Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be talking to you about retinal vein occlusion.

And you can find written notes on this topic at zero tofinals.com slash retinal vein occlusion or in the ophthalmology section of the Zero to Finals Medicine book. So let's get straight into it. Retinal vein occlusion or in the ophthalmology section of the zero definals medicine book. So let's get

straight into it. Retinal vein occlusion occurs when a blood clot or a thrombus forms in the retinal

veins at the back of the eye and blocks the drainage of blood away from the retina. The central

retinal vein runs through the optic nerve and it's responsible for draining blood from the retina. The central retinal vein runs through the optic nerve

and it's responsible for draining blood from the retina.

There are four branched veins that come together to form the central retinal vein.

And blockage in one of the branch veins causes a problem in the area drained by that branch,

whereas blockage in the central vein causes problems with the whole retina.

Blockage of a retinal vein causes pooling of blood in the retina,

and this results in leakage of fluid and blood, which causes macular edema and retinal hemorrhages. This results in damage to the

tissue in the retina and loss of vision. And it also leads to a release of something called

vascular endothelial growth factor or veg F, and this stimulates the development of new blood vessels,

which is called neovascularization.

And this in itself is harmful to the retina as well.

So how does it present?

Well, blockage of one of the retinal veins presents with sudden, painless loss of vision.

What are the risk factors?

The key risk factors are hypertension, high cholesterol diabetes, smoking, glaucoma and systemic inflammatory conditions like systemic lupus erythematosis.

Let's talk about the findings on phandoscopy. And phandoscopy examination is really the diagnostic tool that's used to diagnose retinal

vein occlusion.

And it gives the characteristic findings of flame and blot hemorrhages, optic disc edema

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