Familial Exudative Vitreoretinopathy (FEVR)
In the autosomal dominant form several people in a family are affected and family members are often aware that there is condition causing visual impairment in the family. The other two inheritance patterns can skip generations, and one may not be aware that other family members are affected. This is particularly true if the family member is relatively mildly affected (i.e., with Stage 1 FEVR).
FEVR is a retinal vascular disease, which may remain active or recur throughout life. It occurs as a consequence of a biochemical imbalance between vascular endothelial growth factor and tissue growth factor beta.
FEVR has been treated by laser and surgical therapy in the past. Until recently, no effective drug therapy was available for FEVR. In the last few years a class of drugs targeting vascular endothelial growth factor, or VEGF, have been used in some eyes with FEVR. VEGF affects how blood vessels behave. Anti-VEGF drugs (Macugen initially, and more recently Avastin, Lucentis) have been used to reduce the abnormal "leakiness" of blood vessles in eyes with FEVR.
These drugs were approved by the FDA for use in age-related macular degeneration, but has been used in an off-label fashion in people affected with this very progressive, otherwise uncontrollable, form of familial exudative vitreoretinopathy with what appear to be very good results.
The results using Macugen were presented at the 2005 Pre-American Academy of Ophthalmology Retina Meeting by Dr. Kimberly Drenser, MD, PhD. For the first time there is a class of pharmacologic agents which seems to selectively encourage reabsorption of subretinal exudate (blood), a component of FEVR for which we had no acceptable treatment in the past.
ablation – The removal or destruction of tissue
acuity , visual acuity – Measure of the eye’s ability to distinguish object details and shape. This measurement is usually defined by the smallest detail the person can see at a specified distance (usually 20 feet or 6 meters).
20/20 or 6/6 – Normal visual acuity is identified when a person is able to read on an eye chart at a distance of 20 feet (or 6 meters) what is average to be seen at that distance.
20/200 – A reading of 20/200 on an eye chart means that the person can see at 20 feet what someone with average acuity can see at 200 feet. In the United States “legal blindness” is defined as 20/200 vision.
bilateral – Affecting both eyes.
ciliary processes – The innermost part of the tissue inside the eye. The 70 ciliary processes secrete aqueous fluid and acts as the attachment site for the ligaments that hold up the lens.
dysplasia – Abnormal development or growth of cells, tissues or organs.
electroretinography – Test which provides a measure of retinal functioning caused by light stimulation to the retina.
flourescein angiography (FA) – A test where vegetable based dye is injected into an arm vein, then rapid, sequential photographs are taken of the eye as the dye circulates.
lenticonus - An abnormal cone shaped protrusion of the lens, usually on the front surface.
opaque – A cloudiness which causes the inability of light to go through a normally transparent part in the eye.
mutations – A change in the genetic material passed down from an individiual’s parents.
O.C.T. – generates a cross-sectional image through the retina and gives information not found by F.A.
peripheral vision – side vision.
systemic – Affecting the body generally, rather than a specific area.
ultrasound – A test where the transmission of high frequency sound waves go into the eye and are reflected by the tissue in the eye and displayed on a screen so that the inside parts of the eye can be seen.
unilateral – Affecting only one eye.
vascular – Referring to a blood or lymph vessel.
vasculature – The arrangement of blood vessels in an organ or part.
visually evoked potential or response (VEP or VER) – A computerized test which records the electrical activity in the brain caused by stimulating the retina with light flashes. This test is used to determine whether the eye and brain and working together.