BRANCH RETINAL VEIN OCCLUSION
Main risk factors:
- Raised IOP
What to consider in under 50?
- Myeloproliferative disease – polycythaemia, abnromal plasma protein (myeloma)
- Acquired hypercoagulable states – raised homocysteine levels, lupus anticoagulant, antiphospholipid antibodies
- Inhired hypercoagulable states – Factor V Leiden mutation, protein C or S deficiency, antithrombin deficiency, Factor VII deficiency
- Inflammation – Behcet syndrome, sarcoidosis, Wegener’s granulomatosis, Goodpasture syndrome
- Others – CRF, secondary HTN (Cushing syndrome), secondary hyperlipidaemia (hypothyroidism), orbital disease, dehydration.
- FBC / U+E / ESR / PV / TFT / glucose / cholesterol
- Plasma protein electrophoresis
Other test to consider:
- Thrombophilia screen – thrombin time, prothrombin time, activated partial thromboplastin time, protein C & S, factor V Leiden mutation, prothrombin mutation, anticardiolipin antibody (IgG and IgM), lupus anticoagulant
- Autoantibodies – rheumatoid factor, ANA, anti-DNA antibody
- Syphilis serology
- Carotid dopplers
- Variable VA presentation.
- Flame-shaped +/- dot blot haemorrhages with retinal oedema and cotton wool spots
Investigations: OCT, FFA, OCTA
- 6 months – 50% VA 6/12 or better.
- 25% less than 6/60 vision.
Complications of RVO:
- Chronic macular oedema
- Macular ischaemia
- Neovascularisation – 40% of eyes > 5 disc diameter of non-perfusion.
- Medical treatment – treat systemic risk factor or hypercoagulable state (anticoagulant)
- Laser treatment – BVOS: macular laser after 3-6 months observation, good macular perfusion and vision 6/12 or worse. PRP if signs of neovascularisation.
- Steroid treatment – SCORE: only use IVTA in refractory and pseudophakic cases; GENEVA: Ozurdex for macular oedema (last 3 months)
- Anti-VEGF treatment – BRVO (ranibizumab) study – ranibizumab is superior to laser for macular oedema ; BRIGHTER study – ranibizumab + laser made no difference to macular oedema ; BERVOLT study – bevacizumab is safe for macular oedema associated BRVO ; VIBRANT study – aflibercept is superior to laser for macular oedema
- Surgical treatment – PPV for BRVO related vitreous haemorrhage or tractional retinal detachment.
Pathway for treatment:
- Observe for 2-3 months for VA progression and neovascularisation
- Macular oedema present – anti VEGF for first 3 months then see response.
- If not improving macular oedema – consider steroid treatment
- If still not response – consider grid macular laser.
- If signs of neovascularisation – PRP
CENTRAL RETINAL VEIN OCCLUSION
Demographics: Usually unilateral; M=F; >65 years old; Annual risk of 1% in fellow eye.
- Sudden painless loss of vision
- Check for NVI and NVA (NVA appears in 12% on first presentation)
- Raised IOP – risk NVG – ‘100 day glaucoma – neovascularisation within 3 months of CRVO‘
- Flame shaped & Dot/blot haemorrhages in all 4 quadrants of retina
- Other changes in retina – macular oedema, cotton wool spots, optic disc oedema, vitreous haemorrhage or NVD/NVE.
- Chronic changes (6-12 months) – collaterals, venous sheathing & sclerosis at site of obstruction, RPE changes or ERM.
Investigations: FFA; OCT
Central retinal vein occlusion study (CVOS):
- Visual acuity 6/12 or better – maintained their vision.
- Poor visual acuity presentation (6/60 or worse) – 20% improvement chance.
- NVA without NVI in 12% of cases.
- Perfused (non-ischaemic) 80% cases vs. Non-perfused (ischaemic) 20% cases.
- Primary treatment – Systemic treatment (BP, DM); hypercoagulable states.
- Macular oedema treatment – observation (first few weeks); SCORE study (IVTA useful – this study led to to the use of Ozurdex); CRUISE study (ranibizumab use – RETAIN study shows ranibizumab use maintain condition in < 1/2 patients at 4 years); COPERNICUS & GALILEO study (aflibercept use maintain vision long-term when used early); Bevacizumab (off license use)
- Neovascularisation treatment: PRP for signs of NVI/NVA/NVD/NVE; topical/systemic anti-glaucoma agents; cycloplegic agents; surgery if IOP uncontrolled; anti-VEGF prior to PRP as adjunct (note: PRP best perform within a week after anti-VEGF).
- Non-clearing vitreous haemorrhage: PPV + endolaser PRP.
ACE: angiotensin converting enzyme; ANA: Antinuclear antibody; BP: Blood pressure; BRVO: Branch retinal vein occlusion; BVOS: Branch Vein Occlusion Study; CRF: Chronic Renal Failure; CRP: C-reactive protein; CXR: chest X-ray; DM: Diabetes Mellitus; ECG: electrocardiogram; ESR: erythrocyte sedimentation rate; ERM: epiretinal membrane; FBC: Full blood count; FFA: fundus fluorescein angiogram; GENEVA: Global Evaluation of Implantable Dexamethasone in Retinal Vein Occlusion with Macular Edema; HTN: hypertension; IOP: Intraocular pressure; IVTA: intravitreal triamcinolone; NVA: neovascularisation of angles; NVD: neovacularisation at disc; NVE: neovascularsiation elsewhere; NVG: neovascular glaucoma; NVI: neovascularisation of iris; OCP: oral contraceptive pills; OCT: optical coherence tomography; OCTA: optical cohorence tomography angiography; PPV: pars plana vitrectomy; PRP:panretinal photocoagulation; PV: plasma viscosity; RAPD: relative afferent pupillary defect;RPE: retinal pigment epithelium; RVO: retinal vein occlusion; SCORE: standard care versus corticosteroids for retinal vein occlusion; TFT: thyroid function test; U+E: urea and electrolytes; VA: visual acuity