Branch Retinal Artery Occlusions

What's going on?

The aetiology is similar to CRAO but in this situation the embolus was small enough to impact further into the retina, away from the disc. It may affect half the retina or only one quadrant of the retina. That part of the retina will die and there will be corresponding visual loss in that sector of the visual field. If the embolus impacts proximally enough to affect the macula then some central vision will be lost. Rarely, only the cilioretinal artery (an artery running straight from the optic disc to the macula) is affected, knocking off a small section of the macula. If the fovea is involved, visual acuity will be markedly reduced.

If I examine the patient, what will I find?

You may be able to see the glistening cholesterol or greyish fibrinoplatelet embolus in one of the branches of the retinal artery. The area of retina radiating distal to this blockage will be white-ish and oedematous in the early stages.

What if I've diagnosed it?

As for CRAO (see above).

What will the hospital do?

Attempts may be made to move the embolus further downstream by reducing the intraocular pressure, as in CRAO management.

What do I need to do?

As for CRAO.

What to tell the patient

The chances of recovering vision depend upon exactly how the embolus has impacted and how much damage it has done to the retina. They are at risk of further problems with clots and thus their cardiovascular risk factors need to be addressed.

Problems that may arise, and how to deal with them

The patient is at risk of formal stroke and so should be managed appropriately.