Introduction
A rare hereditary vitreoretinal disorder called familial exudative vitreoretinopathy (FEVR) is characterized by abnormal or incomplete vascularization of the peripheral retina, which can have a variety of clinical manifestations, minor anomalies, or even retinal detachment with blindness. Progressive vision loss may result from this condition. This disease impacts the retina, a specialized type of light-sensitive tissue that lines the back of the eye. The condition limits the development of blood vessels at the retina's borders, decreasing the blood flow to the affected area. The incidence of familial exudative vitreoretinopathy is unclear. It appears to be uncommon, yet affected people with normal vision may never seek medical attention.
What Is Familial Exudative Vitreoretinopathy?
Familial exudative vitreoretinopathy (FEVR) refers to a category of inherited retinal illnesses characterized by defective retinal angiogenesis, which results in inadequate vascularization of the peripheral retina and consequent retinal ischemia. The avascular retina in familial exudative vitreoretinopathy is thought to cause hypoxia and stimulate neovascular growth into the vitreous, resulting in subsequent vitreoretinal traction, subretinal exudation, and hemorrhages. Familial exudative vitreoretinopathy is also linked to increased vascular permeability and can manifest as exudative retinal detachment.
With varying penetrance, familial exudative vitreoretinopathy is genetically heterogeneous. Even among affected members of the same family, the clinical presentation of familial exudative vitreoretinopathy can be highly variable and asymmetric. Patients with mild disease may show no symptoms, while those with severe disease may present with substantial vision loss. X-linked recessive, autosomal dominant, or recessive inheritance patterns are all possible for the illness.
What Causes Familial Exudative Vitreoretinopathy?
A genetic anomaly that impairs the development and expansion of retinal blood vessels results in familial exudative vitreoretinopathy. Familial exudative vitreoretinopathy can be brought on by mutations in the FZD4, LRP5, and NDP genes. These genes give instructions for the production of proteins that take part in a chemical signaling pathway that influences the growth of cells and tissues. Particularly, the specialization of retinal cells and the formation of a blood supply to the retina and the inner ear appear to be critically dependent on the proteins made by the FZD4, LRP5, and NDP genes. The LRP5 protein also controls the development of bones. During early development, chemical signaling is disrupted by mutations in the FZD4, LRP5, or NDP genes, which obstruct the growth of blood vessels at the retina's margins. In some people with familial exudative vitreoretinopathy, the aberrant blood flow to this tissue causes retinal damage and visual loss.
What Are the Symptoms Associated With Familial Exudative Vitreoretinopathy?
Individuals may experience various variations of these symptoms. Symptoms can range from moderate to severe, and some people may experience them more frequently than others.
1. Vitreoretinopathy: Premature vitreous and retinal degeneration are the hallmarks of an ocular condition that may enhance the risk of retinal detachment.
2. Distortion in the Optic Disc: A morphological anomaly of the optic disc or of the part of the optic nerve can be seen under a fundoscopy and is, therefore clinically evident.
3. Falciform Retinal Fold: A region of the retina that has buckled, causing a sheet of retina the shape of a sector to protrude in front of the healthy retina. This condition has a congenital onset.
4. Retinal Neovascularization: Neovascularization (NV) is the process of repairing or replacing damaged vessels in a wound by sprouting new blood vessels from already-existing ones. Neovascularization is a result of ischemia in the retina. The outer surface of the vitreous and the inner surface of the retina both support neovascularization. Tight connections are lacking in neovascularization, which causes plasma leakage into surrounding tissue, including the vitreous. The vitreous gel deteriorates, contracts, and eventually collapses as a result of plasma pulling on the retina. As the vitreous compresses, the retinal neovascularization, which is attached to both the retina and the vitreous, may shear, leading to vitreous hemorrhage, or it may remain intact and pull the retina with the vitreous, causing retinal elevation and that known as traction retinal detachment.
What Are the Treatment Modalities Associated With Familial Exudative Vitreoretinopathy?
In order to avoid complications like retinal tears and detachments, the main goal of treatment is to lessen the rate of new blood vessel formation. Ophthalmologists perform a procedure called laser photocoagulation, in which they burn off the retinal tissue that is not sustained by blood vessels. This tissue will thereafter stop secreting chemicals that encourage the formation of blood vessels. For the retina to be repaired after a retinal detachment, laser therapy or surgery may be needed.
Conclusion
Familial exudative vitreoretinopathy (FEVR) has the potential to impair vision gradually. By preventing blood vessels from developing at the retina's margins, this disorder has an impact on the retina, the light-sensitive tissue that lines the back of the eye. As a result, the retina receives less blood. A visible whiteness (leukocoria) can be seen in the normally black pupil, vision loss or blindness, retinal detachment, strabismus (squint eye), and other signs and symptoms. Even within the same family, there are significant variations in familial exudative vitreoretinopathy severity. Many people who have this condition do not have any issues with their vision. Depending on the gene involved, familial exudative vitreoretinopathy has various inheritance patterns. To know more about this condition, consult a doctor online.
