Autoimmune Uveitis

Autoimmune uveitis is an inflammatory eye condition that can threaten your vision if not properly diagnosed and treated. This disease occurs when your body’s immune system mistakenly attacks healthy tissue inside your eye, causing swelling and potentially serious complications.

Table of contents

• What Is Autoimmune Uveitis?
• The Uvea and Eye Anatomy
• Types of Autoimmune Uveitis
• Signs and Symptoms
• What Causes Autoimmune Uveitis?
• Autoimmune Diseases Associated with Uveitis
• Risk Factors
• How Is Autoimmune Uveitis Diagnosed?
• Treatment Options
• Possible Complications

What Is Autoimmune Uveitis?

Autoimmune uveitis is an inflammatory process that affects the uveal components of your eye due to an autoimmune reaction to self-antigens or caused by an innate inflammatory reaction secondary to an external stimulus^[1]. In simpler terms, this means your immune system becomes hyperactive or malfunctions, causing it to attack the uvea in your eyes because it mistakes it to be a foreign object or threat^[8].

This condition can present as an isolated entity or be associated with a systemic autoimmune or autoinflammatory disease (a condition where the body’s immune system causes inflammation without a clear reason)^[1]. Though the condition is rare, it ranks as the fourth most prevalent cause of blindness among young individuals in developed countries^[8]. Roughly 30,000 new cases of legal blindness are thought to arise from uveitis annually in the United States^[8].

The Uvea and Eye Anatomy

• Iris
• Ciliary body
• Choroid
• Retina
• Vitreous body
• Optic nerve

The uvea represents the vascular organ of the eye and is composed of the iris, ciliary body, and choroid^[1]. The uvea is the middle layer of the eye between the sclera (white part of the eye) and the retina (light-sensitive layer at the back of the eye)^[2].

The iris is the colored part of your eye that controls pupil size and light admission. The ciliary body is located behind the iris and helps the lens focus. The choroid is a layer of blood vessels between the retina and the sclera that delivers blood to the back of the eye and nourishes the outer layers of the retina with oxygenated blood^[6].

Because of its proximity to other parts in the eye, inflammation can cause damage to ocular layers such as the retina and structures like the vitreous body and optic nerve^[1]. There isn’t a lot of room inside your eyeball for tissue swelling to happen, so it’s easy for swelling to change your eye shape. Your eye shape is a critical part of how you see, and even tiny changes from swelling can disrupt your sight^[7].

Types of Autoimmune Uveitis

Uveitis is categorized by which portions of the eye are inflamed rather than the degree of severity. The type of uveitis you have depends on which part or parts of the eye are affected^[9].

Anterior uveitis affects the inside of the front of the eye, particularly the iris and ciliary body. It is the most common type and is often referred to as “iritis” because it affects the iris. This type is usually less serious and may manifest as iritis (affecting the iris) or iridocyclitis (affecting the ciliary body as well)^[1][2].

Intermediate uveitis affects the middle portion of the eye, including the vitreous cavity and may involve the pars plana. This type can cause floaters and blurred vision and impacts your peripheral retina, the tissue layer crucial for side and night vision^[6][8].

Posterior uveitis affects the back portion of the eye, including the retina and the choroid. This type is divided into three types: choroiditis, retinochoroiditis, and chorioretinitis^[1]. Though posterior uveitis is the least common, it is more serious than anterior uveitis because it causes scarring to the retina and can lead to vision loss^[8].

Panuveitis is inflammation throughout the eye, affecting all three areas from the front to the back of the eye. People with panuveitis show a combination of symptoms of the three other types of uveitis^[8].

Signs and Symptoms

Common symptoms of uveitis are blurred vision, photophobia (eye sensitivity to bright light), eye pain, floaters (floating spots or squiggly lines that float across your vision), headache and injected conjunctiva^[1][2]. The symptoms of uveitis can vary depending on which area of your eye it affects.

The symptoms often start suddenly and may include:

• Eye redness
• Eye pain
• Light sensitivity
• Blurred vision
• Dark, floating spots in your field of vision (floaters)
• Decreased vision
• Swelling, redness, and pain in the eye
• Bloodshot eyes

These symptoms can develop suddenly or gradually in one or both eyes over a few days^[8]. Usually in children, the condition can be asymptomatic (without noticeable symptoms)^[1]. If you notice any of these symptoms, see your eye doctor right away because uveitis can cause vision loss if you don’t treat it^[2].

What Causes Autoimmune Uveitis?

Autoimmune uveitis is an inflammatory process of the uveal components due to an autoimmune reaction to self-antigens or caused by an innate inflammatory reaction secondary to an external stimulus^[1]. In autoimmune uveitis, your immune system becomes hyperactive or malfunctions, causing it to attack the uvea in your eyes because it mistakes it to be a foreign object or threat to you^[8].

This response causes the release of specific inflammatory mediators (molecules) that cause inflammation within the eye. Inflammation can also affect other areas of your eye^[8]. Between 50% and 70% of uveitis cases are idiopathic, meaning the cause isn’t something an eye care specialist can see or test for^[7].

Sometimes uveitis means your immune system is fighting an eye infection, but it can also happen when your immune system attacks healthy tissue in your eyes^[2]. While the response’s reason is yet unknown, it may manifest in people with a genetic predisposition due to such triggers as bacteria, viruses, toxins, hormones, and some drugs^[6].

Autoimmune Diseases Associated with Uveitis

There is a strong correlation between uveitis and underlying autoimmune illnesses^[6]. Eye inflammation can be the initial presentation in many autoimmune diseases manifesting as conjunctivitis, episcleritis, or scleritis^[1]. Sometimes uveitis is caused by autoimmune diseases like:

• Ankylosing spondylitis
• Behçet’s disease
• Lupus (systemic lupus erythematosus)
• Multiple sclerosis
• Psoriasis
• Rheumatoid arthritis
• Sarcoidosis
• Ulcerative colitis
• Vogt-Koyanagi-Harada disease
• AIDS (acquired immunodeficiency syndrome)
• Juvenile idiopathic arthritis
• Psoriatic arthritis
• Vasculitis

Diseases such as rheumatoid arthritis and systemic lupus erythematosus are commonly associated with these types of manifestations. On the other hand, anterior uveitis typically appears as the initial manifestation in autoinflammatory diseases such as ankylosing spondylitis^[1]. There is a clear association described with the HLA-B27 positivity and a higher risk of presenting recurrent anterior uveitis in ankylosing spondylitis^[1].

Data from consecutive uveitis patients showed that 37.2% of all cases showed an association between uveitis and extra-organ diseases; diseases with primarily arthritic manifestations were seen in 10.1% of all cases, non-infectious systemic diseases (such as Behçet’s disease, sarcoidosis or multiple sclerosis) in 8.4%^[10].

Risk Factors

Anyone can get uveitis, but it’s most common in people ages 20 to 60. The mean age of uveitis patients at the onset of the disease is less than 40 years of age^[10]. You’re at higher risk for uveitis if you smoke cigarettes^[2].

You’re at higher risk if you have autoimmune diseases or immunodeficiency diseases. Uveitis is more common in adults, and the odds of having it go up with age. It’s less common in children, who make up only 2% to 20% of cases^[7].

How Is Autoimmune Uveitis Diagnosed?

The suspicion of uveitis requires a prompt referral to an ophthalmologist at the emergency room who is in charge of the uveitis pattern definition^[1]. Eye doctors can check for uveitis as part of a dilated eye exam (an examination where drops are used to widen your pupil so the doctor can see inside your eye). The exam is simple and painless — your doctor will give you some eye drops to dilate (widen) your pupil and then check your eyes for uveitis and other eye problems^[2].

When you visit an eye specialist, the specialist will likely do a complete eye exam and gather a thorough health history. The eye exam usually involves the following:

• Assessment of vision and the response of your pupils to light
• Tonometry (a test that measures the pressure inside your eye)
• A slit-lamp examination (a microscope that magnifies and illuminates the front of the eye)
• Ophthalmoscopy (examination of the back of the eye)

Your doctor will also ask about your medical history — and may recommend some tests to see if you have an infection or another disease that can cause uveitis^[2]. The eye specialist also may recommend:

• Color photography of the inside of the eye
• Optical coherence tomography (OCT) imaging (a test that maps the retina and choroid to reveal swelling)
• Fluorescein angiography or indocyanine green angiography
• Analysis of aqueous or vitreous fluid from the eye
• Blood tests
• Imaging tests, radiography, CT or MRI scans

In addition to review of systems and ocular exam, doctors do bloodwork to rule out infection and help identify signs of systemic autoimmune activity (such as HLA haplotyping, antinuclear antibodies, serum angiotensin-converting enzyme, lysozyme)^[13].

Treatment Options

Medicines called steroids (medications that reduce inflammation) can reduce inflammation in your eye. This can ease symptoms and prevent vision loss^[2]. The treatment of uveitis depends on the location of inflammation within the eye, the extent of inflammation, and the underlying cause^[5].

First line treatment often involves administration of steroid medications to help reduce inflammation, which may be given via eye drops or pills^[5]. Your eye doctor may prescribe steroids as eye drops, pills, or injections. Eye drops can serve as pain relievers, dilators to minimize motion, and anti-inflammatories to reduce swelling^[1].

In patients who don’t respond to steroids, numerous other immunosuppressive medications such as DMARDs (disease-modifying antirheumatic drugs) may be used. These medications may require close monitoring and frequent follow-up with a rheumatologist^[5].

Treatment may involve anti-inflammatory eye drops or oral medications. Additionally, corticosteroid eye drops can diminish redness, inflammation, discomfort, and pain. Your retina specialist may suggest steroid tablets, injections, immunosuppressive medications, or surgery based on your condition^[3].

Targeted biologic treatments for autoimmune disease have been approved in recent years, including some specifically for non-infectious uveitis^[13]. Treatment usually takes effect in a few days to a week, though inflammation may continue for months and even years in severe cases^[1].

Possible Complications

Uveitis can be serious, leading to permanent vision loss if not treated early^[4]. This compromise is considered one of the principal causes of preventable blindness around the world^[1]. If left untreated, uveitis can lead to vision loss^[2].

Patients over 60, those with long-term uveitis, and some who have uveitis in the middle or back of the eye might be at increased risk of complications. If left untreated, uveitis can cause long-term problems such as:

• Cataracts (clouding of the lens of the eye)
• Damage to the optic nerve that can lead to vision loss
• Detachment of the retina
• Glaucoma (when fluid can’t drain from the eye leading to increased pressure in the eye)
• Macular edema (swelling of the retina)
• Retina scarring in spots, which can lead to vision loss
• Permanent vision loss and blindness

Steroids can have side effects and can increase your risk for cataracts and glaucoma. If you take steroids for uveitis, regular eye exams are important to monitor your progress and to check for signs of any problems^[2][9].

Since autoimmune uveitis is the initial presentation of some autoimmune diseases, it is important that both ophthalmologists and rheumatologists work together to achieve a faster diagnosis and a more effective treatment for patients^[1]. Patients have a good chance of preserving their vision when uveitis is detected early^[3].