Transient Monocular Blindness (TMB), often referred to as amaurosis fugax, signifies a temporary loss of vision in one eye.
Ophthalmic Artery Occlusion Mechanism
This condition typically results from temporary blockage (occlusion) of blood flow to the eye. Small emboli, often composed of platelet aggregates, are common culprits.
Role of Ophthalmic Artery
The Ophthalmic artery is the primary blood supply to the retina and optic nerve. It arises directly from the internal carotid artery.
- Emboli originating from upstream sources (like atherosclerotic plaques in the carotid artery or cardiac sources) can travel through the circulation.
- When these emboli reach the Ophthalmic artery, they can cause a temporary occlusion.
- This occlusion interrupts blood flow to the retina, leading to the transient loss of vision characteristic of TMB.
Occlusion of the posterior cerebellar or posterior cerebral arteries typically affects different brain regions and causes different symptoms, such as vertigo or visual field defects, respectively. The vertebral artery supplies the brainstem and cerebellum, and its occlusion does not typically cause monocular blindness.
Therefore, small platelet emboli causing Transient Monocular Blindness most commonly occlude the Ophthalmic artery.
Important Questions from Stroke
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