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The mission of this site is to provide an information source
for patients, families, doctors and researchers interested in
Familial Exudative Vitreoretinopathy as well as to provide
support for patients and families through education,
outreach and the knowledge that they are not alone.
GENERAL INFORMATION ABOUT FEVR
WHAT IS FEVR
Familial Exudative Vitreoretinopathy, written as, "FEVR," and pronounced by doctors as, "Fever," is a an eye disease affecting the retina which is found at the back of the eye, the vitreous, the clear, "gelatin like," substance inside the center of the eye and the blood vessels that feed the retina at the back of the eye. It is a genetic disease, meaning that it occurs in one or more family members. Its severity is vary unpredictable, even within the same family and even between eyes of the same person. It mostly occurs in people without any symptoms whatsoever causing no eye problems, but for some, it can cause minor to serious problems. In the cases where FEVR is serious, it usually shows up before the age of ten. When FEVR occurs in childhood it can be extremely variable causing some vision problems to blindness at birth.
PROBLEMS FEVR CAUSES
FEVR is a progressive disease, meaning that it continues to develop symptoms which over time lead to more and more serious problems. When occurring in it's aggressive form, the symptoms of abnormal blood vessel growth in the outer region of the retina the peripheral region, continue at a rapid and continuous pace. This abnormal blood vessel growth is due to a failure of peripheral retinal blood vessel growth (vascularization). Due to the lack of blood vessels, abnormal blood vessels grow and bleeding lead to dragging of the retina called retinal traction, and may result in scarring and/or retinal detachment due to the pulling of the retina. Very thin clear fibrous membranes can also grow into the vitreous gel in the center of the eye and can cause complications such as retinal dragging, detachment and retinal tearing due to the membranes pulling on the retina. The blood vessels also can exude a milky substance under the retina which can push up the retina and detach it from the back of the eye. If this continues than the retina can be destroyed in this region. (see picture of exudate). This progression of symptoms can continue into adolescence. Much medical intervention is needed throughout this time and the closer the child is watched and treated, when necessary, the better the chances of vision being saved. Usually FEVR stops progressing around age 20 but recent evidence shows that in the more aggressive cases, defined by the development of FEVR before age 10, FEVR can start progressing again in later life after a non-symptom (asymptomatic) period. Another problem a FEVR child can be born with is called a retinal fold. In this case the retina at birth is detached and falls or folds over onto itself usualy over the central vision. If this can be caught at birth they it may be possible to unfold the retina but most are not caught and the fold develops and can not be treated by any medical means. This can occur in one or both of the child's eyes. Other problems found in FEVR patients are cataracts, iris non-dialiation due to membrane growth between the lens and iris. Both of these problems can be treated with much success.
WHO GETS FEVR, IS IT A, "RARE" DISEASE
Scientists have shown that FEVR is found throughout the world but no scientific evidence has shown that it occurs at a higher frequency in one population over another. Scientists have shown that 85% of affected individuals can be asymptomatic, that is, showing no symptoms. Given this knowledge it is unknown whether FEVR is actually a, "Rare" disease, as it has been though in the past. Today genetic researchers believe that it is not as rare as it has been thought, but no concrete, scientific study have been conducted to show what percentage of the population actually has FEVR . In addition, it is known to be a complex diease with many genetic causes and is slowly being shown to be in some cases, more like a syndrome, rather than a disease since it can cause problems in other parts of the body and can occur along side other syndromes.
THE GENETICS OF FEVR
FEVR can occur in all three forms of genetic inheritance; 1. Recessive, 2. Dominant, and 3. x-linked,. As well as another mutation in a separate syndrome. The same disease or syndrome called FEVR is caused in people by a pair of defect genes but there are many defects that cause FEVR. More genes are found as time goes on by gene hunters around the world. The X-linked gene is known and can be tested for and only occur in males of the family. Some of the Dominant and Recessive FEVR's have been shown to be caused by many different genetic defects in many genes. A paper outlining the latest genetic research by many groups of researchers from around the world can be read by going to the web link below. It describes some of the genetic work being done to understand FEVR and recently the link between the the underdevelopment of the retina and the under and over development of bone density. The FEVR with low bone density is called osteoporosispseudoglioma syndrome (OPPG) and causes osteoporosis. High bone density is called Osteopetrosis. it can also cause low bone density but nnot as low as osteoporosis which is called . The more that is uncovered the more complex the problem becomes. Click the link below or continue down on this page to read more about FEVR.
http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&partid=1147#fevr or by CLICKING HERE
Genetic testing of your family can be requested by your eye doctor by you being included in a genetic study being preformed by the National Institute of Health Clinical Study. FEVR mutations have been found on the 11th chromosome. In its x-linked form it occurs only in the males of the family and most of the time is a mutation of the Norri Disease. Many times this form is caused by a mutation in the Norrie gene but there may be other genes causing this form too. A test is available to test for the Norrie Disease mutation which causes most X-linked forms of the disease. In its rarest form, recessive, it can occur with no family history. We are currently looking for people with ALL forms of FEVR. One paper shows that the recessive form of FEVR can be accompanied with low bone density causing a rare disease called osteoporosispseudoglioma syndrome (OPPG) and thus cause osteoporosis. Today, studies are now ongoing and more are in the progress of being reviewed and developed. See you can help page if you are interested in joining the fight for a cure e-mail me at young1@fevr.net for more information.
CAN FEVR LOOK LIKE OTHER DISEASES AND BE MISDIAGNOSED?
FEVR can be misdiagnosed as other non-genetic eye diseases such as Persistent Hyperplastic Primary Vitreous (PHPV) due to the lack of family history but unlike PHPV, FEVR may continue to change the retina with age. Many of the features of FEVR also resemble Retinopathy of Prematurity (ROP).
SUMMARY
FEVR is congenital (present at birth) and bilateral (affect both eyes) although not necessarily with the same intensity. FEVR may affect one eye more than the other, may affect one child more than another and in some cases may not affect sight at all or only slightly. Its outcome for each person is thus frustratingly unknown. Careful watching by a vitreo-retinal specialist with experience with FEVR is essential for the best outcome. Many FEVR patients also are born with retina folds in one or both eyes which cause blindness in that area of the vision. In these cases the retina does not form correctly in the womb. This condition, when present at birth, can potentially be helped but only in cases where the problem is found very early. In most cases the retina fold attaches to each other and can not be unfolded. FEVR is a progressive disease which may change and worsen throughout and entire lifetime but how much and how radical and how fast it progresses can not be predicted. In cases where it progresses, FEVR progresses commonly by bleeding in the abnormal areas of the eye which usually is the outer regions. Abnormal blood vessels break and bleed into the center region of the eye which is filled with a clear gel-like substance called the vitreous humor. The person will see wavy lines which is the blood. These abnormal blood vessels also exude a milky white substance which can be seen. If bleeding, one of the most common effects of FEVR, occurs, laser surgery (laser photocoagulation) may be warranted other drug treatments are being tried to prevent the abnormal blood vessels from growing out of control. These treatments are similar to the same treatments used for the eye diease macular degeneration. This procedure kills the abnormal blood vessels but also destroys the retina and the sight. Better technology is available today to minimize this loss of vision. The blood vessel growth which usually occurs in the outer edges of the retina can also occur anywhere on the retina. Fibrous membranes are also associated with FEVR and grow into the vitreous and attach to the retina and can cause traction or detachment of the retina. A surgeon can remove the membranes with a procecure called a vitrectomy. The most important thing a FEVR parent or patient can know is to find a good doctor who knows FEVR well and sees him/her whenever changes in sight occur no matter how small.
Most cases of FEVR don’t show any symptoms and never become a problem but for a minority it can be devastating. With diligent and at times aggressive treatment for these people, FEVR does not have to lead to blindness. Normal to impaired sight is common in at least one eye. Sometime complete blindness occurs. The closer a patient is watched and the knowledge of the doctor about FEVR and how to treat it can affect the outcome of a person. FEVR is a lifetime disease and should always be watched closely by a trained eye retinal & vitreous specialist.
WHEN TO OPERATE
Any operation has risks and thus the potential to cause other, sometimes serious problems, so care should be taken when deciding whether to perform an operation. The risks must always outweigh the benefits. if time allways, always get a second and if needed third opinion. This will give you confidence that you have done all that you can do in deciding to operate.
FINAL AND IMPORTANT THOUGHTS
A FEVR patient and family are encouraged to take one day at a time and if there are many operations both can benefit from some type of mental health help during their entire life. A mental health advocate can help enormously and should be incorporated into the treatment of FEVR especially if the patient is a child and it is thought that FEVR will remain active throughout their entire life. Pre and Post-Operative mental health care should be administered. FEVR does not just affect the eye; it affects the entire person both mind and body and should therefore be treated as such. This important fact can often be overlooked by eye specialists and the family may need to seek out help themselves or bring up the subject with their doctor themselves taking a more active approach to holistic (whole body and mind) treatment. A psychiatrist, which is an M.D., (doctor), deals best with an eye doctor and has the ability to help in the hospital as well. Much trauma can occur when a whole mind and body approach is not taken. One must understand that the eye doctor has no training in mental health and thus can overlook major problems caused by the continued treatments of FEVR. To loose ones sight is one of the top most feared disabilities people have. How the parents and people around the legally blind person can affect how she or he see her or himself. One doctor that became a patient said, "I am wonded, not stupid so treat me with respect and equality." Many stigmata's still exhist about seeking this kind of help but it may save your child't life in the end. Eye surgons and mother's and father's can't diagnose treatable mental health issues such as post-operative depression, pre-operative anxiety and trama from loss of sight. You wouldn't treat your daughter or son's FEVR yourself so don't think you can treat the emotional problems that will accompany FEVR your self. Seek out a doctor for that aspect of FEVR's treatment as well.
Jane Young
FEVR Patient for 41 years and over 30 surgeries and counting...
July 10, 2008
A good bulletin board where doctors answer questions is at The Public Forum. sponsored by American Association for Pediatric Ophthalmology and Strabismus (AAIPOS). I can't guarantee all the answers are correct but some helpful answers can be found. You can search the database for previously answered questions. Search for "FEVR" or "Familial Exudative Vitreoretinopathy"
Find more information about FEVR at American FEVR Research Consortium
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