Many things can cause a scotoma, or blind spot. Causes range from migraine headaches to retinal conditions to tumors. Treatment depends on what’s causing the scotoma.
Scotoma (pronounced skuh-tow-muh) is the medical term for a visual field abnormality, or a blind spot. Most of these blind spots happen in one eye, but they can happen in both eyes.
A scotoma may be a spot on the retina where the nerves don’t work and don’t send signals to your brain. There’s an abnormality in your field of vision: you temporarily or permanently can’t see as well or can’t see at all in a certain location.
A scotoma can happen with conditions that affect your optic nerve or certain areas in the brain.
The word “scotoma” is the Greek word for darkness. The term “visual field” refers to the entire area that you see.
Yes, there are several different types of scotomas. (Some people use the word “scotomata” for more than one scotoma.) The types may reflect where the blind spot occurs, like a central scotoma, and some may refer to a color that you see, like a xanthic scotoma.
There are also positive and negative scotomas. With a positive scotoma, you’ll see something, like a spot of a particular color. With a negative scotoma, you don’t know that you have a blind spot. Your healthcare provider will find a negative scotoma during testing. Terms can also refer to being in one eye (unilateral or monocular) or in two (bilateral or binocular).
Some types of scotomas include:
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Everyone has a scotoma at the point where the optic nerve goes through the retina. Usually, it’s not noticeable because your brain fills in the empty spot.
Signs and symptoms of a scotoma may include:
Many conditions can cause a scotoma. These include issues with your retina, brain and/or optic nerve. Causes include:
Central scotoma causes include:
Junctional scotoma causes include:
Paracentral scotoma causes include:
Scintillating scotoma causes include:
Your healthcare provider will ask you questions about your medical history and symptoms. They might also use the following tests:
If your provider suspects a certain disease is causing your scotoma, they may recommend other types of testing. These tests could include laboratory tests on your blood or imaging tests to find tumors.
Treating the scotoma involves treating the condition that’s causing it. This is especially true of conditions like glaucoma, macular degeneration, stroke and cancer.
Some scotomas don’t need treatment. For instance, you may be able to relieve some symptoms of scintillating scotomas by lying down to rest or drinking water.
If you have migraines and scintillating scotomas, your provider may suggest medications that range from over-the-counter (OTC) pain relievers to triptans to anti-seizure medications.
At this time, there’s no way to prevent a scotoma from happening in certain situations. In other cases, such as migraines, you may be able to prevent a scotoma with certain medications that prevent migraines.
If you do have conditions that may be associated with scotomas, it’s best to get regular eye examinations and to try to maintain good health. For instance, aiming for steady blood sugar levels if you have diabetes or managing your blood pressure if you have hypertension may help to ward off eye problems in general.
The outlook for a scotoma depends on what’s causing it. Some of these blind spots are temporary. If they are, they’ll go away once your migraine is over or your blood pressure becomes stable.
Other times, a disorder causes the scotoma. In these cases, the scotoma might not disappear and might even become larger.
Having a scotoma, especially a central scotoma, can interfere with your ability to read or to drive. You may want to discuss low vision aids with your provider. These include things like proper lighting, magnifiers for reading or equipment that can read to you.
You should contact your healthcare provider about any changes or worsening symptoms with your vision.
Call 911 or go to the nearest emergency room if you experience these scotoma symptoms:
A note from Cleveland Clinic
You may not know the term “scotoma” as well as you know the term “blind spot,” but they mean the same thing. A scotoma may refer to something that you see that isn’t there, or it could refer to something you don’t see that you should. Some scotomas aren’t noticeable to the people who have them. As with all conditions, it’s important to discuss any changes in your eyesight with your healthcare provider. If you have a condition that creates significant problems with your vision, talk to your provider about things that may help you, like support groups or tools to help with low vision.
Last reviewed by a Cleveland Clinic medical professional on 01/18/2023.
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