Birdshot Chorioretinopathy

What is birdshot chorioretinopathy?

Birdshot chorioretinopathy (koor-ee-oh-reht-in-OHP-ah-thee), or BSCR, is a rare inflammatory eye disease. It’s a long-term (chronic) condition that can lead to permanent vision changes or complete loss of sight.

BSCR is a severe form of uveitis, a group of diseases that damage eye tissue. It causes swelling of the:

• Retina, the light-sensitive tissue at the back of your eye.
• Choroid, which connects your retina to the white part of your eye.

Hallmark signs of birdshot chorioretinopathy are cream-colored oval spots that are present in the deep retina and superficial (top layer) choroid. Early symptoms often involve floaters, blurred vision or both. The condition usually affects both eyes.

Over time, damage can cause cystoid macular edema or glaucoma. While there's no cure, birdshot chorioretinopathy is a treatable disease. Early detection is essential to the success of the treatment.

Who gets birdshot chorioretinopathy?

Anyone can develop birdshot chorioretinopathy. It most often affects middle-aged, white adults between the ages 40 and 60. It rarely affects children.

Are there other conditions like birdshot chorioretinopathy?

Several conditions, including other forms of uveitis, have symptoms that resemble birdshot chorioretinopathy. Getting an accurate diagnosis is crucial so you can get appropriate treatment. Conditions similar to BSCR include:

• Lymphoma.
• Sarcoidosis.
• Sympathetic ophthalmia, a rare type of uveitis caused by trauma to your eye.
• Syphilis.
• Presumed ocular histoplasmosis syndrome (POHS).
• Tuberculosis.
• Vogt-Koyanagi-Harada syndrome, a nervous system disease that affects vision and hearing.

A group of inflammatory conditions known as white dot syndromes also share symptoms of BSCR. They cause damage (lesions) to the retina and choroid and include:

• Acute posterior multifocal placoid pigment epitheliopathy (APMPPE).
• Multifocal choroiditis and panuveitis (MCP).
• Multiple evanescent white dot syndrome (MEWDS).
• Punctate inner choroidopathy (PIC).

Why is it called birdshot chorioretinopathy?

Birdshot chorioretinopathy is a relatively new disease, first described in 1949. In 1980, two eye specialists named it “birdshot chorioretinopathy” for its unique cream and orange oval-shaped spots scattered throughout the retina. The spots resemble the pattern from birdshot, small shotgun pellets (bullets).

Are there other names for birdshot chorioretinopathy?

Other names for birdshot chorioretinopathy are:

• Birdshot chorioretinitis.
• Birdshot retinochoroiditis.
• Birdshot retinochoroidopathy.
• Birdshot uveitis.
• BSCR.
• Posterior uveitis.
• Vitiliginous choroiditis.

How common is birdshot chorioretinopathy?

Birdshot chorioretinopathy is rare. Researchers believe it affects less than 1 in every 100,000 people.

What causes birdshot chorioretinopathy?

Researchers don’t know the exact cause of birdshot chorioretinopathy. They suspect it may be an autoimmune disease, when your body's immune system mistakenly attacks healthy tissues.

More than 90% of people diagnosed with BSCR inherit (receive from their parents) a substance (antigen) called HLA-A29 that triggers an immune response. However, you don't need to have HLA-A29 to develop birdshot chorioretinopathy. You can also have the antigen and not get the disease.

What are the symptoms of birdshot chorioretinopathy?

Symptoms of birdshot chorioretinopathy can vary. It's a progressive disease with symptoms that typically worsen over several months to years.

The first signs of birdshot chorioretinopathy are often floaters or blurred vision. BSCR does 't usually involve eye pain or redness. You may also experience:

• Changing vision or vision loss.
• Decreased ability to see to the side (peripheral vision) or judge depth.
• High eye pressure (ocular hypertension).
• Night blindness (nyctalopia).
• Problems with color vision (color blindness) and telling certain colors apart (dyschromatopsia).
• Sensitivity to bright lights or glare (photophobia).

Some people experience unusual changes in vision or perception. Symptoms may include:

• Ceiling fan effect (when you close your eyes, you see something like a ceiling fan or pinwheel whirring around).
• Seeing flashing or flickering lights (photopsia) or distorted shapes (metamorphopsia).
• Shimmering blurred or hazy vision (like looking through water or dirty glass).

In severe cases, symptoms may include cataracts or glaucoma, which can cause severe vision loss even after inflammation is treated. Birdshot chorioretinopathy may also lead to issues with the central retina, including cystoid macular edema and epiretinal membranes.

How is birdshot chorioretinopathy diagnosed?

Diagnosis of birdshot chorioretinopathy can be difficult. It's a rare disease, and its unique spots may not be visible in early stages of the disease.

Eye care specialists (ophthalmologists) most often diagnose BSCR with an eye exam. They also use a blood test to confirm that you have the HLA-A29 antigen.

Healthcare providers may use a combination of tests to monitor you over time. Stay in touch with your provider to receive the care you need.

Is there a cure for birdshot chorioretinopathy?

There's no cure for birdshot chorioretinopathy. But with timely diagnosis, treatment can reduce symptoms and prevent worsening of the disease.

Who might be on my treatment team for birdshot chorioretinopathy?

Your care team recommends treatment, monitors you and adjusts medications based on your condition and any side effects. Your team may include:

• Eye specialist (ophthalmologist).
• Kidney (renal) specialist (nephrologist).
• Eye specialist with special training in immune disorders (ocular immunologist).
• Inflammatory disease specialist (rheumatologist).
• Musculoskeletal specialist (orthopaedist).

How is birdshot chorioretinopathy treated?

Treatment for birdshot chorioretinopathy depends on the severity of your condition and how it changes over time. The goal of treatment is to reduce swelling in your eyes and prevent or reverse vision loss.

Healthcare providers typically first recommend high doses of corticosteroids to control inflammation in your eye. They then lower the dose as much as possible due to the risk of side effects. You may receive steroids through:

• Eye drops.
• Oral medicines.
• Implant placed surgically in your eye (intravitreal implant).
• Injection.
• IV (intravenously, through a vein).

Many people also need long-term treatment with immunosuppressants. These drugs stop your immune system from attacking your eyes and may include one or more:

• Alkylating agents.
• Antimetabolite drugs.
• Biologic agents.
• T-cell transduction/calcineurin inhibitors.

Are there any side effects from birdshot chorioretinopathy treatment?

Long-term steroid and immunosuppressant use can cause serious side effects, including gastrointestinal or bone issues. They may also increase your risk of developing cataracts or glaucoma.

Your healthcare provider will monitor you for any side effects and prescribe other medications if needed. If you're taking steroids by mouth, providers will check you for bone damage (osteoporosis) and fracture risk.

Your provider may also recommend a bone density scan. You may receive medication to prevent bone loss (bisphosphonates).

What kind of ongoing monitoring will I have for BSCR?

Watch your condition for any changes or complications. Your healthcare provider will check your blood and urine to make sure your kidneys, liver and bone marrow are working as they should. You are also likely to have regular eye exams, including visual field tests and optical coherence tomography (OCT) scans.

What’s the outlook for birdshot chorioretinopathy?

The outlook for birdshot chorioretinopathy varies depending on the severity of the condition and the effectiveness of treatment. In milder cases, vision can remain stable or improve with treatment.

How can I reduce my risk of developing birdshot chorioretinopathy?

There's no known way to prevent birdshot chorioretinopathy. In most cases, it's believed to be triggered by a specific antigen (a molecule that triggers an immune response) passed down in families.

Regular eye exams can help detect early symptoms, so you can receive timely treatment if needed. Tell your healthcare provider if any family members have eye disease.

When should I seek care for birdshot chorioretinopathy?

Birdshot chorioretinopathy requires prompt diagnosis and treatment from an ophthalmologist. Even if your vision is fine, an eye exam can detect low levels of inflammation.

Alert your healthcare provider to any side effects of medication or change in symptoms or vision. You may receive different medications as needed. Your healthcare provider can discuss options that work best for you.