What does optic neuritis have to do with MS?
If your vision suddenly becomes blurred, colors appear paler and darker, or you see double and your eyes hurt when you move, it may be an inflammation of the optic nerve, known as optic neuritis. If optic neuritis occurs in previously healthy people, it may be an early symptom of multiple sclerosis (MS).
Eye movement pain can be an indicator of optic neuritis.
Optic Neuritis – Symptoms and Course
Typical optic neuritis begins with pain when moving the eyes, followed by worsening vision. Visual acuity can decrease over several days, until it is almost completely lost. The perception of contrast and color vision can also be affected. In most cases, only one eye is affected. In contrast to other diseases of the optic nerve, such as a tumor, patients with optic neuritis can usually say exactly when the symptoms first appeared. This can be an important clue for diagnosis. If optic neuritis occurs for the first time, full vision is regained in most cases within two months. Chronic optic neuritis can lead to complete loss of vision.
How is optic neuritis diagnosed?
If an ophthalmologist looks at the affected eyes, in most cases he will see nothing. Only the papilla, the place where the optic nerve leaves the eye, can become slightly swollen if the inflammation is close to the eye. However, this is only the case in around a third of cases. The pupil reaction provides a clearer indication. When light hits the eyes, the pupils of both eyes constrict to the same extent. If optic neuritis is present, this reaction is different. If pain also occurs when moving the eyes, a relatively reliable diagnosis is made. In addition, color vision can be checked by looking at a colored image with one eye and then the other. Normally, the colors should appear the same in both cases, but if optic neuritis is present, the colors in the affected eye appear much darker and less saturated. Typical optic neuritis usually occurs between the ages of 18 and 50. Women are also more likely to be affected than men.
The cross section of the eye shows the position of the optic nerve.
optic neuritis and MS
About half of those affected develop multiple sclerosis within fifteen years of the onset of optic neuritis. In many cases, optic neuritis can be seen as the first bout of MS. The optic nerve is part of the central nervous system (CNS) and, like the other nerves of the CNS, is surrounded by a protective myelin layer. In MS, it is precisely this protective layer that is attacked by the patient's own immune system, causing inflammation to form on the sensitive nerves and leading to the typical impairments. Visual impairments are therefore one of the most common symptoms of MS. The diagnosis of optic neuritis should therefore always be followed by a detailed examination by a neurologist.
Uhthoff phenomenon
A common accompaniment to optic neuritis is the so-called Uhthoff phenomenon. It occurs in about half of those affected and usually in the regeneration phase. The Uhthoff phenomenon is the worsening of the symptoms of the disease, triggered by a rising body temperature, as can happen after physical activity or a hot bath. This phenomenon was first described in 1890 by the ophthalmologist Wilhelm Uhthoff. Originally related to the impairment of vision, today it is used to describe any worsening of MS symptoms caused by a rising temperature. The higher body temperature leads to reduced conductivity in damaged nerves. The worsening of the symptoms is therefore not due to new sources of inflammation and is also not persistent. In this case it is also referred to as a pseudo-attack.
What helps with optic neuritis?
The combination of pain during eye movement and worsening vision is so frightening for most people when it first occurs that they automatically do the only right thing - they go to the doctor immediately. Only a doctor can make the correct diagnosis, rule out other illnesses and arrange any necessary follow-up examinations. Even if you have MS, you should always see a doctor immediately if you experience acute vision problems, as this could be a new flare-up of the disease. A typical case of optic neuritis is treated with cortisone infusions to reduce the inflammation. Wearing sunglasses can also provide some relief.
