What is MS?

Multiple sclerosis (MS) is a neurological condition in which the body’s immune system mistakenly attacks the protein (myelin) that surrounds and protects the nerves. It affects the brain and spinal cord, causing a range of symptoms that can affect vision, balance and mobility. It is estimated that there are 130,000 people living with MS in the UK, with nearly 7,000 people newly diagnosed every year.1

What are MS eye symptoms?

Depending on which nerve is affected, MS can cause various eye symptoms, including:

  • Double vision
  • Pain when you move your eyes
  • Involuntary eye movements
    (flicking rapidly from side to side or up and down)
  • A blind or blurred spot in your central vision
  • Colours can look darker or ‘washed out’
  • Flashes of light when you move your eyes
  • Vision loss in affected eye
  • Feeling that things are spinning (vertigo)

Symptoms may vary depending on the severity of the condition and how recently you have been diagnosed.

How does MS affect the eyes?

Some eye conditions are commonly associated with multiple sclerosis. The most common vision problems are to do with eye movement. Fortunately, the prognosis is good for recovery from many of the vision problems that are associated with MS, as listed below.

Optic Neuritis

Optic neuritis is an inflammation of the optic nerve — the part of the eye that carries signals to the brain. For around 1 in 5 people with multiple sclerosis, optic neuritis is their first symptom.2

In MS, optic neuritis occurs when the immune cells mistakenly attack the myelin sheath that surrounds and protects the optic nerve, causing it to swell. This can cause damage to the optic nerve and disrupt the signal between the eye and the brain so that visual information is not interpreted correctly. Sometimes, this can include blind spots, where both eyes leave out a section of the visual field.

Double vision (diplopia)

When the nerves that control your eye movement become inflamed or damaged due to MS, it can also mean that the eyes don’t work together properly to form clear images. This can lead to double vision, a condition that causes you to see two images of a single object. Double vision in both eyes is known as binocular diplopia and is most common, whereas double vision in one eye is known as monocular and is the least common of the two.

Nystagmus

Optic nerve damage can also lead to nystagmus — the involuntary movement of the eyes that causes them to flick rapidly from side to side, up and down, or around.

Often, this can be very subtle, without affecting your vision, but in some cases, it can cause the sensation that the environment around you is moving or wiggling – this is called oscillopsia – and might also make you feel quite sick or affect your balance.

Nystagmus in MS patients may also be caused by nerve damage to the parts of the brain that coordinate balance, muscle movements and vision.

Can an optician detect MS?

Only a neurologist (a specialist in nerves and the nervous system) can make a diagnosis of multiple sclerosis. But many people will start their journey with an optician, as eye problems are a common first symptom. MS can present itself in many different ways, but eye problems are often the first symptom in many people or, if not, it’s likely that people with MS will experience eye problems at some point, which is why regular eye tests are so important.

There are certain things that can signal the early signs of MS during an eye test, and if an optician spots something unusual, they’ll refer you on to an ophthalmologist (eye specialist) for further tests and to rule out other causes. Then, if there is further cause for concern, the ophthalmologist would hand you over to a neurologist.3 So it’s important to have regular eye tests to keep an eye on any changes over time, but also to see your optician whenever you have any changes in your vision.

Can an OCT scan help to detect MS?

OCT (optical coherence tomography) is a very useful tool in detecting signs of optic neuritis, a common early symptom in MS patients. This is because it allows the optometrist to get a really good look at the health of the optic nerve, as well as the thickness of the retinal layers.

The retinal nerve fibre layer (RNFL) thickness is a good indicator of optic neuritis, and your optometrist will be looking for a thinning of this layer which shows a loss of nerve fibres. RNFL thickness can also be useful to measure for a range of neurological conditions, including MS, with studies showing that MS patients tend to have a thinner RNFL compared with healthy subjects.4 Just ask your optician about adding an OCT scan to your normal eye test.

It's important to note that diagnosing multiple sclerosis involves a wide range of tests, and eye tests and OCT scans are just a small part of this process. There’s also a lot of ongoing research that suggests OCT can be helpful for established cases of multiple sclerosis, with research suggesting that the loss of nerve fibres in the eye could reflect the effects multiple sclerosis has on the brain, in effect mirroring the changes. OCT could therefore be an important part in the ongoing monitoring of MS as well as measuring the success of treatment and trials.4,5

Treatment for MS eye symptoms

Most eye conditions that are caused by MS improve on their own over time, yet some people can find the symptoms hard to manage. For the conditions previously mentioned, various treatments are available:

Optic Neuritis treatment

One way to detect optic neuritis is by performing an OCT scan, this enhanced eye examination can be added to your routine eye test. If your optometrist suspects you have optic neuritis, they’ll refer you to a hospital eye department where your diagnosis will be confirmed, and a treatment plan developed.

Diplopia treatment

Treatment ranges from simple eye exercises or prism lenses to minor surgery. A contributing factor to this is whether your double vision is monocular or binocular.

For binocular double vision, glasses with lenses incorporating prisms can be used to help the eyes align the two images into a single image. Sometimes, temporarily, an eye patch can help, as can minor surgery.

Because monocular diplopia is quite rare, treatment will depend very much on the cause. Your optician will help to determine the right solution and suggest the best treatment for you. In some cases, they may recommend you visit your GP or hospital eye department for treatment. For more information head to our double vision page.

Nystagmus treatment

There’s no cure for nystagmus at the moment, but some of its underlying conditions can often be treated. It’s mostly about learning to cope with its effects. The following may be recommended to you:

●      Glasses and contact lenses

●      Medication

●      Surgery

Consistently taking medication to relieve symptoms of MS can help - some medications can reduce the side effects of vision problems and the flare-ups they can cause. You can find more information, advice and support around nystagmus at Nystagmus Network.

Other options are also available and will be recommended to you depending on the severity of your condition. If you ever have any concerns about your vision or eye health, get in touch with your local store to book an eye test.

How can home eye exams support people with MS?

Besides vision problems, mobility impairment (particularly difficulty walking) is one of the most common effects of multiple sclerosis. We understand that this can have an impact on your ability to carry out daily activities, and can make it very difficult to access eyecare without assistance or dependence on a carer. 

Home eye tests are essential for people with MS who are unable to leave their homes unaccompanied. Our visiting opticians can use a range of specialist equipment adapted for use in the home to carry out a full eye test, tailored to your eyecare needs and performed where you’re most comfortable.

You’re also more than welcome to have any carers or family members present during your exam to make sure you feel as relaxed as possible.

How do opticians test for MS vision problems at home?

Typically, patients with multiple sclerosis have a longstanding diagnosis before they use home eye tests. This means that many eye problems related to the condition will have been previously assessed and diagnosed by a doctor or optician. Our visiting opticians provide a range of support for MS patients at home — such as managing and amending glasses prescriptions — as well as visiting patients to check up between hospital appointments. They use a range of eye tests to help assess the overall health of your eyes:

Visual acuity test

A visual acuity test assesses your ability to see detail at a distance. You’ll be asked to read from an electronic letter chart, and you’ll also wear a pair of trial glasses to test your vision with different strength lenses. This helps to check your general vision and detect any vision loss caused by optic neuritis in MS patients.

Eye muscle testing

Your optician will ask you to sit comfortably while you stare at an object in front of you (usually a pen). They will move the object up and down and side to side and ask you to follow the object with your eyes while keeping your head still. This test helps your optician to check for diplopia (double vision) and nystagmus (dancing eyes), which are common MS eye problems.

Retinal and optic nerve assessment 

To test the health of the back of your eyes (including the optic disc) at home, they will be examined using a direct ophthalmoscope. If your pupils are small, you may have drops administered to make them larger, allowing your optician to take a closer look using an ophthalmoscope. If they notice any signs that need further investigation, they can refer you to your GP or local hospital. Learn more about our full home eye test process here.

Are MS patients eligible for free home eye tests?

If you have MS and experience mobility impairment, you may benefit from a free NHS-funded home eye test. You can check the eligibility criteria on our website to see whether you qualify, or visit our Home Visits page for more information on how we can support your needs.

Noticed a change in your vision?

If you’re experiencing any of the symptoms we’ve mentioned above, it’s worth booking an appointment with one of our optometrists — they might even recommend an OCT scan to get a closer look. For information regarding other eye conditions and their symptoms visit our eye conditions hub.

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References

  1. MS Society (2021) MS in the UK. Available at: https://www.mssociety.org.uk/what-we-do/our-work/our-evidence/ms-in-the-uk [Accessed 22 November 2021]
  2. MS Trust. (2018) Visual Problems. Available at: https://www.mstrust.org.uk/a-z/visual-problems. [Accessed 1 April 2020]
  3. NICE. (November 2019) Multiple sclerosis in adults: management. [Online]. Available at:https://www.nice.org.uk/guidance/CG186/chapter/1-Recommendations#diagnosing-ms-2 [Accessed 11 March 2020].
  4. Cédric Lamirel, Nancy J. Newman, and Valérie Biousse. (2010) Optical Coherence Tomography (OCT) in Optic Neuritis and Multiple Sclerosis. [Online]. Available at:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3005938/ [Accessed 15 March 2020]
  5. National MS Society (2015). Leading Edge Collaboration in Eye-Related Research Earns Investigators at NYU Langone Medical Center, Johns Hopkins, and the UT Southwestern Medical Center the 2015 Barancik Prize for Innovation in MS Research. [Online]. Available at: https://www.nationalmssociety.org/About-the-Society/News/Leading-Edge-Collaboration-in-Eye-Related-Research [Accessed 15 March 2020]