Branch Retinal Vein Occlusion (BRVO)
Background
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BRVO is three times as common as CRVO
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may affect superotemporal / superonasal / inferotemporal / inferonasal arcade
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​arcade = ​large bundles of retinal vessels - arterial and venous​
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superotemporal arcade is most commonly affected​ by BRAO
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BRAO typically arises from a point where a retinal arteriole crosses over a branch of a retinal vein (known as a 'nipping point')
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BRVO occurs as a result of atherosclerotic disease within the arteriole wall which causes vessel damage and thrombus formation within the retinal vein branch
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Presentation
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​may be asymptomatic
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visual changes will occur if the macula is affected​
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reduced visual acuity
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visual field defect
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metamorphospia (distortion of vision)
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Examination findings
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Examination of the retina in acute BRVO:
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cotton wool spots
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dot, blot and flame haemorrhages - confined to region that the affected vein branch normally drains
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oedema surrounding one engorged vein​ which follows a tortuous path
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oedema (fluid leakage from vessels leading to swelling) of the macula region of the retina
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Chronic changes:
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​​down the line, neovascularisation (new vessel growth) on the retina may occur
- these vessels can bleed into the vitreous (vitreous haemorrhage)​
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Treatment
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Conservative management if vision is preserved - observation
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Treat co-existing hypertension +- hyperlipidaemia
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Intravitreal steroid injection / implant
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anti-VEGF injections (helps to treat macula oedema and neovascularisation)
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Laser - photocoagulation, if there is neovascularisation
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References
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Denniston, A. K. O. and Murray, P. I. (eds) (2018) Oxford handbook of ophthalmology. 4th edn. London, England: Oxford University Press (Oxford Medical Handbooks). doi: 10.1093/med/9780198804550.001.0001.
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James, B., Bron, A. J. and Parulekar, M. V. (2016) Lecture Notes Ophthalmology. 12th edn. Nashville, TN: John Wiley & Sons (Lecture Notes)
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Salmon, J. F. (2019) Kanski’s clinical ophthalmology. 9th edn. London, England: Elsevier Health Sciences.