SNOMED CT — central retinal vein occlusion disorder
Laboratory Tests
Routine labs — all CRVO patients
Cardiovascular risk assessment
Fasting glucose and HbA1c
Undiagnosed diabetes in substantial proportion
HbA1c reflects 3-month glycemic control
Lipid panel
LDL, HDL, total cholesterol, triglycerides
Dyslipidemia as modifiable risk factor
Complete blood count with differential
Polycythemia — hyperviscosity from elevated red cell mass
Thrombocytosis — thrombotic risk
Leukemia — infiltrative cause of venous occlusion
BMP or CMP — renal function and electrolytes
Renal disease associated with cardiovascular risk
Medication dosing considerations
Blood pressure measurement — systemic, both arms
Selective labs — younger patients and bilateral CRVO
Thrombophilia workup — age younger than 50, bilateral CRVO, no traditional risk factors
Homocysteine level
Most consistently associated thrombophilia in CRVO
Hyperhomocysteinemia treatable with folate, B6, B12
Antiphospholipid antibodies
Anticardiolipin IgG and IgM
Anti-beta-2 glycoprotein I
Lupus anticoagulant
Protein C activity
Protein S activity
Antithrombin III activity
Factor V Leiden — most common inherited thrombophilia
Prothrombin G20210A mutation
Hyperviscosity screen — bilateral RVO or young patient
Serum protein electrophoresis
Rules out multiple myeloma and Waldenstrom macroglobulinemia
Serum viscosity if SPEP abnormal
Additional targeted labs
Inflammatory and autoimmune markers
ESR and CRP — vasculitis suspected
ANA — SLE screen
SLE associated with 3.5 times higher CRVO incidence
ANCA if vasculitis suspected
Cardiac markers
ECG — screen for AF, cardiac ischemia
AF prevalence 10–18% in RVO patients
Note: Meta-analysis found prevalences of inherited thrombophilias in RVO similar to healthy subjects — routine thrombophilia screening not supported in typical older patients with traditional risk factors
Diagnostic Tests
Scoring Systems
Ischemic vs non-ischemic classification — critical prognostic distinction
Non-ischemic CRVO features
Approximately 80% of presentations
VA usually >= 20/200
Absent or mild RAPD
Mild-moderate scattered hemorrhages
Few cotton-wool spots
FFA non-perfusion < 10 disc areas
Neovascular glaucoma risk rare
Final VA >= 20/100 in 83%
Ischemic CRVO features
Approximately 20% of presentations
VA usually < 20/200
RAPD present
Large confluent hemorrhages
Multiple cotton-wool spots
FFA non-perfusion >= 10 disc areas
Neovascular glaucoma risk approximately 23% within 15 months
Final VA >= 20/100 in only 12%
Conversion risk — 25–34% of non-ischemic convert to ischemic within 3 years
MRI
MRI ocular and orbital indications
Limited acute utility for CRVO diagnosis
Not first-line imaging modality
Availability and time constraints
Problem-solving indications
Orbital or optic nerve pathology suspected
Infiltrative process or compressive lesion
Exclude CNS lesion when visual loss with neurologic symptoms
MRI brain — consider when
Young patient with bilateral visual symptoms
Associated neurologic deficits suggesting stroke
Multiple sclerosis or demyelination on differential
Contraindications
Non-compatible ocular or systemic implants
Hemodynamically unstable patient
CT
CT head and orbit — selected indications
Rule out intracranial process — papilledema on differential
Bilateral disc edema requires CT or MRI before LP
ICP elevation and mass lesion exclusion
CT angiography — carotid and cerebrovascular evaluation
Carotid occlusive disease as contributor to ocular ischemic syndrome
Stroke workup in high-risk patients
CT chest — paraneoplastic or systemic malignancy workup
If SPEP abnormal or lymphoma suspected
Contrast considerations
Renal function assessment before contrast
Allergy history
Ultrasound
Ocular ultrasound — B-scan
Vitreous hemorrhage obscuring fundus view
B-scan to assess retinal detachment beneath hemorrhage
Rules out rhegmatogenous detachment
Retinal detachment screen when fundus not visible
High reflectivity membrane with attachment at disc
Choroidal detachment assessment
Carotid Doppler ultrasound
Carotid occlusive disease evaluation
Stenosis contributing to reduced ocular perfusion
Bilateral comparison
Consider in patients with carotid bruit or multiple cardiovascular risk factors
SNOMED CT — central retinal vein occlusion disorder
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