If not treated promptly, a stroke that affects vision may lead to permanent partial or complete vision loss. It is important to note that vision loss can be both a symptom of a stroke as well as damage resulting from a stroke. If you or someone you know has sudden vision loss — whether partial or complete — seek immediate medical attention, as this is a true medical emergency and time is of the essence. One-quarter of all stroke patients will experience vision loss, but many will never fully recover their vision; however, patients who seek treatment within three hours from the onset of symptoms have a significantly higher chance of recovery than those who wait.
WHAT TYPE OF VISION LOSS IS ASSOCIATED WITH STROKE?
There are three primary types of vision loss associated with strokes:
- Hemianopia — This vision loss results in a stroke on one side of the brain or the other. It will appear as if half the field of vision in both eyes is lost. You will either lose the right half of your vision or the left half of your vision, and it will be lost in both eyes.
- Quadrantanopia — This type of vision loss will result in a quarter of the field of vision being lost in each eye.
- Scotoma — In this type of vision loss, there will be a large spot of vision missing somewhere in the visual field, but it will not be regular such as half or a quarter of the field of vision.
WHAT OTHER TYPES OF EYE DAMAGE RESULT FROM A STROKE?
In addition to causing vision loss, a stroke may also affect the nerves controlling the movement and other sensations of the eye. These can not only cause discomfort but also difficulty in visual activities even if there is no loss of vision. The most common of these problems are:
- Loss of eye movement — Nerves controlling movement of the eye may be damaged resulting in the inability of one eye to move properly. This results in either the inability of both eyes to look in the same direction at the same time or in double vision.
- Still objects may appear to be moving — Strokes in the brain stem may disrupt stability of vision. This will make tasks such as reading difficult as still objects will appear to be moving.
- Loss of feeling on the surface of the eye — If the surface of the eye loses feeling, natural tasks such as blinking will become difficult and the eyelid may no longer close properly or completely. A droopy eyelid and blurred vision are typical.
- Loss of visual comprehension — Visual agnosia is the loss of the brain to recognize or comprehend visual information. It makes recognizing or understanding common or familiar objects difficult. Recognizing familiar faces will be impaired.
Next time, we will discuss how stroke-related vision loss is treated as well as the broader signs of a stroke. Remember, a stroke is an emergency, and seeking medical attention immediately is imperative to increasing your odds of recovery. If you suspect that you or someone else may be having a stroke, call 9-1-1 right away. If you are not suffering from these symptoms but would like to learn more about strokes and vision, call Silverstein Eye Centers today at 816-358-3600.