considerations
Amaurosis fugax or TIA, cavernous sinus thrombosis, diabetic or hypertensive retinopathy, hyperviscosity syndromes (sickle cell disease, polycythemia, leukemia, multiple myeloma), ocular ischemia syndrome, papilledema, retinal artery occlusion, retinal detachment, temporal arteritis, vitreous hemorrhage, severe anemia with thrombocytopenia, and functional vision loss.
Initial Management Principles
There are no prehospital eye-specific interventions. In the ED, address elevated intraocular pressure if present and manage underlying systemic conditions. The cornerstone of management is early recognition and urgent ophthalmologic referral.
Emergency Department Management
No therapy has proven definitive benefit in the ED setting. In consultation with ophthalmology, attempted therapies may include aspirin, anti-inflammatory agents, systemic corticosteroids, systemic anticoagulation, fibrinolytics (controversial), or laser chorioretinal anastomosis.
Definitive and Ophthalmologic Therapies
Ophthalmologists may use intravitreal corticosteroids such as triamcinolone or antivascular endothelial growth factor agents such as bevacizumab. Panretinal photocoagulation is often performed if neovascularization develops.
Disposition and Follow-Up
Admission depends on ophthalmologic assessment and need for intervention. Patients may be discharged if immediate ophthalmology follow-up is ensured. If ophthalmologic care is unavailable, initiate management of associated conditions and transfer to a facility with specialty services. Long-term follow-up is essential, particularly for ischemic CRVO, to detect neovascularization and secondary glaucoma. Patients require full medical evaluation for underlying vascular disease and comorbidity management.
Clinical Insights and Pitfalls
Elevated intraocular pressure from edema or neovascularization can worsen ischemia and lead to permanent vision loss if untreated. Bilateral CRVO or CRVO in young patients should prompt evaluation for hyperviscosity syndromes and systemic disease.
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