Eye symptoms commonly seen in multiple sclerosis
Vision problems can be one of the first signs of multiple sclerosis (MS) in some people.
The most common eye condition related to MS is optic neuritis
Vision problems can be one of the first signs of multiple sclerosis (MS) in some people. A common symptom is optic neuritis, or inflammation of the optic nerve (which connects the eye and brain). It can cause pain, vision loss, double vision, blurry vision and dim color vision.
Weakness of eye muscles and uncontrolled eye movements can also be symptoms of multiple sclerosis. Other symptoms of MS may include difficulty with balance, fatigue, numbness and weakness in the arms and legs.
What is multiple sclerosis?
Multiple sclerosis is a disease in which a person’s immune system mistakes its own healthy tissue as foreign and attacks it. MS affects the brain and spinal cord. This is known as the central nervous system (CNS). The CNS is the command center that sends electrical signals, via nerves, to all parts of the body. The eyes are also a part of the central nervous system.
During a flare up, nerve fibers and their surrounding protective fatty layer, called the myelin sheath, are attacked by the body. The immune system’s reaction to foreign tissue is inflammation. This inflammation damages the myelin sheath surrounding the nerves, in a process called demyelination. As a result, signals traveling in the injured part of the brain and spinal cord are interrupted or delayed.
The optic nerve transfers light signals from the retina, the light sensitive tissue in the back of the eye, to the brain — where they are processed as visual images.
During an attack, the optic nerve can become inflamed, a condition that is called optic neuritis. When this occurs, the nerve is not able to relay signals from the eyes to the brain very well.
Optic neuritis in multiple sclerosis usually occurs in only one eye, although it can occur in both. About half of people with MS develop optic neuritis at some point during the disease. Around 20% of people with MS have optic neuritis as the first sign of multiple sclerosis.
Symptoms can last 4-12 weeks, with greatest intensity within the first few days. Symptoms of optic neuritis include:
Pain with eye movement — This is often the first symptom of optic neuritis
Temporary blindness in one eye
Hazy area in center of vision
Dim or graying of color vision
Pulfrich phenomenon — an object swinging back and forth is seen as moving in a circle.
Uhthoff phenomenon — vision becomes worse when body temperature rises
A comprehensive eye and medical evaluation as well as imaging studies may be required to diagnose optic neuritis. Optical coherence tomography (OCT) is a non-invasive tool that can help to identify how the layers of the retina are affected by a flare up.
A team of doctors, such as an eye doctor and neurologist, may work together to manage and treat this condition. Special vision charts that use low contrast letters rather than the usual high contrast letters can be used to measure the degree of vision loss.
The severity and range of optic neuritis symptoms can vary. As a result, treatment differs for individual cases. In some instances, optic neuritis may go away by itself with no lasting vision complications. In other cases, a doctor may need to prescribe medications such as intravenous steroids to decrease the inflammation of the optic nerve and to more quickly improve vision.
Double vision (diplopia)
In an individual with multiple sclerosis, the brain stem can be affected in an episode of inflammation. Inflammation in this area can affect the nerves and portions of the CNS that control the muscles responsible for coordinating eye movement. Due to this, the eyes may not be able to work together as a team. When eye movements are not in sync, two different images are sent to the brain — resulting in distorted or double vision.
Double vision can cause dizziness and difficulty with balance in some people with MS. It can make reading much more difficult as well. People with MS may need medications or other treatments during an episode.
In many cases, symptoms of double vision will improve over time. Use of an eye patch or special glasses, called prism glasses, are sometimes recommended to manage double vision.
Nystagmus is uncontrollable rapid eye movements that can be up and down or side to side. As a result, a person may be disoriented and feel as if the room is moving. Nystagmus can occur due to inflammation of the brain stem or the cerebellum. Like double vision, it can lead to dizziness and difficulty with balance.
As with other episodes of demyelination, treatment with medications or other medical interventions may be required. In many people, the symptoms of nystagmus may improve over time.
Tilting the head at a certain angle can help some people to decrease the feeling of disorientation. However, if nystagmus continues for a longer period of time, medication may be needed to treat it.
Who is at risk?
Multiple sclerosis is not hereditary, although someone with a family member with MS is at higher risk. It is also not contagious. It is a chronic (lifelong) condition that can occur at any age.
MS is one of the most common neurological causes of disability in young people — and is most commonly diagnosed when a person is in their 20’s or 30’s. Women are 2-3X more likely to be diagnosed with MS than men.