Noninfective chorioretinitis is an eye condition where the choroid and retina at the back of your eye become inflamed without an infectious cause. This inflammation can threaten your vision and requires prompt medical attention. Understanding the noninfectious triggers, recognizing symptoms early, and seeking appropriate treatment can help protect your eyesight from permanent damage.

Understanding Noninfective Chorioretinitis

Noninfective chorioretinitis is a type of posterior uveitis, which means inflammation affecting the back portions of the eye. The term “uveitis” refers to inflammation of the uveal tract, which includes the iris, ciliary body, and choroid. However, this inflammation can also affect nearby structures such as the retina, retinal blood vessels, the vitreous (the clear gel filling the eye), the optic nerve head, and the sclera (the white outer layer of the eye).^[1]

The choroid is a crucial vascular layer of the eye that sits between the retina and the sclera. It functions as the blood supply system for the outer layers of the retina, delivering oxygen and nutrients that are essential for vision. When the choroid and retina become inflamed together, this creates chorioretinitis. The inflammation can be classified based on where it occurs in the eye, how it appears, and how it develops over time—whether suddenly or gradually, as a single episode or recurring.^[1]

Because the choroid provides vital nourishment to the retina, inflammation in these layers can lead to serious vision-threatening complications. The condition can affect people at any age and may be associated with various systemic diseases or occur without any identifiable systemic connection.^[2]

Epidemiology: How Common Is Noninfective Chorioretinitis?

Uveitis, the broader category that includes noninfective chorioretinitis, affects between 52 and 341 people per 100,000 person-years in the United States. This means that each year, for every 100,000 people, somewhere between 52 and 341 new cases are diagnosed. The variation in these numbers reflects differences in study populations and geographic regions.^[1]

This condition is responsible for a significant portion of vision loss in the United States. Studies have shown that uveitis contributes to between 2.8% and 10% of all blindness cases in the country. Each year, approximately 30,000 new cases of legal blindness result from uveitis, accounting for 10% to 15% of all cases of total blindness in the nation.^[5]

The occurrence of uveitis, including noninfective chorioretinitis, tends to increase with age. Women, particularly those in their childbearing years, appear to be more susceptible to eye inflammatory conditions than men. This gender difference suggests that hormonal factors may play a role in the development of these conditions.^[5]

Causes of Noninfective Chorioretinitis

Unlike infectious chorioretinitis, which results from bacteria, viruses, parasites, or fungi, noninfective chorioretinitis develops without any infectious agent. The causes can be broadly divided into those associated with systemic diseases and those that occur without any systemic connection.^[1]

When noninfective chorioretinitis is associated with systemic diseases, two conditions are particularly notable. Sarcoidosis is a disease characterized by inflammation in various body tissues, and when it affects the eyes, it can cause chorioretinitis. Behçet’s disease is another systemic condition that causes blood vessel inflammation throughout the body, including the eyes.^[1]

In addition to these systemic causes, noninfective chorioretinitis can be triggered by autoimmune and inflammatory illnesses. Conditions such as rheumatoid arthritis, where the immune system attacks the body’s own joints and tissues, can also affect the eyes. The immune system’s misdirected attack can lead to inflammation of the choroid and retina.^[2]

Several specific eye conditions fall under the category of noninfective chorioretinitis without systemic associations. These include multifocal choroiditis with panuveitis, punctate inner choroidopathy, multiple evanescent white dots syndrome, unilateral acute idiopathic maculopathy, birdshot choroidopathy, and serpiginous choroidopathy. Each of these conditions has distinct characteristics but all involve inflammation of the choroid and retina without an infectious cause.^[1]

Other causes of noninfective chorioretinitis include malignancies such as lymphoma, which can masquerade as uveitis. Cancer-associated retinopathy is another possibility. Eye injuries or trauma can also trigger inflammation of the choroid and retina. In some instances, conditions like sympathetic ophthalmia and Vogt Koyanagi Harada syndrome involve choroidal inflammation as part of a more widespread inflammation throughout the eye.^[1]

Some genetic conditions may predispose individuals to developing noninfective chorioretinitis. For example, birdshot choroidopathy is strongly associated with a specific genetic marker called HLA-A29.^[2]

Risk Factors for Developing Noninfective Chorioretinitis

Several factors can increase a person’s risk of developing noninfective chorioretinitis. Having an autoimmune disease is one of the most significant risk factors. Conditions such as rheumatoid arthritis, sarcoidosis, and Behçet’s disease all involve the immune system attacking the body’s own tissues, and this immune dysfunction can extend to the eyes.^[2]

A history of eye injury or trauma increases the risk of developing chorioretinitis. Physical damage to the eye can trigger an inflammatory response that, in some cases, becomes chronic or recurrent. This inflammation can affect both the injured eye and, in rare cases of sympathetic ophthalmia, even the uninjured eye.^[2]

Age is another factor that influences risk. As mentioned in the epidemiology section, the occurrence of uveitis increases with age. This may be related to cumulative environmental exposures, changes in immune system function, or the development of other age-related health conditions.^[5]

Gender appears to play a role as well. Women, particularly during their childbearing years, are more likely to develop eye inflammatory conditions compared to men. This pattern suggests that hormonal influences may affect susceptibility to these conditions.^[5]

Genetic factors can also increase risk. Certain genetic markers, such as the HLA-A29 gene, are strongly associated with specific types of noninfective chorioretinitis like birdshot choroidopathy. People with these genetic markers have a higher likelihood of developing certain forms of the condition.^[2]

Having one or more autoimmune or inflammatory diseases that are not properly monitored or controlled can increase the risk of developing eye complications, including chorioretinitis. This is why individuals with systemic autoimmune conditions should have regular eye examinations.^[7]

Symptoms of Noninfective Chorioretinitis

The symptoms of noninfective chorioretinitis can vary in severity depending on the extent and location of the inflammation. One of the most common symptoms is blurred vision, which may develop gradually or appear suddenly. This blurring occurs because inflammation in the choroid and retina disrupts the normal processing of visual information.^[2]

Many people with chorioretinitis notice black spots or floaters in their vision. These appear as dark specks, strings, or cobweb-like shapes that seem to drift across the field of view. Floaters occur when inflammatory cells or debris cast shadows on the retina. Some people also experience flashes of light, which result from the retina being stimulated by the inflammatory process.^[2]

Eye pain is another common symptom. The discomfort may be dull or sharp and can worsen when moving the eyes. The affected eye may also appear red due to inflammation of blood vessels on the eye’s surface.^[2]

Photophobia, or sensitivity to light, is frequently reported by people with chorioretinitis. Bright lights may cause discomfort or pain, making it difficult to be in well-lit environments or outdoors on sunny days. This sensitivity occurs because inflammation increases the eye’s reactivity to light.^[2]

Excessive tearing or watering of the eye can occur as the eye attempts to soothe itself in response to irritation and inflammation. Some people also notice difficulty seeing colors accurately, as inflammation can affect the retina’s ability to distinguish different wavelengths of light. Night vision may also be impaired, making it harder to see in low-light conditions.^[7]

In some cases, people experience distortion of objects, where straight lines appear wavy or bent. Progressive loss of vision can occur if the inflammation is not treated, and some people may notice a narrowing of their peripheral vision, as though they are looking through a tunnel.^[7]

Prevention Strategies

While not all cases of noninfective chorioretinitis can be prevented, several strategies may reduce the risk or severity of the condition. Regular eye examinations are crucial, especially for people with autoimmune diseases or other risk factors. Early detection allows for prompt treatment, which can prevent complications and preserve vision.^[7]

For individuals with autoimmune or inflammatory diseases, proper management and treatment of the underlying condition is essential. Working closely with healthcare providers to control conditions like rheumatoid arthritis, sarcoidosis, or Behçet’s disease can help reduce the risk of eye complications. Taking prescribed medications consistently and attending regular follow-up appointments are important steps.^[7]

Protecting the eyes from injury is another important preventive measure. Wearing appropriate eye protection during activities that pose a risk of eye trauma, such as sports, construction work, or activities involving flying debris, can help prevent injury-related chorioretinitis.^[2]

Being aware of family history and genetic risk factors can also be valuable. If you have a family member with certain types of noninfective chorioretinitis or if you know you carry genetic markers associated with these conditions, discuss this information with your eye care provider. They may recommend more frequent monitoring or preventive measures.^[2]

Promptly addressing any eye symptoms is critical. If you experience any signs of chorioretinitis, such as blurred vision, floaters, flashes of light, or eye pain, contact an eye care professional immediately. Early intervention can make a significant difference in preserving vision and preventing long-term complications.^[7]

How Noninfective Chorioretinitis Affects the Body (Pathophysiology)

To understand how noninfective chorioretinitis affects the eye, it’s helpful to understand the normal structure and function of the affected areas. The uveal tract consists of three parts: the iris (the colored part of the eye), the ciliary body (which produces fluid and helps the lens focus), and the choroid (the vascular layer that nourishes the retina). The choroid contains numerous blood vessels and is located between the retina and the sclera.^[3]

In noninfective chorioretinitis, the inflammatory process begins without an infectious trigger. Instead, it may be initiated by autoimmune processes, where the body’s immune system mistakenly identifies components of the choroid and retina as foreign and attacks them. This immune response involves various cells and inflammatory molecules that cause tissue damage and swelling.^[9]

When inflammation develops in the choroid, it disrupts the normal blood supply to the outer layers of the retina. The retina is a delicate, light-sensitive tissue that requires constant nourishment from the choroidal blood vessels. When these vessels become inflamed, blood flow may be reduced or altered, depriving retinal cells of oxygen and nutrients. This can lead to retinal cell damage and death.^[1]

The inflammation itself causes physical and biochemical changes in the eye tissues. Inflammatory cells infiltrate the choroid and retina, releasing chemicals that increase blood vessel permeability. This allows fluid to leak from vessels into surrounding tissues, causing swelling or edema. The swelling can distort the normal architecture of the retina, affecting its ability to process visual information accurately.^[9]

As the inflammatory process continues, it can affect the vitreous, the clear gel that fills the space between the lens and the retina. Inflammatory cells and debris can accumulate in the vitreous, creating the floaters that many people with chorioretinitis experience. The inflammation can also involve the retinal blood vessels, causing vasculitis, or inflammation of the vessel walls.^[1]

Over time, chronic inflammation can lead to scarring of the choroid and retina. When scarred tissue forms, it is no longer functional and cannot contribute to vision. These scars, called chorioretinal scars, appear as areas of tissue loss or color changes at the back of the eye. If scarring occurs in critical areas like the macula (the central part of the retina responsible for detailed vision), it can cause permanent vision loss.^[2]

In severe cases, the inflammation can extend to involve the optic nerve head, where the optic nerve connects to the eye. This can affect the transmission of visual signals from the eye to the brain. The inflammatory process can also trigger changes in intraocular pressure, potentially leading to secondary complications like glaucoma.^[1]

The mechanisms behind different types of noninfective chorioretinitis vary. In conditions associated with systemic autoimmune diseases, the same immune dysfunction affecting other body parts also targets eye tissues. In idiopathic cases (where no cause is identified), the immune system may be reacting to unknown triggers or there may be a genetic predisposition to ocular inflammation.^[1]

Some forms of noninfective chorioretinitis, such as serpiginous choroidopathy, are particularly aggressive and can cause extensive damage to the choriocapillaris (the layer of tiny blood vessels in the choroid). This type results in large areas of chorioretinal scarring if not treated promptly and aggressively. Other forms, like birdshot choroidopathy, tend to cause more diffuse inflammation with multiple small spots of involvement throughout the choroid.^[11]

The body’s attempt to heal the inflammation can sometimes cause additional problems. As healing occurs, new blood vessels may grow abnormally, a process called neovascularization. These new vessels are often fragile and can leak or bleed, causing further vision problems. The formation of scar tissue during healing can also cause traction on the retina, potentially leading to retinal detachment.^[9]