FEVR is short for Familial Exudative Vitreoretinopathy. A big name but actually it is simply a description of the condition which affects people around the world.
To make it easy to understand, lets break it up...Familial - This means that it runs in the "family" (i.e. a genetic disease) Exudative - Refers to the whitish fluid exuded from abnormal blood vessels. (see pictures of the fluid) Vitreo - Refers to a disease of the vitreous humor, the transparent gel like substance filling the eye. Retinopathy - Refers to abnormal changes in the blood vessels of the eye which feed the retina. The retina is the thin layer in the back of the eye which changes light into electrical signals which are then sent to the brain and decoded, giving us an image when we open our eye(s).
FEVR is a variable disease which means it varies in intensity from person to person. Severe cases of FEVR can cause a number of eye problems such as
FEVR is a genetic disease. While its causes at this time cannot be treated or cured, its symptoms can be. Each symptom has its individual treatments (see Question 3). Today effective and aggressive treatment can save much sight.
Some Treatments commonly found in FEVR patients
Laser photocoagulation - The application of intense light or laser beams to burn or destroy selected intraocular structures under direct observation, e.g., abnormal blood vessels. More from U-M Kellogg Eye Center . Both laser surgery and cryotherapy are done on an outpatient basis. Patients may return to full activity, without restrictions, in a short period of time. Vision may be blurred for several days following laser or cryotherapy. If cryotherapy is used to treat the retinal tear, the eye may be red for several weeks.
Vitrectomy - A Vitrectomy is used to save vision. This procedure involves the surgical removal of the clear vitreous gel in the eye and replacement during the operation with saline air or silicon oil that completely fills the eye.. The FDA approved the use of silicone oil in 1994, it is a new product for reattaching the retina in certain complicated cases of retinal detachment. If silicon oil is put in the eye it must be removed at a later time. A long-acting gas can also be inserted into the eye instead of saline or oil. The gas bubble, if the face is turned down toward the floor, can help push the retina back onto the back of the eye. NIH currently has a clinical study to way the benefits of gas vs. oil. Vitreous surgery is performed in a hospital, usually under general anesthesia. The surgeon uses a fiber optic light to illuminate the inside of the eye and other instruments inside the eye, such as forceps, and scissors, to do the surgery.
A Cataract, which can be taken care of later, is a major risk factor in this procedure. In one study, 63% of eyes that had had a vitrectomy developed cataracts compared to only 4% in the non-vitrectomised eye. Fortunately, vitrectomy is only used to prevent a more serious form of vision loss, and when treatment is recommended by an ophthalmologist it is clearly necessary.
Scleral Resection - Scleral resection is a surgical technique done to repair retinal detachment and to relieve traction (dragging) of the retina common in FEVR patients. In the procedure a small section of the eye wall (scleral) is removed.
Scleral Buckling - Scleral buckling is a surgical technique to repair retinal detachments due to traction which is seen in FEVR patients. In traction, the retina is pulled towards it's outer edges. When this happens tearing of the retina and detachment can occur. A Silicone rubber band is placed onto the scleral (the white out side of the eye ball) Silicone, a synthetic rubber compound of silicon, oxygen and carbon, is hydrophobic and stable within a very wide temperature range. Silicone retinal implants are economical, soft, biochemically inert, non-allergenic, and are well tolerated by the body. In vivo, they remain soft and retain their other physical properties for an extended period. They also retain these properties in extended storage. Buckling is sometimes also performed after scleral resections.
Seeing a retinal specialist is the first step in determining whether you have FEVR. A complete ocular (eye) examination needs to be performed including:
After the retinal specialist determines that your case may be FEVR genetic testing and a family history evaluation by a genetic counselor can be done.
The majority of cases of FEVR are dominant. The gene for the dominant form of FEVR has been found an a genetic test has been developed by the Canadian lab who discovered the gene. The test is not commercially available yet. (Return here for soon to come info on this)
In some cases, a mutation of the gene causing Norrie Disease has caused the X-Linked form of FEVR, the second most common form of FEVR. In the X-linked form of FEVR only males in the family have the disease. A genetic test may be done to determine this. Click below for details.
Unfortunately, in the most rarest cases, recessive, the gene causing they FEVR has not been found. We are currently looking for families with this form of FEVR. A study to find this form of FEVR is currently in the approval stage. (Click here for more on the study)
The symptoms of FEVR are like many other retina eye problems. They can include:
Symptoms of retina detachment - Flashing lights in one eye, Floaters, and Gray curtain or veil moving across your field of vision
more soon to come...
All three forms of FEVR are caused by defective gene . The three forms of FEVR are recessive, dominant and X-linked.
In the X-linked form of FEVR only males have the disease. In some cases, the X-Linked FEVR is caused by a mutation of Norrie disease (ND). Mutations in the NDP gene are associated with a spectrum of retinal findings ranging from Norrie disease (ND) to X-linked familial exudative vitreoretinopathy (FEVR), including some cases of persistent hyperplastic primary vitreous (PHPV), Coats disease, and advanced retinopathy of prematurity (ROP)
A test for the mutation is available. There is still debate as to how many cases of x-linked FEVR are caused by the mutation.
For the latest paper on the causes of the 3 dominant genes (click here)
Here are some helpful links about recessive, dominant and X-linked inheritance
Here are some Medical Papers On each form of FEVR
Although genetic testing is the only "full proof" way to tell which version of FEVR a person has, a family survey can sometimes eliminate the options. X-linked for example, runs only in the males of the family so if a girl in the family has FEVR you know it is either dominant or recessive. In Dominant families the disease tends to show up in many generations. Recessive is more rare than dominant.
As of yet, no test for the recessive or dominant gene exists. More research is needed to make this possible. The dominant gene has been identified to be on the 11th chromosome but it's exact location has still not been found.
If you or your family has FEVR and would be interested in helping to find the gene for recessive & dominant click here.
Yes, FEVR is similar to:
FEVR is a variable disease. The level of severity in a person can range from no symptoms to severe symptoms. The severity can even vary between eyes of the same person. In short, itís hard to predict with certainty the prognosis of any one person. This uncertainty of taking things "one day at a time" can be very frustrating to for families.
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Right Eye Left Eye View Source Paper
SLIDES OF THE EYE - ophthalmologic images
In many cases a replacement solution that can be
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