Branch retinal vein occlusion | |
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Branch retinal vein occlusion | |
Specialty | Neurology |
Branch retinal vein occlusion is a common retinal vascular disease of the elderly. It is caused by the occlusion of one of the branches of central retinal vein. [1]
Patients with branch retinal vein occlusion usually have a sudden onset of blurred vision or a central visual field defect. The eye examination findings of acute branch retinal vein occlusion include superficial hemorrhages, retinal edema, and often cotton-wool spots in a sector of retina drained by the affected vein. The obstructed vein is dilated and tortuous.
The quadrant most commonly affected is the superotemporal (63%).
Retinal neovascularization occurs in 20% of cases within the first 6–12 months of occlusion and depends on the area of retinal nonperfusion. Neovascularization is more likely to occur if more than five disc diameters of nonperfusion are present and vitreous hemorrhage can ensue. [2]
Studies have identified the following abnormalities as risk factors for the development of branch retinal vein occlusion:
Diabetes mellitus was not a major independent risk factor.[ citation needed ]
The diagnosis of branch retinal vein occlusion is made clinically by finding retinal hemorrhages in the distribution of an obstructed retinal vein.
Several options exist for the treatment of branch retinal vein occlusion. These treatments aim for the two of the most significant complications, namely macular edema and neovascularization. [1]
In general, branch retinal vein occlusion has a good prognosis: after 1 year 50–60% of eyes have been reported to have a final visual acuity of 20/40 or better even without any treatment. With time the dramatic picture of an acute branch retinal vein occlusion becomes more subtle, hemorrhages fade so that the retina can look almost normal. Collateral vessels develop to help drain the affected area.
Retinopathy is any damage to the retina of the eyes, which may cause vision impairment. Retinopathy often refers to retinal vascular disease, or damage to the retina caused by abnormal blood flow. Age-related macular degeneration is technically included under the umbrella term retinopathy but is often discussed as a separate entity. Retinopathy, or retinal vascular disease, can be broadly categorized into proliferative and non-proliferative types. Frequently, retinopathy is an ocular manifestation of systemic disease as seen in diabetes or hypertension. Diabetes is the most common cause of retinopathy in the U.S. as of 2008. Diabetic retinopathy is the leading cause of blindness in working-aged people. It accounts for about 5% of blindness worldwide and is designated a priority eye disease by the World Health Organization.
Diabetic retinopathy, also known as diabetic eye disease (DED), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries.
Hypertensive retinopathy is damage to the retina and retinal circulation due to high blood pressure.
Vitrectomy is a surgery to remove some or all of the vitreous humor from the eye.
Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye and causes it to thicken and swell (edema). The swelling may distort a person's central vision, because the macula holds tightly packed cones that provide sharp, clear, central vision to enable a person to see detail, form, and color that is directly in the centre of the field of view.
Eales disease is a type of obliterative vasculopathy, also known as angiopathia retinae juvenilis, periphlebitis retinae, primary perivasculitis of the retina. It was first described by the British ophthalmologist Henry Eales (1852–1913) in 1880 and is a rare ocular disease characterized by inflammation and possible blockage of retinal blood vessels, abnormal growth of new blood vessels (neovascularization), and recurrent retinal and vitreal hemorrhages. This disease is identified by its three characteristic steps: vasculitis, occlusion, and retinal neovascularization, leading to recurrent vitreous hemorrhages and vision loss. Eales Disease with a characteristic clinical picture, fluorescein angiographic finding, and natural course is considered a specific disease entity. The exact cause of this disease is unknown but it appears to affect individuals that are from Asian subcontinents. This disease tends to begin between the ages of 20-30 years and begins with unilateral peripheral retinal perivasculitis and peripheral retinal capillary non-perfusion. These are not normally recognized until the inflammation results in vitreous hemorrhage. This disease has been found to affect the second eye 50-90% of the time so there is a large chance that both eyes will begin to show signs of the disease.
Intravitreal is a route of administration of a drug, or other substance, in which the substance is delivered into the vitreous humor of the eye. "Intravitreal" literally means "inside an eye". Intravitreal injections were first introduced in 1911 when Ohm gave an injection of air into the vitreous humor to repair a detached retina. In the mid-1940s, intravitreal injections became a standard way to administer drugs to treat endophthalmitis and cytomegalovirus retinitis.
Rubeosis iridis, is a medical condition of the iris of the eye in which new abnormal blood vessels are found on the surface of the iris.
Ranibizumab is a monoclonal antibody fragment (Fab) created from the same parent mouse antibody as bevacizumab. It is an anti-angiogenic that has been approved to treat the "wet" type of age-related macular degeneration, diabetic retinopathy, and macular edema due to branch retinal vein occlusion or central retinal vein occlusion.
Pegaptanib sodium injection is an anti-angiogenic medicine for the treatment of neovascular (wet) age-related macular degeneration (AMD). It was discovered by NeXstar Pharmaceuticals and licensed in 2000 to EyeTech Pharmaceuticals, now OSI Pharmaceuticals, for late stage development and marketing in the United States. Gilead Sciences continues to receive royalties from the drugs licensing. Outside the US pegaptanib is marketed by Pfizer. Approval was granted by the U.S. Food and Drug Administration (FDA) in December 2004.
Intermediate uveitis is a form of uveitis localized to the vitreous and peripheral retina. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed. Intermediate uveitis may either be an isolated eye disease or associated with the development of a systemic disease such as multiple sclerosis or sarcoidosis. As such, intermediate uveitis may be the first expression of a systemic condition. Infectious causes of intermediate uveitis include Epstein-Barr virus infection, Lyme disease, HTLV-1 virus infection, cat scratch disease, and hepatitis C.
Choroidal neovascularization (CNV) is the creation of new blood vessels in the choroid layer of the eye. Choroidal neovascularization is a common cause of neovascular degenerative maculopathy commonly exacerbated by extreme myopia, malignant myopic degeneration, or age-related developments.
Central retinal vein occlusion, also CRVO, is when the central retinal vein becomes occluded, usually through thrombosis. The central retinal vein is the venous equivalent of the central retinal artery and both may become occluded. Since the central retinal artery and vein are the sole source of blood supply and drainage for the retina, such occlusion can lead to severe damage to the retina and blindness, due to ischemia and edema (swelling).
Macular telangiectasia is a condition of the retina, the light-sensing tissue at the back of the eye that causes gradual deterioration of central vision, interfering with tasks such as reading and driving.
Vitreomacular adhesion (VMA) is a human medical condition where the vitreous gel of the human eye adheres to the retina in an abnormally strong manner. As the eye ages, it is common for the vitreous to separate from the retina. But if this separation is not complete, i.e. there is still an adhesion, this can create pulling forces on the retina that may result in subsequent loss or distortion of vision. The adhesion in of itself is not dangerous, but the resulting pathological vitreomacular traction (VMT) can cause severe ocular damage.
Radiation retinopathy is damage to retina due to exposure to ionizing radiation. Radiation retinopathy has a delayed onset, typically after months or years of radiation, and is slowly progressive. In general, radiation retinopathy is seen around 18 months after treatment with external-beam radiation and with brachytherapy. The time of onset of radiation retinopathy is between 6 months to 3 years.
Anti–vascular endothelial growth factor therapy, also known as anti-VEGF therapy or anti-VEGF medication, is the use of medications that block vascular endothelial growth factor. This is done in the treatment of certain cancers and in age-related macular degeneration. They can involve monoclonal antibodies such as bevacizumab, antibody derivatives such as ranibizumab (Lucentis), or orally-available small molecules that inhibit the tyrosine kinases stimulated by VEGF: lapatinib, sunitinib, sorafenib, axitinib, and pazopanib.
Intravitreal injection is the method of administration of drugs into the eye by injection with a fine needle. The medication will be directly applied into the vitreous humor. It is used to treat various eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and infections inside the eye such as endophthalmitis. As compared to topical administration, this method is beneficial for a more localized delivery of medications to the targeted site, as the needle can directly pass through the anatomical eye barrier and dynamic barrier. It could also minimize adverse drug effect to other body tissues via the systemic circulation, which could be a possible risk for intravenous injection of medications. Although there are risks of infections or other complications, with suitable precautions throughout the injection process, chances for these complications could be lowered.
Sickle cell retinopathy is a major ocular complication of the sickle cell disease (SCD) which causes permanent loss of vision. Retinopathy can occur in sickling hemoglobinopathies like sickle cell disease, sickle cell C disease, and sickle cell thalassaemia disease.
Conbercept, sold under the commercial name Lumitin, is a novel vascular endothelial growth factor (VEGF) inhibitor used to treat neovascular age-related macular degeneration (AMD) and diabetic macular edema (DME). The anti-VEGF was approved for the treatment of neovascular AMD by the China State FDA (CFDA) in December 2013. As of December 2020, conbercept is undergoing phase III clinical trials through the U.S. Food and Drug Administration’s PANDA-1 and PANDA-2 development programs.
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