VISION LOSS: TEMPORARY BLINDNESS

49

If your vision suddenly goes dark, whether completely or partially, it might be due to another underlying issue. The reasons behind it and what you should do vary depending on the extent of your vision loss.

If you experience an abrupt, complete, or near-complete loss of vision, it’s critical to treat it as an emergency. Dial the emergency number immediately because time is of the essence in getting a diagnosis and treatment. Don’t wait to see if it resolves on its own.

Emergency Situation: Sudden Total or Near-Total Vision Loss

This type of vision loss could occur if a clot blocks the retinal artery, termed as “central retinal artery occlusion” or “branch retinal artery occlusion.” It also signals a heightened risk of stroke or heart attack. Similarly, a clot blocking a blood vessel in the eye mirrors how a clot can lead to a heart attack if it obstructs the coronary arteries. If this happens in the brain, it’s referred to as an “ischemic” stroke.

Clots can trigger temporary blindness in one eye, typically lasting for 20 to 30 minutes. This phenomenon is often described as a “curtain of darkness” falling (known medically as “amaurosis fugax”). Without prompt intervention, this blockage could result in permanent blindness.

Treatment of Sudden Total or Near-Total Vision Loss

Treatment may involve medication to dissolve the clot or angioplasty, a procedure to reopen the blocked blood vessel. Additionally, it serves as a warning to reduce your risk factors for a heart attack or stroke.

Temporary, Partial Vision Loss

Similar to sudden total loss, any temporary or partial vision loss requires immediate attention, preferably in the emergency room. Causes for partial vision loss could include:

1. Migraines: These are the most common reasons for short-term, partial vision loss. Migraines may cause “aura,” affecting vision in both eyes with symptoms like flashing lights, shimmering spots, or blind spots.
2. Retinal migraine: This rare condition affects only one eye and typically causes partial or total blindness for a brief period, often during or before a headache. It’s usually harmless to your vision.
3. Retinal Vasospasm: This condition, like migraines, can lead to temporary vision loss. It occurs when a blood vessel in the retina constricts, reducing blood flow. Treatment can fully restore vision.
4. Closed-Angle Glaucoma: When the iris of the eye bulges, it can hinder fluid drainage, leading to increased eye pressure. Symptoms include discomfort, nausea, blurred vision, halos, or blindness in one eye. Prompt treatment is necessary to prevent permanent blindness.
5. Giant Cell Arteritis: Though uncommon, this condition is a significant cause of vision loss in people over 50. It involves inflammation of the artery linings, particularly in the head, with symptoms such as head pain, scalp tenderness, jaw pain, fever, and fatigue. Without treatment, it can result in permanent blindness within weeks.

Treatments for Partial Vision Loss

Treatment for giant cell arteritis typically involves corticosteroids like prednisone, with the possibility of long-term treatment. Additionally, a medication called tocilizumab (Actemra) is approved to aid in treating this condition.

If diagnosed promptly and treated accordingly, many of these causes of temporary vision loss can be managed effectively, preserving your eyesight and overall health.

Rare Causes of Temporary Vision Loss

While less common, certain conditions can still lead to temporary vision loss, though they are unlikely culprits.

Retinal Vein Occlusion: This occurs when a vein in the retina becomes blocked, often due to a blood clot. It can result in fluid buildup or leakage in the eye, along with swelling. Some individuals may experience episodes of temporary vision loss before developing this condition. It’s more prevalent in individuals with diabetes and those with health conditions affecting blood flow, such as high blood pressure.

Treatment may involve corticosteroid injections to manage inflammation. In some cases, additional interventions like anti-vascular endothelial growth factor drugs or laser treatment may be necessary to address fluid accumulation.

Epileptic Seizures: Approximately 5% to 10% of people with epilepsy experience seizures that impact the occipital lobe, responsible for vision control. Consequently, these seizures can trigger vision loss during and after the episode. For individuals with epilepsy, treatment is recommended to prevent such complications.

Papilledema: This condition arises when increased pressure in the brain causes swelling of the optic nerve. It can lead to vision alterations such as double vision, blurriness, and brief blindness, typically lasting a few seconds. Other symptoms may include headaches and vomiting. Papilledema may stem from various causes such as tumors, abscesses, or blood clots, while factors like high blood pressure, infections, or certain medications can also exert pressure on the brain.

Uhthoff Phenomenon: Exclusive to individuals with multiple sclerosis (MS), Uhthoff phenomenon is a rare occurrence even among MS patients. MS damages nerves, rendering them more susceptible to heat sensitivity. With this phenomenon, an increase in body temperature exacerbates symptoms, including temporary vision loss in one or both eyes. Additional sensations like weakness, numbness, or dizziness may accompany it. Triggers for Uhthoff phenomenon encompass activities such as exercise, exposure to heat or sun, fever, and stress. Proper management of MS through treatment can help prevent such complications.

These rare causes of temporary vision loss underscore the importance of thorough evaluation by medical professionals to determine appropriate interventions and prevent potential long-term consequences.

Sources:

1. Clinical Ophthalmology
2. Medscape: “Transient Vision Loss (TVL).”
3. National Institutes of Health, National Center for Advancing Translational Sciences: “Papilledema.”
4. Harvard Health: “Optic Nerve Swelling (Papilledema).”
5. The Johns Hopkins Vasculitis Center: “Giant Cell Arteritis.”
6. American Academy of Ophthalmology: “Giant Cell Arteritis.”
7. Mayo Clinic: “Giant Cell Arteritis.”
8. Mayo Clinic: “Ocular Migraine: When to Seek Help.”
9. American Migraine Foundation: “Understanding Ocular Migraine.”
10. Epilepsy Foundation: “Occipital Lobe Epilepsies.”
11. Mayo Clinic: “Dry Eyes.”