Retinal Vein Occlusion
BRANCH RETINAL VEIN OCCLUSION:
Main risk factors:
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
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
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.