Branch Retinal Vein Occlusion: Causes, Treatments, And What To Expect

Branch retinal vein occlusion (BRVO) is a sight-threatening condition affecting the delicate blood vessels within the eye. It occurs when a blockage develops in one of the smaller retinal veins, hindering the drainage of blood away from the light-sensitive layer of the eye, the retina. This disruption in your blood flow leads to a buildup of fluid in the macula, the central part of your retina that is responsible for sharp, central vision. BRVO is a variety of retinal vein occlusion (RVO), a broader term encompassing blockages in any retinal vein.

This comprehensive guide delves into BRVO, exploring its causes, available treatment options, what to expect during treatment procedures and the risk factors associated with the condition. By understanding BRVO, you can be empowered to recognise the potential signs and symptoms and seek timely medical attention to preserve your vision.

Understanding Branch Retinal Vein Occlusion

The retina, a thin layer of tissue that lines the back of the eyeball, plays a vital role in vision. It contains millions of light-sensitive cells that convert light into electrical signals that are transmitted to the brain, enabling us to see. Blood vessels within the retina nourish these cells and carry away waste products. Retinal veins are responsible for draining deoxygenated blood away from the retina.

In BRVO, a blockage develops in one of the smaller retinal veins. This obstruction disrupts blood flow, causing blood to accumulate within the retina. The buildup of blood can lead to:

• Macular Oedema: Fluid leakage from damaged blood vessels can accumulate in the macula, causing swelling and blurring of central vision.
• Retinal Neovascularisation: The body’s attempt to compensate for the blockage can lead to the growth of abnormal new blood vessels in the retina. These new vessels are weak and susceptible to bleeding, further compromising vision.
• Vitreous Haemorrhage: Bleeding into the vitreous cavity, the gel-like centre of the eye, can occur in some cases, causing vision floaters and reduced vision.

Unveiling The Spectrum Of Vision Loss In Branch Retinal Vein Occlusion (BRVO)

Branch Retinal Vein Occlusion (BRVO) disrupts the delicate balance of blood flow within the retina, potentially leading to a spectrum of vision loss. The severity and nature of this vision loss can change significantly from person to person, depending on several key factors. Understanding these factors empowers individuals to recognise the potential warning signs of BRVO and seek prompt medical attention.

• Location Matters: Blockages involving the macula, the central region for sharp vision, are more likely to cause significant central vision loss or a central scotoma (blind spot).
• Macular Oedema’s Impact: Fluid buildup in the macula (macular oedema) is a frequent complication that significantly worsens vision loss in BRVO.
• Retinal Damage: The extent of damage to retinal tissue caused by the blockage also plays a role. More extensive damage can translate to a greater decline in vision.
• A Spectrum Of Vision Changes: Individuals with BRVO may experience sudden blurring of central vision, distorted central vision, decreased peripheral vision, or floaters. Vision loss can develop suddenly or worsen gradually.

Unveiling The Underlying Causes Of Branch Retinal Vein Occlusion (BRVO)

While the exact cause of BRVO may not always be readily apparent, ophthalmologists have identified several significant contributing factors. Understanding these underlying risk elements empowers individuals to take preventive measures and recognise the importance of early intervention in the event of vision changes.

• High Cholesterol: High cholesterol levels contribute to plaque buildup in the arteries, which can eventually result in BRVO.
• High Blood Pressure: Uncontrolled high blood pressure adds stress to the blood vessels throughout the body, including those in the retina.
• Diabetic Retinopathy: Diabetes damages blood vessels, increasing the risk of blockages in the retina.
• Glaucoma: This condition increases pressure inside the eye, which can affect blood flow in the retinal veins.
• Hypercoagulability: Certain medical conditions or medications can increase the risk of blood clotting, making BRVO more likely.
• Age: BRVO is more common in people over 50.
• Smoking: Smoking ruins blood vessels and increases the probability of blood clotting.
• Obesity: Being overweight is related to an increased risk of BRVO.
• Sleep Apnoea: Obstructive sleep apnoea might be a major risk factor for BRVO.
• Family History: Having a close relative with BRVO can be a major cause of BRVO.

Types Of Branch Retinal Vein Occlusion: A Classification By Location

Branch retinal vein occlusion (BRVO) disrupts blood flow within the retinal veins, potentially leading to vision loss. While the core mechanism remains the same, the specific location of the blockage within the retinal venous network can influence the severity and presentation of the condition. Ophthalmologists categorise BRVO based on this anatomical feature, allowing for a more nuanced understanding of the disease and its potential impact.

Macular BRVO: A Direct Hit On Central Vision

The most common subtype of BRVO is macular BRVO. As the name suggests, this form of BRVO involves a blockage within a vein supplying the macula, the central area of the retina responsible for sharp, high-resolution vision. The macula plays a critical role in activities like reading, recognising faces, and perceiving fine details. Consequently, a blockage in a macular vein can significantly disrupt blood flow and compromise central vision. Individuals with macular BRVO may experience symptoms such as:

• Sudden blurring of central vision
• Difficulty reading or performing tasks requiring central focus
• Distorted central vision (seeing straight lines as wavy)
• A dark spot in the centre of their vision

The severity of vision loss in macular BRVO can depend on the extent of the blockage and the development of complications like macular oedema (fluid accumulation in the macula). Early diagnosis and treatment are crucial in minimising the vision loss associated with macular BRVO.

Non-Macular BRVO: Peripheral Blockage With Potentially Milder Vision Loss

In contrast to macular BRVO, non-macular BRVO refers to a blockage occurring in a retinal vein located outside the macula. Since these veins supply peripheral vision, the impact on central vision may be less severe. However, individuals with non-macular BRVO may experience:

• Blurring or dimming of vision in the affected peripheral field (lateral or temporal)
• Floaters (dark spots or squiggly lines) in their vision

The presence of these symptoms, particularly if they appear suddenly, warrants a visit to an ophthalmologist for a comprehensive evaluation. While non-macular BRVO may not cause immediate central vision loss, it’s important to note that complications like macular oedema can still develop and potentially affect central vision.

Treatments For Branch Retinal Vein Occlusion

Treatment for BRVO depends on the severity of the condition and the presence of complications like macular oedema (fluid buildup in the macula). There’s currently no cure for BRVO itself, but treatment aims to:

• Reduce Macular Oedema: This is often the primary focus. Anti-vascular endothelial growth factor (VEGF) treatment is a common approach. VEGF is a protein that increases abnormal blood vessel growth and fluid leakage. Medications injected directly into the eyes can help reduce macular oedema.
• End The Abnormal Growth Of Blood Vessels: In some cases, laser photocoagulation can be used to destroy abnormal blood vessels (retinal neovascularisation) that can develop as a complication of BRVO.
• Corticosteroid Injections: These medications injected into the eye can be helpful for severe macular oedema, but their use is so limited due to potential side effects.

Diagnosing Branch Retinal Vein Occlusion

An accurate diagnosis forms the cornerstone of effective treatment for Branch Retinal Vein Occlusion (BRVO). To achieve this, eye specialists employ a multi-pronged approach that combines various investigative techniques. Here are the essential components of diagnosing BRVO.

• Visual Acuity Test: This measures your ability to see letters or symbols at various distances.
• Dilated Eye Exam: Your ophthalmologist will use eye drops to widen your pupils for a better view of the retina and blood vessels.
• Optical Coherence Tomography (OCT): This imaging technique creates a cross-sectional image of your retina, allowing for the detection and measurement of macular oedema.
• Fluorescein Angiography: In some cases, a special dye is injected into a vein, and pictures of the eye are taken to assess blood flow patterns in the retina.

What To Expect During A Branch Retinal Vein Occlusion Procedure

Treatment procedures for BRVO are typically performed as outpatient procedures. Here’s a general idea of what to expect throughout the process, including the initial consultation:

Initial Consultation

Your ophthalmologist (eye specialist) will discuss your eye exams and diagnostics, medical history, current symptoms, and any medications you’re taking to determine your exact situation and the most suitable treatment.

Treatment Procedures

Based on the results of your initial session and diagnostic tests, your ophthalmologist will determine the most suitable approach for your specific case. Here’s an overview of the two main treatment procedures for BRVO:

• Anti-VEGF Injection: If treatment is deemed necessary, the most common approach is an anti-vascular endothelial growth factor (VEGF) injection. You’ll likely be awake during the procedure with numbing eye drops applied. A thin needle is inserted through the white part of your eye to inject the medication into the vitreous cavity, the gel-like substance in the centre of your eye. The procedure itself is usually quick and well-tolerated.
• Laser Treatment: In some cases, laser photocoagulation can be used to destroy abnormal new blood vessels (retinal neovascularisation) that can develop as a complication of BRVO. Similar to the injection, this is often done on an outpatient basis. The advanced laser beam is directed at specific areas of the retina to target these abnormal vessels. You may see flashing lights during the procedure, but it typically causes minimal discomfort.

Follow-Up Care

Following any procedure, your ophthalmologist will monitor your vision and the condition of your macula with regular checkups. The frequency of these follow-up appointments will depend on your specific situation and treatment response. During these visits, your vision will be reassessed, and your ophthalmologist may repeat imaging tests like OCT to monitor macular oedema and adjust your treatment plan as needed.

Living With Branch Retinal Vein Occlusion

While BRVO can be a sight-threatening condition, early diagnosis and treatment can assist in preventing vision loss and improving your visual outcome. Following your ophthalmologist’s recommended treatment plan and maintaining healthy lifestyle habits are crucial for managing BRVO. Here are some tips for living with BRVO:

• Adhere To Your Treatment Plan: Take medications as mentioned and attend follow-up appointments for monitoring.
• Maintain Good Blood Sugar Levels: If you suffer from diabetes, managing your blood sugar is essential to preventing further complications.
• Control Blood Pressure: Keeping your blood pressure within a healthy range is essential for overall eye health.
• Maintain A Healthy Weight: Losing fat if you’re overweight can help reduce your risk of BRVO complications.
• Quit Smoking: Smoking cessation is crucial for improving blood flow and lowering the risk of blood clots.
• Schedule Regular Eye Checkups: Regular eye examinations are essential to monitor your condition and detect any potential complications early on.

Frequently Asked Questions

What are the symptoms of BRVO?

The most common symptom of BRVO is sudden, undetectable vision loss, usually in one eye. You may also experience blurred vision, distorted vision, or a dark spot in your central vision.

Is BRVO a permanent condition?

BRVO itself is not a permanent condition, but the vision loss it causes can be permanent if left untreated. Early diagnosis and treatment are crucial to prevent vision loss and improve visual outcomes.

Can BRVO affect both eyes at the same time?

BRVO typically affects one eye at a time. However, it’s possible to develop BRVO in the other eye in the future.

What is the long-term prognosis for BRVO?

The long-term prognosis for BRVO depends on several factors, including:

• Severity Of The Initial Vision Loss: Those with more severe initial vision loss may have a lower chance of regaining full vision.
• Presence And Severity Of Macular Oedema: The degree of macular oedema and its response to treatment significantly impact visual outcomes.
• Underlying Health Conditions: Having uncontrolled medical conditions like diabetes or high blood pressure can worsen the prognosis.
• Treatment Adherence: Following the recommended treatment plan and attending regular follow-up appointments are crucial for optimal outcomes.

With early diagnosis and proper treatment, many people with BRVO experience significant improvement in their vision. However, some may experience persistent vision loss or require ongoing treatment to manage chronic macular oedema.

What are some potential complications of BRVO?

While treatment can effectively manage BRVO in most cases, some potential complications can arise:

• Chronic Macular Oedema: In some cases, macular oedema may persist despite treatment, leading to permanent vision loss.
• Retinal Neovascularisation: The abnormal growth of new blood vessels in the retina can lead to bleeding and further vision loss.
• Vitreous Haemorrhage: Bleeding into the vitreous cavity can cause vision floaters and sudden vision loss.
• Tractional Retinal Detachment: Scar tissue formation due to retinal neovascularisation can pull on the retina, causing a detachment and severe vision loss.

Early diagnosis and treatment are crucial to minimising the risk of these complications and preserving vision.

What’s the difference between central retinal vein occlusion and branch retinal vein occlusion?

While both central retinal vein occlusions (CRVOs) and branch retinal vein occlusions (BRVOs) involve blockages in retinal veins, the location and severity of the blockage can significantly differentiate these conditions. CRVO affects the central retinal vein, causing widespread disruption of blood flow, while BRVO affects a tributary vein, potentially leading to more localised consequences. This distinction is crucial for guiding treatment decisions and understanding the potential prognosis for vision outcomes.

Preserving Sight: A Final Word On BRVO Management

Branch retinal vein occlusion (BRVO) is a serious eye condition that requires prompt medical attention. By understanding the causes, symptoms, treatment options, and preventative measures, you can be empowered to manage your eye health and seek timely care if you experience any vision changes. Remember, early diagnosis and treatment are vital for preserving your vision and achieving the best possible outcomes following a BRVO diagnosis.

Contact Armadale Eye Clinic, Armadale, 3143, VIC, at (03) 9070 5753 to protect your vision and put an end to BRVO for good.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

Sources

Apostolopoulos, M., et al. “Late Complications in Branch Retinal Vein Occlusion.” International Ophtalmology/International Ophthalmology, vol. 19, no. 5, Jan. 1995, pp. 281–85. https://doi.org/10.1007/bf00130922.

Arnarsson, ÁRsaell, and Einar StefáNsson. Laser Treatment and the Mechanism of Edema Reduction in Branch Retinal Vein Occlusion. 1 Mar. 2000, iovs.arvojournals.org/article.aspx?articleid=2199887.

Caceres, Vanessa. “Conditions Treated With Laser Photocoagulation.” Verywell Health, 13 Sept. 2023, www.verywellhealth.com/laser-photocoagulation-5219365.

Cherney, Kristeen. “What to Expect During an Anti-VEGF Treatment.” Healthline, 8 Mar. 2022, www.healthline.com/health/eye-health/what-to-expect-during-an-anti-vegf-treatment.

Choi, Yu-Jin, et al. “Characteristics of Major and Macular Branch Retinal Vein Occlusion.” Scientific Reports, vol. 12, no. 1, Aug. 2022, https://doi.org/10.1038/s41598-022-18414-2.

“Risk Factors for Branch Retinal Vein Occlusion.” American Journal of Ophthalmology, vol. 116, no. 3, Sept. 1993, pp. 286–96. https://doi.org/10.1016/s0002-9394(14)71345-5.

“Treatment Options for Branch Retinal Vein Occlusion (BRVO) | Hull University Teaching Hospitals NHS Trust.” Hull University Teaching Hospitals NHS Trust, 9 Nov. 2023, www.hey.nhs.uk/patient-leaflet/treatment-options-branch-retinal-vein-occlusion-brvo-2.

Wu, Lihteh, MD. Branch Retinal Vein Occlusion (BRVO): Background, Pathophysiology, Epidemiology. emedicine.medscape.com/article/1223498-overview.

Yau, J. W. Y., et al., “Retinal Vein Occlusion: An Approach to Diagnosis, Systemic Risk Factors and Management.” Internal Medicine Journal, vol. 38, no. 12, Dec. 2008, pp. 904–10. https://doi.org/10.1111/j.1445-5994.2008.01720.x.

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