Stroke-Induced Scotoma: Understanding Visual Field Loss

Scotomas are blind spots that obstruct a person's field of vision. They are caused by anomalies in the neurological signals being sent from the eye to the brain. A stroke can cause a scotoma by damaging the brain or the nerves and muscles around the eye. Scotomas can also be caused by other factors such as migraines, high blood pressure, and hormonal changes.

Scotomas are blind spots that can affect one or both eyes

Scotomas are a common occurrence after a stroke. Vision changes or vision loss can occur after a stroke because the stroke has injured part of the brain or affected the nerves and muscles around the eye itself. Scotomas can be a symptom of damage to any part of the visual system. They can be caused by issues with the retina, brain, and/or optic nerve.

There are several different types of scotomas, including central, scintillating, paracentral, and junctional. Central scotomas occur when the blind spot is in the middle of your vision. Scintillating scotomas often appear jagged or wavy and can go from light to dark. Paracentral scotomas occur when the blind spot is within 10 degrees of fixation, or slightly off to the side of where you're looking. Junctional scotomas happen because of damage to the place where the optic nerve and the optic chiasm come together.

The symptoms of a scotoma may include a spot where your vision is blocked or disturbed, difficulty seeing certain colors, needing bright light to see well, and eye floaters and flashes. If you are experiencing any changes or worsening of your vision, it is important to contact your healthcare provider.

They are caused by damage to the visual system, including the retina, optic nerve, and brain

Scotomas are blind spots in the field of vision. They are caused by damage to the visual system, including the retina, optic nerve, and brain.

The retina is a layer at the back of the eye that converts light into electrical signals. These signals are then sent to the brain via the optic nerve. Scotomas occur when there is an abnormality in this process, resulting in a blind spot in the field of vision. This can be caused by a variety of factors, including retinal damage, optic nerve damage, and brain damage.

Retinal damage can be caused by exposure to high-powered lasers, retinal burns, diabetic retinopathy, and age-related macular degeneration. Optic nerve damage can be caused by conditions such as multiple sclerosis, optic neuritis, and toxic substances. Brain damage, on the other hand, can be caused by stroke, traumatic brain injury, and tumours.

Scotomas can vary in size and location, and they can affect one or both eyes. They can be temporary or permanent, and they may or may not cause any pain. While some scotomas are benign and resolve on their own, others can indicate underlying health conditions such as migraine, glaucoma, multiple sclerosis, or preeclampsia.

It is important to consult a doctor if you experience any sudden changes in your vision or if you notice the presence of a blind spot. A comprehensive eye exam can help diagnose scotomas and underlying health conditions.

Scotomas can be positive or negative. Positive scotomas are visible, while negative scotomas are undetected by the patient

A scotoma is an area of partial alteration in the field of vision, consisting of a partially diminished or entirely degenerated visual acuity. Every normal mammalian eye has a scotoma in its field of vision, usually referred to as a blind spot. This is a location with no photoreceptor cells, where the retinal ganglion cell axons that compose the optic nerve exit the retina.

Scotomas can be positive or negative. A positive scotoma is when something like a spot, haze, or smoke obscures central vision. Patients with positive scotomas often describe the phenomenon as "snow falling through a beam of light". On the other hand, a negative scotoma is when the patient is unaware of the scotoma unless it is tested for. Patients with scotomas report that things disappear on them.

Scotomas can be caused by a stroke or other brain injury. About two-thirds of people experience some changes to their vision after a stroke. However, vision problems can improve over time as the brain recovers.

There are several types of scotomas, including central, scintillating, paracentral, and junctional

A scotoma is a blind spot in the field of vision, which can be temporary or permanent. Scotomas are caused by anomalies in the neurological signals being sent from the eye to the brain. They are related to the brain's inability to process the images from one area of vision.

• Central Scotomas: These are blind spots that occur directly in the centre of the visual field. They can appear as a dark spot, blurred vision, or a smudge in the centre of the eye. Central scotomas can cause problems with seeing colours and details, and can make tasks like driving and reading challenging or impossible.
• Scintillating Scotomas: These are visual blind spots that fluctuate between light and dark. They may affect one or both eyes and typically appear as floaters, dots, or blind spots. Scintillating scotomas are usually temporary and may be a symptom of an underlying health condition such as glaucoma or multiple sclerosis (MS). They are also commonly associated with migraines.
• Paracentral Scotomas: These are isolated vision loss spots within 10 degrees of fixation, meaning they are not in the central field of vision. They are typically caused by glaucoma and can lead to tunnel vision.
• Junctional Scotomas: These occur when the place where the optic nerve and optic chiasm meet is damaged. The optic chiasm is the part of the brain where the optic nerve enters the brain. Junctional scotomas typically present as a central scotoma in one eye and temporal field loss in the other, with the extent of vision loss depending on which part of the optic nerve is damaged.

Scotomas can be temporary or permanent, and their treatment depends on the underlying cause

A scotoma is a blind spot in your vision that can obstruct part of your vision field. It can be a symptom of damage to any part of the visual system, including the retina, optic nerve, or brain. Scotomas can be temporary or permanent, and their treatment depends on the underlying cause.

There are several types of scotomas, including central, paracentral, junctional, and scintillating scotomas. Central scotomas are blind spots in the middle of your vision, which can make reading, driving, and recognizing faces difficult or impossible. Paracentral scotomas are blind spots slightly off to the side of where you're looking, within 10 degrees of fixation. Junctional scotomas are caused by damage to the place where the optic nerve and the optic chiasm come together. Scotomas can also be positive or negative. Positive scotomas involve seeing something like a spot of a particular colour, while negative scotomas are blind spots that the affected person is unaware of.

Scotomas can be caused by various conditions, including multiple sclerosis, retinal injuries, age-related macular degeneration, medication side effects, glaucoma, diabetes-related retinopathy, retinal tears and detachments, migraine headaches, high blood pressure, hormonal changes, and cancer.

The treatment for scotomas depends on the underlying cause. For example, if a scotoma is caused by high blood pressure, treating the high blood pressure can help eliminate future blind spots. In some cases, scotomas may not require treatment and will resolve on their own. For instance, scintillating scotomas, which are often associated with migraines, usually last from a few seconds to 30 minutes and go away without treatment. However, if scotomas are caused by certain conditions like glaucoma, diabetes, macular degeneration, or neurological issues, there may not be a successful treatment. In these cases, low vision aids, such as proper lighting, magnifiers for reading, or equipment that can read aloud, may be prescribed to help manage the vision loss.

Frequently asked questions