Central retinal artery occlusion
With thanks to Yusuf.
The central retinal artery is the first branch of the ophtalmic artery, which is the first intracranial branch of the internal carotid artery.
Causes
emboli – thrombotic, fat, amniotic fluid, air – AGE
thrombosis
vasculitis
compression in the orbit – retroorbital haematoma; thyroid exophtalmos
trauma
sickle-cell crisis
Symptoms: severe loss of vision that develops over seconds; painless
Examination: decreased VA; prominent afferent pupillary defect; fundoscopic exam: macular cherry red spot (fovea – sparred) with a pale retina and less pronounced arteries
Treatment: depends on the cause
Thromboembolic causes: aim to dislodge the clot from the main artery to one of its branches:
– digital massage (digital pressure through closed eyelids for 10 – 15 sec then sudden release)
– vasodilation (by increasing pCO2 – rebreathing into a paper bag)
– lowering intraocular pressure – topical Bblockers; iv acetazolamide; anterior chamber paracentesis
Vasculitis: corticosteroids (1 – 2 weeks to loss of vision in the other eye if not treated)
Sickle-cell crisis: iv fluids, reverse precipitant cause
Decompression sickness: hyperbaric therapy
They all need urgent Ophtalmology referral.