Familial Exudative Vitreoretinopathy (FEVR)

Familial exudative vitreoretinopathy (FEVR) is a rare inherited retinal disease that affects the development of blood vessels in the retina. The retina is the light-sensitive tissue at the back of the eye responsible for vision.

In FEVR, the peripheral retina does not develop normal blood vessels. This poor blood vessel growth can lead to leakage, scar tissue formation, retinal dragging, and retinal detachment. The severity of FEVR varies greatly, even among members of the same family.

Some individuals have very mild disease and normal vision, while others may develop severe vision loss at a young age.

What Causes FEVR?

FEVR is a genetic condition caused by mutations in genes involved in retinal blood vessel development.

Several genes have been associated with FEVR, including:

FZD4
LRP5
NDP
TSPAN12

The condition may be inherited in different ways:

Autosomal dominant
Autosomal recessive
X-linked inheritance

Because FEVR runs in families, family members may also need retinal examinations even if they have no symptoms.

How Does FEVR Affect the Retina?

In FEVR, abnormal retinal blood vessel development can lead to:

Areas of poor retinal circulation
Leakage of blood vessels
Scar tissue formation
Retinal folds
Retinal detachment
Abnormal eye growth

The disease often affects both eyes, although one eye may be more severely involved.

Symptoms of FEVR

Symptoms can appear during infancy, childhood, or adulthood depending on disease severity.

Possible symptoms include:

Decreased vision
Misaligned eyes (strabismus)
Poor depth perception
White pupil reflex (leukocoria)
Floaters
Flashes of light
Sudden vision loss from retinal detachment

Some patients may have no symptoms and are diagnosed only after a family member is found to have FEVR.

How Is FEVR Diagnosed?

A retinal specialist diagnoses FEVR through a detailed retinal examination and specialized imaging tests.

Dilated Retinal Examination

The peripheral retina may show:

Incomplete blood vessel development
Scar tissue
Retinal dragging
Retinal folds or detachment

Fluorescein Angiography

This test uses fluorescent dye injected into a vein in the arm to evaluate retinal blood vessels and identify areas of poor circulation or leakage.

Wide-field angiography is especially helpful for examining the peripheral retina.

Optical Coherence Tomography (OCT)

OCT helps evaluate the macula and associated retinal changes.

Genetic Testing

Genetic testing may help confirm the diagnosis and identify affected family members.

Complications of FEVR

FEVR can lead to several serious retinal complications, including:

Retinal detachment
Vitreous hemorrhage (bleeding inside the eye)
Scar tissue formation
Macular dragging
Severe vision loss

Because the disease may progress over time, long-term monitoring is important.

Treatment for FEVR

Treatment depends on the severity of disease and the presence of complications.

Observation

Mild cases may only require regular monitoring with retinal examinations and imaging.

Laser Treatment or Cryotherapy

Areas of abnormal peripheral retina may be treated with laser or freezing therapy to reduce the risk of retinal complications.

Anti-VEGF Injections

In selected cases, anti-VEGF medications may help control abnormal blood vessel growth and leakage.

Vitrectomy Surgery

Advanced disease with retinal detachment or severe scar tissue may require surgery.

Vitrectomy surgery may involve:

Removing scar tissue
Repairing retinal detachments
Reattaching the retina

Some patients require multiple surgeries for complex retinal disease.

What Is the Prognosis?

The outlook for FEVR varies widely.

Some patients maintain excellent vision throughout life, while others develop severe retinal complications and vision loss.

Early diagnosis and treatment improve the chance of preserving vision.

Because progression can occur even in adulthood, lifelong follow-up with a retina specialist is often recommended.

Living With FEVR

Patients and families affected by FEVR may benefit from:

Regular retina specialist evaluations
Genetic counseling
Family screening examinations
Prompt evaluation of flashes, floaters, or vision changes
Low vision support services if needed

Protective eyewear may also be recommended during sports or activities with risk of eye injury.

Frequently Asked Questions

Is FEVR inherited?

Yes. FEVR is a genetic condition that runs in families. Several inheritance patterns are possible depending on the specific gene involved.

Can adults have FEVR?

Yes. Although FEVR often begins in childhood, some patients are not diagnosed until adulthood, especially if symptoms are mild.

Can FEVR cause retinal detachment?

Yes. Retinal detachment is one of the most serious complications of FEVR and may require urgent surgical treatment.

More Information

For additional patient information, visit the American Society of Retina Specialists FEVR Page