Branch Vein OcclusionsBranch Vein Occlusions(BRVOs)(BRVOs)

Fritz Allen MDFritz Allen MD

May 22May 22ndnd 2011 2011

BackgroundBackground

This presentation will be addressing This presentation will be addressing exclusively the branch retinal vein occlusions exclusively the branch retinal vein occlusions (BRVOs). The Central retinal vein occlusions (BRVOs). The Central retinal vein occlusions and Hemiretinal vein occlusions have a and Hemiretinal vein occlusions have a different natural history and complication ratedifferent natural history and complication rate

PathophysiologyPathophysiology

The artery and the vein share a common The artery and the vein share a common adventitial sheath. Arterial compression of the adventitial sheath. Arterial compression of the vein is believe to be the main cause of BRVO. vein is believe to be the main cause of BRVO. Compression of the vein may lead to turbulent Compression of the vein may lead to turbulent in the vein causing intravascular thrombus in the vein causing intravascular thrombus formation with his cascade of retinal ischemia, formation with his cascade of retinal ischemia, VEGF production, macular edema and retinal VEGF production, macular edema and retinal neovascularizationneovascularization

EpidemiologyEpidemiology

**Frequency USA: prevalence 0.9%USA: prevalence 0.9% International: prevalence 1.1-1.3%International: prevalence 1.1-1.3%**Mortality/MorbidityMortality/Morbidity BRVO usually associated with higher BRVO usually associated with higher

cardiovascular mortalitycardiovascular mortality**No race or sex predilectionNo race or sex predilection**AgeAge: patient in their 5: patient in their 5thth and 6 and 6thth decades decades

Clinical PresentationClinical Presentation

**HistoryHistory : :

The Eye Disease Case-Control Study findings:The Eye Disease Case-Control Study findings: 1- Systemic Hypertension is a risk factor for BRVO1- Systemic Hypertension is a risk factor for BRVO 2- DM and POAG are not risk factors for BRVO2- DM and POAG are not risk factors for BRVO 3- Moderate alcohol consumption reduces the risk of 3- Moderate alcohol consumption reduces the risk of

BRVOBRVO Chief complaint: Chief complaint: Sudden painless decrease vision in the affected eye Sudden painless decrease vision in the affected eye Scotoma Scotoma

Clinical Presentation Clinical Presentation PhysicalPhysical *In 1877, Leber first described the BRVO *In 1877, Leber first described the BRVO

ophthalmoscopically: During the acute phase, ophthalmoscopically: During the acute phase, Intraretinal hemorrhages (usually flame shaped), Intraretinal hemorrhages (usually flame shaped), Retinal edema, Cotton-wool spots. Horizontal raphe Retinal edema, Cotton-wool spots. Horizontal raphe respected.respected.

*During the chronic phase, hemorrhages may be *During the chronic phase, hemorrhages may be absent , macular edema may be present and absent , macular edema may be present and telangiectatic vessels usually seen.telangiectatic vessels usually seen.

*Exudative Retinal Detachment (rare)*Exudative Retinal Detachment (rare)

Clinical PresentationClinical Presentation

PhysicalPhysical

*In eyes with large area of nonperfusion, *In eyes with large area of nonperfusion, retinal neovascularization may be seen leading retinal neovascularization may be seen leading to : vitreous hemorrhage , tractional retinal to : vitreous hemorrhage , tractional retinal detachments. Neovascular Glaucoma and detachments. Neovascular Glaucoma and NVD are rare in BRVONVD are rare in BRVO

Clinical presentationClinical presentation

CausesCauses

*Most cases of BRVO are due to idiopathic factors *Most cases of BRVO are due to idiopathic factors (AV crossing)(AV crossing)

*Some inflammatory reported associated with *Some inflammatory reported associated with BRVO: Sarcoidosis, Lyme disease, Serpiginous BRVO: Sarcoidosis, Lyme disease, Serpiginous Choroiditis.Choroiditis.

*Arterial Hypertension + Hypercholesterolemia *Arterial Hypertension + Hypercholesterolemia leading to Atherosclerosis/Atherogenesisleading to Atherosclerosis/Atherogenesis

Clinical PresentationClinical Presentation CausesCauses *Thrombophilic conditions may be involved*Thrombophilic conditions may be involved - Protein S deficiency- Protein S deficiency - Protein C deficiency- Protein C deficiency - Resistance to activated Protein C - Resistance to activated Protein C (factor V Leiden)(factor V Leiden) - Antithrombin III deficiency- Antithrombin III deficiency - Antiphospholipid antibody syndrome- Antiphospholipid antibody syndrome - Lupus Erythematosus- Lupus Erythematosus - Gammopathies- Gammopathies

Differential DiagnosesDifferential Diagnoses

DifferentialsDifferentials

* Central Retinal vein Occlusion* Central Retinal vein Occlusion

* Hypertension* Hypertension

* Macular Edema (diabetic)* Macular Edema (diabetic)

* Diabetic Retinopathy ,Background and * Diabetic Retinopathy ,Background and ProliferativeProliferative

WorkupWorkup Laboratory StudiesLaboratory Studies The authors of the Branch Vein Occlusion Study (BVOS) have The authors of the Branch Vein Occlusion Study (BVOS) have

recommended against extensive testing in patient with typical recommended against extensive testing in patient with typical BRVOBRVO

In atypical cases (bilateral, young patient and history of In atypical cases (bilateral, young patient and history of thromboembolism)thromboembolism)

-PT, aPTT-PT, aPTT -Protein C, protein S, factor V Leiden, antithrombin III-Protein C, protein S, factor V Leiden, antithrombin III -Homocystein-Homocystein -ANA, lupus anticoagulant, anticardiolipin-ANA, lupus anticoagulant, anticardiolipin -Serum protein electrophoresis (SPEP)-Serum protein electrophoresis (SPEP)

WorkupWorkup

Imaging StudiesImaging Studies * Fluorescein Angiography* Fluorescein Angiography IVFA is done as soon as the hemorrhages IVFA is done as soon as the hemorrhages

have cleared, usually 3 months after the eventhave cleared, usually 3 months after the event The purpose is to determine the cause of The purpose is to determine the cause of

vision loss (macular edema vs macular vision loss (macular edema vs macular ischemia) in order to plan treatment.ischemia) in order to plan treatment.

*OCT can be useful in the follow up of *OCT can be useful in the follow up of macular edema secondary to BRVO.macular edema secondary to BRVO.

WorkupWorkup

Histologic FindingsHistologic Findings

confirmed the importance of AV crossings in confirmed the importance of AV crossings in the pathogenesis of BRVOthe pathogenesis of BRVO

Inner retinal ischemic areas have been Inner retinal ischemic areas have been described distal to occlusion site described distal to occlusion site

Arteriolar sclerosis have been reportedArteriolar sclerosis have been reported

Intravascular thrombus at site of occlusion Intravascular thrombus at site of occlusion

Treatment & Management Treatment & Management

Medical CareMedical Care -Medical treatment of BRVO is not effective .-Medical treatment of BRVO is not effective . Anticoagulants, fibrinolytic agents, clofibrate Anticoagulants, fibrinolytic agents, clofibrate

capsule, Carbogen inhalation have been tried capsule, Carbogen inhalation have been tried without success without success

-Intravitreal injection of Triamcinolone (4mg?)-Intravitreal injection of Triamcinolone (4mg?) -Retrobulbar injection of Triamcinolone -Retrobulbar injection of Triamcinolone

(20mg). Complications: cataract, glaucoma, (20mg). Complications: cataract, glaucoma, endophthalmitis.endophthalmitis.

Treatment &Management Treatment &Management

Medical CareMedical Care

-Intravitreal injection of VEGF inhibitors -Intravitreal injection of VEGF inhibitors Bevacizumab (Avastin) 1.25-2.5mg , effective Bevacizumab (Avastin) 1.25-2.5mg , effective in reducing macular edema and improving in reducing macular edema and improving visual acuityvisual acuity

Treatment & Management Treatment & Management

Surgical careSurgical care * Macular grid laser photocoagulation* Macular grid laser photocoagulation remained the standard treatment for macular edema remained the standard treatment for macular edema

from BRVO after 3 months observation and only for from BRVO after 3 months observation and only for perfused maculas. After 3 years of follow up 63% of perfused maculas. After 3 years of follow up 63% of treated eyes improve by 2 lines or more vs 36% of treated eyes improve by 2 lines or more vs 36% of control eyes.control eyes.

* Scatter photocoagulation* Scatter photocoagulation reduces the prevalence of neovascularization by 50% reduces the prevalence of neovascularization by 50%

(from 40% to 20%). (from 40% to 20%).

Treatment & Management Treatment & Management

Surgical CareSurgical Care

* Laser-induced chorioretinal anastomosis* Laser-induced chorioretinal anastomosis

tries to create a communication between tries to create a communication between occluded vessel and choroid . Technique is occluded vessel and choroid . Technique is unreliable (30-50% success rate) and potential unreliable (30-50% success rate) and potential complications include retinal detachment and complications include retinal detachment and vitreous hemorrhage.vitreous hemorrhage.

Treatment & Management Treatment & Management

Surgical CareSurgical Care

*Vitrectomy and arteriovenous decompression*Vitrectomy and arteriovenous decompression

claimed to improve macular edema and claimed to improve macular edema and macular perfusion macular perfusion

* Vitrectomy and posterior hyaloid separation * Vitrectomy and posterior hyaloid separation improve visual acuityimprove visual acuity

Treatment & Management Treatment & Management

ConsultationsConsultations

*Consult a vitreoretinal specialist if *Consult a vitreoretinal specialist if complications arisecomplications arise

*In atypical cases when thrombophilic *In atypical cases when thrombophilic conditions are suspected, consultation with an conditions are suspected, consultation with an hematologist is recommended.hematologist is recommended.

MedicationMedication

* Medication Summary* Medication Summary The goals of pharmacotherapy are to reduce The goals of pharmacotherapy are to reduce

morbidity and prevent complicationsmorbidity and prevent complications*Corticosteroids: have potent anti-inflammatory and *Corticosteroids: have potent anti-inflammatory and

antipermeability propertiesantipermeability properties - Triamcinolone (Kenalog-40)- Triamcinolone (Kenalog-40)*Vascular Endothelial Growth Factor (VEGF) inhibitors*Vascular Endothelial Growth Factor (VEGF) inhibitors - Bevacizumab (Avastin) inhibits angiogenesis- Bevacizumab (Avastin) inhibits angiogenesis - Ranibizumab (Lucentis)- Ranibizumab (Lucentis)

Follow up careFollow up care

Monitor the development of possible complications : Monitor the development of possible complications : IVFA to guide further therapyIVFA to guide further therapy

ComplicationsComplications - Macular edema - Macular edema - Retinal neovascularization- Retinal neovascularization *Vitreous hemorrhage*Vitreous hemorrhage *Tractional retinal detachment *Tractional retinal detachment *Rubeosis iridis*Rubeosis iridis - Epiretinal membrane- Epiretinal membrane

PrognosisPrognosis

Analysis of several series indicates that 53% Analysis of several series indicates that 53% of eyes obtain 20/40 or better visual acuity, of eyes obtain 20/40 or better visual acuity, 25% have between 20/50 and 20/100, and 25% have between 20/50 and 20/100, and 22% have visual acuity of 20/200 or worse.22% have visual acuity of 20/200 or worse.

The more distal the occlusion is from the optic The more distal the occlusion is from the optic disc, the better the visual prognosis.disc, the better the visual prognosis.

Patient EducationPatient Education

* Instruct patient about reducing risks : * Instruct patient about reducing risks :

Keep good Blood pressure control and Keep good Blood pressure control and maintain good Cholesterol level.maintain good Cholesterol level.

* Instruct patient with BRVO to seek attention if * Instruct patient with BRVO to seek attention if further vision loss occurs during follow-up.further vision loss occurs during follow-up.

Bibliography/AcknowledgementBibliography/Acknowledgement

Lihteh Wu, MD ,Costa RicaLihteh Wu, MD ,Costa Rica Teodoro Evans, MD ,CanadaTeodoro Evans, MD ,Canada Hampton Roy Sr, MD ,USAHampton Roy Sr, MD ,USA