When The Optic Nerve Falters: Diagnosing + Treating Optic Neuropathy

Optic neuropathy is an eye condition that occurs when there is inflammation in the optic nerve. This inflammation can cause complications such as pain, swelling, and vision loss. In addition to these potentially severe symptoms, optic nerve inflammation is linked to conditions like multiple sclerosis and other autoimmune diseases.

To prevent damage to their eyes and the onset of other health conditions, patients should understand some basic facts about optic neuropathy and the treatments available.

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Optic neuropathy occurs when inflammation affects signals traveling through a patient’s optic nerve. The optic nerve is the part of the eye that carries messages from a patient’s eyes to their brain. This allows the brain to react and interpret visual signals.

When the nerves that carry these signals become inflamed, it disrupts the flow of messages from the eyes to the brain. This can cause difficulty seeing, as well as lead to more severe symptoms such as vision loss.

Symptoms for optic neuropathy can occur in one or both eyes. Depending on the patient and their condition, these symptoms may arise gradually or appear suddenly. Some common symptoms include:

Eye pain: Pain typically occurs in the back of the eye socket and becomes more intense when patients move their eye.

Loss of visual acuity: Patient’s vision may become blurred or less clear.

Flashing lights: Patients see flashing or flickering lights when moving their eye.

Loss of color vision: A general decrease in color vision. Colors may appear less bright or vivid than they once were.

Related: When One Eye Sees Clearly + The Other Doesn’t: Causes Of Blurry Vision In One Eye

When left untreated, symptoms usually get worse. This makes it crucial that patients contact their eye doctor as soon as they notice any symptoms associated with optic neuropathy.

The specific cause of optic neuropathy is still unknown. Experts believe optic neuropathy may occur when the immune system accidentally targets the substance covering the optic nerve, leading to inflammation.

Optic neuropathy has been linked to a range of other conditions and substances, including:

Autoimmune disorders: Optic neuropathy is associated with a variety of autoimmune disorders, the most common of which is multiple sclerosis (MS). MS occurs when the autoimmune system attacks sheaths of nerve cells in the brain. Around half of people who have an episode of optic neuritis develop MS during their lifetime.

Autoimmune disorders like neuromyelitis optica and myelin oligodendrocyte glycoprotein (MOG) are also linked to optic neuropathy.

Infections: Infections can cause damage to the nerves in the eye and around the body. Viral infections often trigger nerve damage that leads to optic neuropathy.

These may include conditions such as lyme disease, cat-scratch fever, and syphilis. Viruses such as measles, mumps, and herpes can also cause optic neuropathy.

Drugs & Medications: Certain prescription and non-perscription drugs can lead to optic neuropathy. These include:

• Arrhythmia medications

• Methanol

• Ethambutol

• Tobacco + alcohol

Vitamin deficiencies: Low B vitamin levels, especially vitamin B12, can lead to nerve damage.

Type 2 diabetes: The risk of optic nerve damage increases as diabetes becomes more advanced and blood sugar levels rise.

Optic neuropathy does not occur at the same rate for all parts of the population. There are several risk factors that put patients at a greater risk for the condition:

Sex: Women are more likely to develop optic neuropathy than men.

Age: Optic neuropathy is most likely to develop between the ages of 20 and 40.

Race: Caucasians are at a greater risk for optic neuropathy.

Location: People who live farther the equator have a slightly higher risk of developing optic neuropathy because they have less sun exposure and lower vitamin D levels.

Genes and mutations: Optic neuropathy and multiple sclerosis are both linked to certain genetic mutations.

Signs of optic neuropathy are typically first detected in an eye exam. This makes it crucial for patients to receive regular comprehensive eye exams.

The exam will typically start with the doctor asking questions about the patient’s medical history, symptoms they are experiencing, and other health conditions they have. Next, the doctor will conduct a number of procedures to test the patient's visual acuity, observe their ability to detect color, and measure their peripheral vision.

Doctors may also perform an ophthalmoscopy exam where they shine a light into the patient's eye to monitor activity in the back of the eye. This exam is used to evaluate a patient’s optic disk—the place where the optic nerve enters the retina. If this area is swollen, patients are more likely to develop optic neuropathy.

In some cases a patient’s doctor may also perform a pupillary light reaction test to see how their pupils respond to light. A patient's pupils won’t restrict as much when they have optic neuropathy.

If the doctor sees optic neuropathy symptoms they may conduct more advanced testing. This can include a magnetic resonance imaging (MRI) scan. This type of test uses magnetic fields to get more detailed pictures of a patient’s body.

The MRI scan is used to determine a patient's risk of developing multiple sclerosis—which is commonly linked to optic neuropathy. During the scan the doctor will look for lesions in the brain, which can show that the patient is at risk.

Other advanced tests a doctor may perform include blood tests, visual field tests, and an optical coherence tomography (OCT) which measures the thickness of the eye's retinal nerve fiber layer.

In most cases, optic neuropathy improves on its own. Doctors may prescribe anti-inflammatory or steroid medications to reduce inflammation, reduce pain, and prevent vision loss.

These types of treatments can be administered intravenously (in the vein) or orally where a patient will take high-dose steroids and gradually switch to a lower dose.

Eye doctors will also encourage patients to treat underlying causes and conditions that lead to optic neuropathy, the most common of which is multiple sclerosis. If a patient has or is showing signs of MS, a doctor may prescribe them multiple sclerosis medications.

While it is not possible to completely prevent optic neuropathy, there are a number of things that patients can do to reduce their risk of suffering from the condition:

• Avoid alcohol and tobacco products linked to optic neuropathy

• Manage autoimmune disorders and get quick treatment for infections

• Only use prescription medications recommended by their doctor

• Take steps to avoid vitamin deficiencies

• Get regular eye exams for a swift diagnosis and early treatment

Related: What Diseases Can Be Detected In An Eye Exam?

Patients' experience with optic neuropathy will depend on which type of condition they have and factors like their health and family history. Many patients will improve gradually without treatment and can expect not to experience much disruption.

Other patients may need to take additional corticosteroids medications prescribed by their doctor or other drugs to treat autoimmune conditions that may affect their optic neuropathy.

In both cases patients can expect to regain their normal vision. However, patients who have had an episode of optic neuropathy are at a greater risk of developing MS and other autoimmune disorders.

The best course for a swift and healthy recovery is for patients to see their eye doctor as soon as they notice symptoms. Following an episode patients should make an extra effort to schedule regular eye exams to treat and manage symptoms, should they return.