From the Guidelines
Transient blindness can be caused by various conditions, including cataracts, glaucoma, retinal or choroidal detachments, vitreous or anterior segment hemorrhage, drusen, hypercoagulability syndromes, primary vasospasm, blepharospasm, and metabolic derangements, as identified in the most recent study 1.
Common Causes of Transient Blindness
The causes of transient blindness can be diverse and may involve:
- Cataracts
- Glaucoma
- Retinal or choroidal detachments
- Vitreous or anterior segment hemorrhage
- Drusen
- Hypercoagulability syndromes
- Primary vasospasm
- Blepharospasm
- Metabolic derangements, such as those seen with glucose imbalance, as noted in the study 1.
Importance of Ophthalmologic Evaluation
A complete ophthalmologic evaluation is necessary to diagnose these conditions, and cross-sectional imaging is usually not necessary in cases where glaucoma, cataract, or macular degeneration are identified 1.
Other Conditions
Other studies have mentioned additional causes, such as amaurosis fugax, which is caused by temporary reduction of blood flow to an eye, often due to atherosclerosis of the ipsilateral internal carotid artery, or other causes like carotid artery stenosis or occlusion, dissection, arteritis, radiation-induced arteriopathy, embolism, hypotension, intracranial hypertension, glaucoma, migraine, and vasospastic or occlusive disease of the ophthalmic artery 1. However, the most recent and highest quality study 1 prioritizes the causes mentioned earlier, emphasizing the importance of a thorough ophthalmologic examination in diagnosing the underlying cause of transient blindness.
From the FDA Drug Label
Reports of transient and permanent blindness and significant partial vision loss have been reported with the use of 5-HT1 agonists Since visual disorders may be part of a migraine attack, a causal relationship between these events and the use of 5-HT1 agonists have not been clearly established.
The common causes of transient blindness are not clearly established in the context of sumatriptan use. Possible causes may include:
- Migraine attacks: Visual disorders may be part of a migraine attack.
- Vasospasm reactions: Sumatriptan tablets may cause non-coronary vasospastic reactions. However, the FDA drug label does not provide a direct answer to the question of common causes of transient blindness 2 2.
From the Research
Common Causes of Transient Blindness
- Transient monocular blindness (TMB) or amaurosis fugax is often caused by atherothromboembolism from the origin of the internal carotid artery (ICA) 3
- Other potential causes of TMB include:
- Anterior optic nerve ischemia, usually caused by thrombosis in the posterior ciliary artery 3
- Thrombosis in the central retinal vein 3
- Dissection of the ICA, vascular malformations, or fibromuscular dysplasia 3
- Atheromatous plaque at the carotid bifurcation in the neck liberating emboli or causing a temporary reduction in carotid and retinal blood flow 4
- Retinal ischemia secondary to carotid embolism, thrombosis, hemodynamic disorders, or vasospasm 5
Diagnosis and Management
- TMB should be investigated and treated in the same way as neurologic transient ischemic attacks (TIAs) with emphasis on rapid detection of extracranial arterial disease, cardiac abnormalities, and haematological disorders 4
- All TIAs, including amaurosis fugax, should be treated as medical emergencies and managed with stroke prevention strategies, including antiplatelet therapy, lifestyle modifications, and management of traditional risk factors such as hypertension, dyslipidemia, and diabetes 6
- Explicit diagnostic criteria for TIAs can improve sensitivity and specificity of diagnoses and differentiate TIAs from migraine with aura 7