Branch Retinal Vein Occlusion - Patients - The American Society of Retina Specialists
`
`Facts from the Foundation of the ASRS
`RETINA HEALTH SERIES
`Committed to improving the quality of life of
`all people with retinal disease
`
`Branch Retinal Vein Occlusion
`Retinal vein occlusions occur when there is a blockage of veins
`carrying blood with needed oxygen and nutrients away from the
`nerve cells in the retina. A blockage in the retina’s main vein is
`referred to as a central retinal vein occlusion (CRVO), while a
`blockage in a smaller vein is called a branch retinal vein occlusion
`(BRVO).
`
`Download Fact Sheet
`
` DOWNLOAD LARGE PRINT VERSION
`
`
`
`Spanish Translation
`
`Symptoms
`BRVO causes a sudden, painless loss of vision. If the
`affected area is not in the center of the eye, BRVO can go
`unnoticed with no symptoms.
`
`In rare cases of an undetected vein occlusion, visual floaters
`from a vitreous hemorrhage (blood vessels leaking into the
`vitreous gel of the eye) can be the main symptom; this is
`caused by development of abnormal new blood vessels
`(neovascularization) in the retina.
`
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 01 of 06
`
`

`

`BranchRetinal Vein Occlusion- Patients - The American Society of Retina Specialists
`
`Causes
`
`Most BRVOsoccurat an arteriovenous crossing—anintersection between a retinal artery and vein. These vessels
`share a common sheath (connective tissue), so when the artery losesflexibility, as with atherosclerosis (hardening of
`the arteries), the vein is compressed.
`
`leading to a blockage or occlusion. This
`The narrowed vein experiences turbulent blood flow that promotesclotting,
`obstruction blocks blood drainage and maylead to fluid leakage in the center of vision (macular edema) and
`ischemia—poorperfusion (flow) in the blood vessels supplying the macula.
`
`
`
`Figure 1. Branch retinal vein occlusion: Retinal
`hemorrhagein only a sectorof the retina is seen.
`Cotton-woolspots (white lesions amid the
`hemorrhages)signify focal ischemia (inadequate
`blood supply). Foveal edema (swelling withfluid)is
`also present. Photo courtesy Anat Loewenstein, MD
`
`
`
`Figure 2. BRVO with macular edema. David Callanan,
`MD, Texas Retina Associates. BRVO/CHRPE.Retina
`Image Bank 2014; Image 15926. © American Society
`of Retina Specialists.
`
`RISK FACTORS
`
`The commonrisk factors for BRVO are:
`
`e Uncontrolled high blood pressure
`
`e Being overweight or obese (increased body massindex)
`
`e Cardiovascular (heart) disease
`
`e Glaucoma
`
`In younger patients who suffer BRVO, an abnormaltendency to develop blood clotting is also possible
`
`Diagnostic testing
`
`Exhibit 2150
`
`Page 02 of 06
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[ 12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 02 of 06
`
`

`

`Branch Retinal Vein Occlusion - Patients - The American Society of Retina Specialists
`
`Most often, BRVO is diagnosed by an eye exam that shows retinal hemorrhage (blood vessels leaking into the retina),
`thickened and twisted blood vessels, and retinal edema (swelling with fluid).
`
`Two types of retinal imaging tests aid the diagnosis of BRVO:
`
`Fluorescein angiography (FA)
`Optical coherence tomography (OCT)
`
`FA provides images of fluid leaking from damaged or abnormal retinal
`vessels, demonstrating:
`
`Venous stasis (congestion and slowing of circulation)
`Edema (swelling with fluid)
`Ischemia (inadequate blood supply) or
`Retinal neovascularization (abnormal growth of new blood vessels in the retina)
`
`Figure 3 OCT image of macular edema secondary to
`BRVO. There is a cystoid macular edema mainly in the
`superior part of the macula, effecting the superior
`temporal vein. Photo courtesy of Anat Loewenstein, MD
`
`OCT provides detailed images of the central retina, allowing detection of macular edema and fluid outside the macula
`(Figure 3).
`
`FA is very valuable for detecting BRVO and the flow of the blood vessels. Once BRVO has been found, OCT is used to
`provide a better assessment of whether macular edema is present, and if so, how severe it is.
`
`Treatment and prognosis
`Treatment begins with identifying underlying risk factors and treating them. Risk factors are assessed using several
`methods:
`
`Blood pressure monitoring
`Determining if blood cholesterol or lipid levels are elevated
`Blood tests, if appropriate, to determine if there is an abnormal tendency to form blood clots
`
`Eye treatment is aimed at treating retinal complications rather than at trying to relieve the blockage itself. Macular
`edema, the main reason for visual loss from BRVO, is often treated with intraocular (in-the-eye) injections of anti-
`VEGF drugs designed to stop the growth of abnormal new blood vessels in the eye and decrease leakage. Local
`anesthetic eye drops are given before the injections to numb the eye and minimize discomfort.
`
`There are currently 3 anti-VEGF drugs:
`
`Avastin® (bevacizumab®)
`Lucentis® (ranibizumab®)
`Eylea® (aflibercept®)
`
`In several large clinical studies, all 3 of these anti-VEGF drugs have demonstrated good results, with over 50% of
`patients enjoying significant visual improvement. The use of these drugs may require frequent retreatment, but
`
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 03 of 06
`
`

`

`Branch Retinal Vein Occlusion - Patients - The American Society of Retina Specialists
`
`injection schedules are determined on a case-by-case basis.
`
`Laser treatment may be used along with anti-VEGF therapy in hard-to-treat cases. Laser therapy for macular edema
`involves applying light laser pulses to the macula in a grid pattern. In a large multi-center clinical trial, after 3 years of
`follow up, this treatment showed improvement of vision in approximately two-thirds of patients.
`
`Intraocular injections of steroids are another potential treatment for eyes that don’t respond to anti-VEGF drugs. A
`clinical trial that evaluated steroid treatment using a slow-releasing steroid implanted in the eye (dexamethasone or
`Ozurdex®), showed that approximately 30% of BRVO patients enjoyed significant visual improvement following
`treatment.
`
`While intraocular steroids can have some side effects such as an increase in eye pressure and cataract progression, in
`most cases, these side effects can be controlled.
`
`Overall, BRVO carries a generally good prognosis. In fact, some BRVO patients don’t require treatment at all, either
`because the blockage did not involve the macula, or because they have not experienced a decrease in vision. Over
`60% of patients, treated and untreated, maintain vision better than 20/40 after 1 year.
`
`Complications
`
`Retinal neovascularization is a potentially serious complication of BRVO in which an inadequate blood supply
`(ischemia) causes abnormal new blood vessels to grow on the surface of the retina. This growth can further
`decrease vision by causing vitreous hemorrhage that causes floaters and loss of vision, retinal detachment,
`and glaucoma.
`
`When neovascularization develops, scatter laser photocoagulation therapy is used to create burns in the area of the
`vein occlusion (blockage). The aim is to try to lower the oxygen demand of the retina and thus stop the abnormal
`blood vessels from growing. Patients receive an anesthetic to numb the eye and make the treatment more
`comfortable.
`
`Scatter photocoagulation has been shown to reduce neovascularization-related complications from 60% to 30%.
`Because only a few patients develop abnormal new blood vessels in the retina, not many need scatter
`photocoagulation treatment.
`
`Authors
`THANK YOU TO THE RETINA HEALTH SERIES AUTHORS
`Sophie J. Bakri, MD
`Audina Berrocal, MD
`Antonio Capone, Jr., MD
`Netan Choudhry, MD, FRCS-C
`Thomas Ciulla, MD, MBA
`Pravin U. Dugel, MD
`
`Anat Loewenstein, MD
`Mathew J. MacCumber, MD, PhD
`Maya Maloney, MD
`Timothy G. Murray, MD, MBA
`Hossein Nazari, MD
`Oded Ohana, MD, MBA
`
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 04 of 06
`
`

`

`Branch Retinal Vein Occlusion - Patients - The American Society of Retina Specialists
`
`Geoffrey G. Emerson, MD, PhD
`K. Bailey Freund, MD
`Roger A. Goldberg, MD, MBA
`Darin R. Goldman, MD
`Dilraj Grewal, MD
`Larry Halperin, MD
`Vi S. Hau, MD, PhD
`Suber S. Huang, MD, MBA
`G. Baker Hubbard, MD
`Mark S. Humayun, MD, PhD
`Talia R. Kaden, MD
`Peter K. Kaiser, MD
`M. Ali Khan, MD
`
`EDITOR
`John T. Thompson, MD
`
`SPANISH SERIES EDITORS
`J. Fernando Arevalo, MD, PhD
`Gabriela Lopezcarasa Hernandez, MD
`
`MEDICAL ILLUSTRATOR
`Tim Hengst
`
`Jonathan L. Prenner, MD
`Gilad Rabina, MD
`Carl D. Regillo, MD, FACS
`Naryan Sabherwal, MD
`Sherveen Salek, MD
`Andrew P. Schachat, MD
`Adrienne W. Scott, MD
`
`Michael Seider, MD
`Janet S. Sunness, MD
`Eduardo Uchiyama, MD
`Allen Z. Verne, MD
`Christina Y. Weng, MD, MBA
`Yoshihiro Yonekawa, MD
`
`Andres Lisker, MD
`Virgilio Morales-Canton, MD
`
`Copyright ©2016 The Foundation of the American Society of Retina Specialists. All rights reserved.
`
`
`
`
`
`
`
`
`
`
`
`
`
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 05 of 06
`
`

`

`Branch Retinal Vein Occlusion - Patients - The American Society of Retina Specialists
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`This resource is made possible in part through generous support from the Foundation
`of the American Society of Retina Specialists, Allergan, Genentech, Novartis, and
`Regeneron Pharmaceuticals.
`AMERICAN SOCIETY OF RETINA SPECIALISTS
`20 North Wacker Drive, Suite 2030, Chicago, Illinois 60606
`(312) 578-8760 phone
`
`
`
`© 2021 The American Society of Retina Specialists. All rights reserved.
`
`
`
`.
`
`
`
`
`
`.
`
`https://www.asrs.org/patients/retinal-diseases/24/branch-retinal-vein-occlusion[12/30/2021 3:45:23 PM]
`
`Exhibit 2150
`Page 06 of 06
`
`