Scotoma is characterized by the total or partial loss of the ability to see a region of the visual field, which is usually surrounded by an area where vision is preserved.
All people have a scotoma in their field of vision, which is called a blind spot and is not consciously perceived by the person himself, nor is it considered pathological.
A pathological scotoma can involve any part of the visual field and can come in many shapes and sizes, and in some cases it can cause a loss of much of the vision. However, if scotomes are located in peripheral regions, they may even go unnoticed.
Possible causes
The causes that can lead to scotoma formation can be lesions in the retina and optic nerve, metabolic diseases, nutritional deficiencies, multiple sclerosis, glaucoma, changes in the optic nerve, changes in the visual cortex, arterial hypertension and exposure to toxic substances.
In some cases, the appearance of scotomas in pregnancy can be a sign of severe pre-eclampsia. Find out what preeclampsia is and how to identify it.
Types of scotoma
There are several types of scotoma, most of which are permanent. However, the type associated with a migraine is temporary and lasts only an hour and is often part of the aura of headache.
The most common types of scotoma are:
- Scintillating scotoma, which occurs before the onset of a migraine, but which can also occur alone. This scotoma appears as a sparkling arc-shaped light that invades the central visual field; Central scotoma, which is considered the most problematic type and is characterized by a dark spot in the center of the field of vision. The remaining visual field remains normal, causing the person to focus more on the periphery, which makes daily activities very difficult; Peripheral scotoma, in which a dark patch is present along the edges of the field of view, which although it may interfere slightly with normal vision, it is not so difficult to deal with a central scotoma; Hemianopic scotoma, in which half of the visual field is affected by a dark patch, which can occur on both sides of the center and can affect one or both eyes; Paracentral scotoma, where the dark spot is located close, but not in the central visual field; Bilateral scotoma , which is a type of scotoma that appears in both eyes and is caused by some type of tumor or brain growth, being very rare.
What are the signs and symptoms
Generally, people who have a scotoma, have a spot in their vision, which can be dark, very light, cloudy or sparkling. In addition, some of them may experience some difficulties in vision, difficulties in distinguishing some colors or even need to have more light, to see more clearly.
How the treatment is done
The treatment of scotoma depends on the root cause. Therefore, it is important that the ophthalmologist makes a diagnosis in order to be able to treat the disease that is causing this problem.
