Optic Neuritis: Types, Causes, Symptoms, Diagnosis, and Treatment

Published on June 18th, 2024

Updated on December 15th, 2024

Optic neuritis is an eye condition that leads to eye pain and vision loss and occurs when the optic nerve is inflamed and swollen. Optic neuritis can result in eye pain and loss of vision due to inflammation impairing the signals that are transmitted through the optic nerve. The optic nerve consists of cells that are a fatty coating known as a myelin sheath according to the Cleveland Clinic. Developing optic neuritis can result in the deterioration of the sheath, therefore, leaving the optic nerve unprotected and unable to send signals properly. Inflammation typically causes a swollen optic nerve and in certain cases may result in optic nerve damage, inducing various forms of vision loss.

What is Optic Neuritis?

Optic neuritis is an eye condition that develops when the optic nerve is inflamed and swollen causing pain in the eye and in some cases vision loss or impaired vision. Optic neuritis can arise from potential causes such as autoimmune and inflammatory conditions and infections. This eye disease may also be known as nerve inflammation in the eye as the term neuritis is defined as inflammation of one or more nerves according to Brittanica. The three main types of this condition include typical, atypical and paediatric.

What Part of the Eye Does Optic Neuritis Affect?

Optic neuritis affects the optic nerve and can lead to optic nerve damage depending on the severity of your condition. The optic nerve is located at the back of each eye and connects directly to your brain to carry signals from your eyes to your brain. This is why optic nerve damage can severely affect your vision either short-term or long-term.

Graphic exhibiting the inside of the eye, revealing the optic nerve and how it connects from the eyes to the brain.

Are Optic Neuritis and Optic Neuropathy the same?

No, optic neuropathy is not the same as optic neuritis. Optic neuropathy is when the optic nerve is damaged whereas optic neuropathy is when the optic nerve is inflamed. Optic neuritis and optic neuropathy can both lead to varying degrees of vision loss as a result of their impact on the fibres that makeup the optic nerve. Optic neuropathy can bring on symptoms of eye pain, blind spots, poor colour vision or loss of vision according to the Lions Eye Institute.

Is Optic Neuritis a Common Eye Disease?

No, optic neuritis is not considered a common eye disease. Optic neuritis has an incidence rate of 0.56 and 5.1 cases per 100,000 according to Guier and Stokkermans (2023) in the National Library of Medicine. Reported occurrences of optic neuritis appeared more in women than in men. Acute optic neuritis was seen to affect young adults 20-45 years and atypical optic neuritis affected elderly patients more according to Medscape. Eye diseases are considered rare when it affects less than 200,000 people according to the National Institutes of Health.

What are the Main Types of Optic Neuritis?

The main types of optic neuritis are typical, atypical and paediatric. It is important to note that while there are different types of optic neuritis, they all share the same symptoms of eye pain and vision impairment and all stem from possible causes such as autoimmune diseases and infections. The main types of optic neuritis are listed below.

Typical: Typical optic neuritis is a type that may only affect one eye and is known to have a good prognosis.
Atypical: Atypical optic neuritis typically affects both eyes and patients with it may not recover as quickly. Symptoms of atypical optic neuritis can include visual acuity and visual field loss and impaired light perception.
Paediatric: Paediatric optic neuritis is the form that occurs during childhood and is similar to typical and atypical. However, this type may have a better outcome in recovery.

1. Typical

Typical optic neuritis is the form that only affects one eye and is commonly associated with multiple sclerosis. Typical optic neuritis can often stem from autoimmune, infectious or inflammatory disorders. While eye pain is prevalent in all three types, typical optic neuritis presents pain that is worse with eye movement. Typical optic neuritis has predominantly affected females and the age range of 20-40 years old according to Bhatti (2023) in the National Library of Medicine.

2. Atypical

Atypical optic neuritis is the type that affects both eyes and can either lead to persistent eye pain or may occur without pain. Atypical optic neuritis has mainly affected males and can be caused by a diverse collection of disorders according to Bhatti (2023) in the National Library of Medicine. Unlike typical optic neuritis, atypical optic neuritis does not typically have an optimal visual recovery rate.

3. Paediatric

Paediatric optic neuritis is the childhood form of optic neuritis and just like the typical optic neuritis, causes pain during eye movement and may likely stem from autoimmune disorders or infections. Paediatric optic neuritis is typically diagnosed with a standard eye test, which examines different regions and functions of the eye. Paediatric optic neuritis overall presents a good prognosis with cases responding well to treatment and does not lead to long-term vision problems or pain in the eye.

What are the Symptoms of Optic Neuritis?

The symptoms of optic neuritis are eye pain, vision loss and flashing lights. The symptoms of optic neuritis are listed below.

Eye Pain: Eye pain is a symptom of optic neuritis and occurs during eye movement. Eye pain caused by optic neuritis is typically felt around the eyeballs.
Vision Loss: Vision loss refers to the partial or complete loss of vision and can include experiencing blind spots, difficulty seeing details and the sharpness of objects.
Flashing Lights: Flashing lights can appear in your vision during optic neuritis as a result of the inflammation in the optic nerve.

1. Eye Pain

Eye pain can develop when you have optic neuritis and may be the first sign of this condition. Eye pain caused by optic neuritis can feel more intense when moving your eyes especially if you develop typical optic neuritis. The eye pain from optic neuritis may feel like a dull pain around your eyeballs and can vary in duration and intensity depending on what type of optic neuritis you have.

2. Vision Loss

Vision loss can ensue as a result of optic neuritis and can include loss of both your colour vision and visual fields. Vision loss can occur in varying forms due to the inflammation in the optic nerve, hindering its proper transmission of signals to the brain. This causes blind spots in your vision, the inability to see fine details of objects and difficulty seeing or differentiating between certain colours. Vision loss may occur temporarily or long-term depending on what type of optic neuritis you have. It is important to see an optometrist right away if you are experiencing vision loss as untreated optic neuritis may lead to permanent blindness.

3. Flashing Lights

Flashing lights are a form of visual disturbance that can appear in your vision when developing optic neuritis and can be described as lightning streaks or sparkles in your peripheral vision. Flashing lights are generally not harmful but may be unpleasant or unsettling for patients. Therefore, it is important to see an optometrist who will then refer you to an ophthalmologist. Addressing the cause of inflammation may help stop the flashing lights.

Man holding his finger over his painful eye, pain is indicated by a red spot over the affected eye.

Can Eyeglasses Help Eye Muscle Problems?

Yes and no, eyeglasses may be able to help with eye muscle problems that affect your vision. Corrective eyeglasses may be helpful for eye muscle problems such as mild cases of crossed eye (strabismus), lazy eye (amblyopia) and nystagmus. However, it is important to note that eyeglasses may not be helpful in correcting the condition but instead may improve your vision when wearing them.

What are the Causes of Optic Neuritis?

The causes of optic neuritis are infections, drugs and toxins, autoimmune and inflammatory conditions, lack of blood flow and nerve compression. However, research notes that the exact cause of optic neuritis is yet to be definitively identified according to Guier and Stokkermans (2023) in the National Library of Medicine. The causes of optic neuritis are listed below.

Infections: Infections caused by bacteria, viruses, fungi and parasites are often reported to be involved in the cause of optic neuritis.
Drugs and Toxins: Certain drugs and toxins have been reported to be associated with the development of optic neuritis.
Autoimmune and Inflammatory Conditions: Autoimmune and inflammatory conditions such as multiple sclerosis, neuromyelitis optica and myelin oligodendrocyte glycoprotein (MOG) antibody disorder are known to be other causes of optic neuritis.
Lack of Blood Flow: A Lack of blood flow to the optic nerve can cause its cells to malfunction, which can cause inflammation.
Nerve Compression: Nerve compression from tumours or a build-up of fluid can lead to inflammation and damage of the optic nerve.

1. Infections

Infections can contribute as a possible cause of optic neuritis due to their potential impact on the nerves of the body including the optic nerve. Infections that can lead to the development of optic neuritis may include viral, bacterial, fungal and parasitic infections. Common viruses that can cause optic neuritis include herpes simplex 1 and 2 varicella-zoster cytomegalovirus according to the Guier and Stokkermans (2023). Possible examples of bacteria that can result in optic neuritis include bartonella henselae (Cat-scratch disease), treponema pallidum (syphilis) borrelia burgdorferi (lyme disease) and mycobacterium tuberculosis (tuberculosis). Fungal infections may include cryptococcus, histoplasmosis, aspergillus and mucormycosis. Parasitic infections that can result in optic neuritis can be caused by toxoplasmosis, toxocariasis and diffuse unilateral subacute necrosis (DUSN).

2. Drugs and Toxins

Drugs and toxins are possible causes of optic neuritis and can include both prescribed drugs to treat other conditions and non-prescribed drugs. Drugs and toxins such as ethambutol, methanol commonly found in antifreeze, solvent and paints, chloramphenicol, isoniazid or sulfa-type antibiotics, arrhythmia medications and malaria medications are possible causes that lead to optic neuritis according to the National Library of Medicine.

3. Autoimmune and Inflammatory Conditions

Autoimmune and inflammatory conditions may be a likely cause or risk factor for optic neuritis. Autoimmune and inflammatory conditions such as multiple sclerosis, neuromyelitis optica (NMO) and myelin oligodendrocyte glycoprotein (MOG) antibody disorder (MOGAD) are probable factors for developing optic neuritis due to their effect on the optic nerve. According to the Cleveland Clinic, optic neuritis is typically the first sign a patient has multiple sclerosis while neuromyelitis optica and MOG-antibody-associated disease are often linked with atypical optic neuritis. Although the exact cause of optic neuritis is not known, it is proposed that the autoimmune response harms the protective sheath around the optic nerve according to the National Library of Medicine.

4. Lack of Blood Flow

The lack of blood flow to the optic nerve can harm its cells, stopping them from working properly and leading to optic nerve inflammation and damage. The optic nerve requires nutrients and oxygen through optimal blood supply. Therefore, when blood flow to the optic nerve is disrupted, often due to certain conditions, this inflammation disrupts the transmission of visual signals to the brain.

5. Nerve Compression

Nerve compression can result in optic neuritis due to the pressure on the optic nerve, preventing its function and therefore triggering inflammation. Nerve compression can take place due to surrounding structures, such as enlarged blood vessels, tumours, or inflamed tissues, pushing against the optic nerve. Treating the initial cause of what may be pressing on the optic nerve may help bring down the compression.

How do Eye Doctors Diagnose Optic Neuritis?

Eye doctors can diagnose optic neuritis by conducting an eye exam. An ophthalmologist and optometrist can check your optic nerve for inflammation by shining a light into your eyes with a slit lamp. However, you will need to see an optometrist for your eye test first so they can look at all the different parts of your eye. This will help the optometrist refer you to an ophthalmologist for further evaluation of your condition.

What are the Eye Tests for Diagnosing Optic Neuritis?

The eye tests for diagnosing optic neuritis can include a visual acuity test, visual field test, pupillary reactions test and a slit lamp exam. Eye tests are vital for maintaining eye and vision health and in helping identify signs of eye problems and diseases. The eye tests for diagnosing optic neuritis are listed below.

Visual Acuity Test: A visual acuity test measures the sharpness and clarity of a person’s vision and is performed by an optometrist as part of a standard eye test. A visual acuity test uses a letter chart and the results of the test will be read as a fraction or ratio.
Visual Field Test: A visual field test (VFT) is used to quantify how well a person can see peripherally through each eye individually. A visual field test helps the optometrist establish a baseline of vision and diagnose ocular injuries or diseases, including glaucoma.
Pupillary Reactions Test: Pupillary reactions for eyes, refers to how the pupil of the eye responds to light stimuli. The pupillary light reflex is an important part of eye health as it is used to assess optic nerve function.
Slit Lamp Exam: A slit lamp exam is a type of eye test performed by an optometrist or other eye care professionals to examine the inside of a patient’s eye.

1. Visual Acuity Test

A visual acuity test is a common eye test performed by an optometrist as part of a comprehensive eye test to diagnose a range of eye conditions including optic neuritis. A visual acuity test examines a person’s visual acuity which is the measure of the sharpness and clarity of vision, which can assist with identifying signs of optic neuritis. This test is performed using an eye chart, most commonly a Snellen chart. Visual acuity is tested one eye at a time to measure the visual acuity individually and then tested with both eyes uncovered.

2. Visual Field Test

Visual field testing is a non-invasive examination that is useful in the diagnosis and monitoring of conditions such as glaucoma as well as neurological conditions like optic neuritis. A visual field test is performed to quantify how well a person can see peripherally with each eye individually. It is most often performed using a visual field machine which is a specialised piece of equipment that records how well each eye can see, and based on the results can reveal links to neurological conditions such as optic neuritis.

3. Pupillary Reactions Test

A pupillary reaction test assesses how well the pupil functions, and their response to light stimuli. During a pupillary reactions test, a light is shone into one eye, causing the pupil to become smaller as a result of the pupillary light reflex, which is a natural response of the eye. This test evaluates the health of the optic nerve and can identify any abnormalities in the pupillary reactions that can indicate optic nerve damage, inflammation and other major concerns.

4. Slit Lamp Exam

A slit lamp test is used to check for signs of eye diseases and abnormalities as well as check the overall health of the eye, including the optic nerve. A slit-lamp exam is a procedure performed in a standard eye test that assists optometrists in examining all parts of the eye and further inside the eye using a machine. Before a slit-lamp examination, the optometrist may need to dilate a patient's pupils to get a better look at the back of the eye, which can reveal any signs of optic neuritis.

Graphic of boy standing in front of lettered chart for visual acuity test.

What are the Treatments for Optic Neuritis?

The treatments for optic neuritis may include intravenous (IV) drugs (steroids) or treating the initial causes. Treating optic neuritis with IV steroids may be helpful in alleviating the inflammation, and preventing further damage to the optic nerve. Addressing the initial causes or contributing factors may include treating bacterial infections with antibiotics.

What Might Happen if Optic Neuritis is Left Untreated?

If optic neuritis is left untreated, the optic nerve may be permanently damaged. Optic neuritis should be treated right away to prevent further vision complications. If you are experiencing any changes to your vision, it is important to see an optometrist right away so the eye care professional can begin the necessary treatment.

Can Optic Neuritis be Treated at Home?

No, optic neuritis cannot be treated at home. Optic neuritis involves inflammation of the optic nerve and therefore will require management and treatment provided by an ophthalmologist, who specialises in these types of eye conditions. It is important to always consult a health care professional first before attempting any treatments on yourself.

Do You Need Eye Surgery to Treat Optic Neuritis?

No, you don’t need eye surgery to treat optic neuritis as inflammation is generally treated with medication. Optic neuritis does not qualify for eye surgery and does not always require medical treatment as some cases can recover without medical intervention according to Better Health.

Can Optic Neuritis be Treated Permanently?

No, optic neuritis may not be treated permanently. Optic neuritis usually occurs as a result of an underlying condition and therefore can recur depending on the severity and nature of the initial cause. Optic neuritis can alleviate on its own after a few weeks or months. Treatment may aid with faster recovery from inflammation, however, treatment may not affect the amount of vision you recover according to Healthdirect.

What are the Complications of Optic Neuritis?

The complications of optic neuritis are primarily vision loss and/or impaired vision. Patients with optic neuritis can develop loss of vision to different degrees depending on how severe your condition is. Vision loss and impaired vision complications can include poor visual acuity, visual field loss or colour vision loss. However, these complications are often temporary and can return back to normal after some time.

Can Optic Neuritis Cause Eye Pain When Blinking?

Yes, optic neuritis can cause eye pain when blinking as a consequence of the inflammation. Patients with optic neuritis often experience ocular pain during eye movement and can range in severity depending on which type you have. If you’re experiencing eye pain when blinking, it is important to see an optometrist or your local doctor.

Can Optic Neuritis Cause Papilledema?

Yes, optic neuritis can cause papilledema. Optic neuritis is one of the many etiologies that can lead to papilledema according to Nguyen, Haider and Ackerman (2013) in the National Library of Medicine. Papilledema is defined as the swelling of the optic disc, which can be caused by an increase in intracranial pressure. The optic disc refers to the structure around the end of the optic nerve that connects this nerve to the retina.

How to Prevent Optic Neuritis?

You may be able to prevent optic neuritis by managing underlying conditions that may lead to the development of optic neuritis such as multiple sclerosis (MS). Preventing optic neuritis may also include maintaining a healthy lifestyle, which includes regular exercise and eating a balanced diet, which can support your overall health. Additionally, staying on top of your regular eye tests can help detect early signs of optic neuritis, enabling timely medical intervention and management.

Can Eyeglasses Help Prevent Optic Neuritis?

No, eyeglasses do not help prevent optic neuritis as it affects the optic nerve and not the other structures of the eyes that contribute to refractive errors. Eyeglasses are likely not effective in the prevention of optic neuritis as they are designed to correct refractive errors which are vision problems caused by either an abnormally shaped lens or cornea.

How Long Does Optic Neuritis Last?

Optic neuritis may last around 4-12 weeks. According to Better Health, optic neuritis may improve even without the use of medication roughly after a couple of weeks as the inflammation subsides. However, this can differ between individuals according to the extent of their condition. Your eye care specialist will be able to let you know what you can expect of your condition during your appointment.

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