Chorioretinitis

Chorioretinitis is inflammation of the back part of your eye that can threaten your vision and even lead to blindness if not treated promptly.

Table of contents

• What is Chorioretinitis?
• Associated Anatomy
• Causes of Chorioretinitis
• Signs and Symptoms
• Diagnosis and Testing
• Treatment Options
• Complications
• Prevention

What is Chorioretinitis?

Chorioretinitis is a type of uveitis (inflammation of the eye). It specifically affects the back part of your eye, where inflammation occurs in both the choroid and the retina^[1].

The choroid is a layer of eye tissue filled with blood vessels. It sits between your retina and the white outer part of your eye. Your choroid has an important job because it provides nutrients and support to your retina, which is essential for vision^[1].

When these layers become inflamed, it creates a condition called chorioretinitis. This is classified as posterior uveitis, meaning it affects the back parts of your eye. The inflammation can be serious enough to cause vision loss if not treated^[2].

Sometimes the inflammation becomes severe enough to cause actual damage to the eye tissues. When this happens, doctors may call it chorioretinopathy, where the suffix “-pathy” refers to the damage itself^[1].

• Choroid
• Retina
• Vitreous
• Optic nerve head
• Sclera

Causes of Chorioretinitis

Chorioretinitis can have many different causes. Doctors usually divide them into two main groups: infectious causes and non-infectious causes^[2].

Infectious Causes

Infections are the most common reason people develop chorioretinitis. These infections can be present from birth or develop later in life^[1].

Toxoplasmosis is the most common cause of chorioretinitis. This is a parasitic infection that many people can get from cats or from eating undercooked meat^[1][2].

Other infectious causes include:

• Viruses such as cytomegalovirus (CMV), herpes simplex, rubella, Zika, West Nile virus, and varicella-zoster
• Tuberculosis
• Syphilis
• HIV-related eye diseases
• Fungal infections caused by Candida and other fungi
• Bartonella (from tick and flea bites)
• Toxocara (a parasitic infection)^[1][2]

In newborns, the infection may have been passed from mother to baby during pregnancy. This is called congenital infection^[3].

Non-Infectious Causes

Some cases of chorioretinitis are not caused by infection. These include:

• Eye injuries
• Autoimmune conditions (where your immune system attacks your own body), including rheumatoid arthritis, sarcoidosis, and Behçet’s disease
• Some types of cancer, such as lymphoma
• Some genetic conditions^[1][2]

Signs and Symptoms

The symptoms of chorioretinitis can vary from person to person. Some people notice vision changes right away, while others may have the condition without realizing it^[1].

Common symptoms include:

• Seeing black spots, floaters, or flashes of light in your vision
• Blurred vision
• Red eyes
• Eye pain or aching
• Sensitivity to light (called photophobia)
• Excessive tearing or watering of the eyes
• Difficulty seeing colors properly
• Objects appearing darker or dimmer than usual
• Dark spots in your central vision
• Straight lines appearing bent or crooked
• Impaired night vision^[1][4]

The condition can affect one or both eyes. In some cases, you might have chorioretinitis without experiencing any symptoms at all^[1].

Diagnosis and Testing

To diagnose chorioretinitis, an eye care provider will need to examine the back of your eye. The main way to do this is through a dilated eye exam^[1].

During this exam, your doctor will put special eye drops in your eyes to make your pupils wider. This allows them to see all the way to the back of your eye where your retina and choroid are located. Sometimes doctors can see scars or patches of color that indicate chorioretinitis^[1].

Additional Tests

Your provider may order several other tests to get more information:

• Lab tests on material swabbed from your eye to identify infections
• Optical coherence tomography – an imaging test that uses reflected light to take detailed pictures of the back of your eye
• Fluorescein angiography – a test that lets your provider see the blood vessels at the back of your eye
• Indocyanine green angiography – another imaging test to see the blood vessels in the choroid layer^[1]

If your doctor suspects an underlying condition is causing your chorioretinitis, they may order blood tests or other examinations^[1][4].

Treatment Options

Treatment for chorioretinitis depends on what is causing the inflammation. The main goal is to reduce inflammation and prevent vision loss^[1].

Anti-Inflammatory Treatment

Most cases of chorioretinitis are treated with steroids to reduce inflammation. However, you cannot take steroids for a long time because of side effects. Your eye doctor may work with other specialists to prescribe medications that spare you from long-term steroid use while still controlling your immune system^[1].

In some cases, your doctor might prescribe corticosteroid eye drops to treat the inflammation directly in your eye^[4].

Treating Infections

If your chorioretinitis is caused by an infection, your provider will prescribe specific medications to fight that infection:

• Antiviral medications for viral infections like CMV or herpes
• Antibiotics for bacterial infections like tuberculosis or syphilis
• Antiparasitic medications for toxoplasmosis and other parasitic infections
• Antifungal medications for fungal infections^[11][4]

For toxoplasmosis, the classic treatment includes a combination of three drugs: pyrimethamine, sulfadiazine, and prednisone. An additional medication called folinic acid is given to prevent side effects^[11].

Other Treatments

Depending on your symptoms, your doctor might also recommend:

• Dilating eye drops to reduce discomfort
• Laser treatment of affected areas in the retina
• In severe cases that don’t respond to medications, surgery called vitrectomy may be needed^[7]

Complications

The most serious complication of chorioretinitis is vision loss. If the condition is left untreated, this vision loss can become permanent^[1].

The choroid provides essential nutrients to your retina. When inflammation damages these structures, it can lead to serious vision problems. This is why immediate treatment is so important^[1].

Chorioretinitis is linked to a significant percentage of blindness cases. Studies show that uveitis (which includes chorioretinitis) causes between 2.8% and 10% of blindness in the United States^[2].

Prevention

While you cannot always prevent chorioretinitis, there are steps you can take to reduce your risk^[4]:

• Have regular eye exams, especially if you experience eye pain or vision problems
• Monitor and properly treat any autoimmune diseases you may have
• Avoid exposure to infections when possible – for toxoplasmosis, this means avoiding undercooked meat and being careful around cat litter
• If you feel eye discomfort, make an appointment with an eye doctor as soon as possible
• Practice good eye hygiene^[4]

If you develop symptoms like blurred vision, eye pain, or sensitivity to light, contact an eye care professional right away. Early treatment is critical for preventing complications and protecting your vision^[1].