retinal vein occlusion

What is Retinal Vein Occlusion?

Retinal vein occlusion (RVO) is a common vascular disorder of the retina, affecting over 16 million people worldwide [1]. It is the second most common cause of blindness from retinal vascular disease after diabetic retinopathy [8].

There are two types of RVO: Branch Retinal Vein Occlusion (BRVO) and Central Retinal Vein Occlusion (CRVO). CRVO occurs when the main retinal vein becomes blocked, causing blood and fluid to spill out into the retina [14]. This can lead to swelling of the macula, affecting central vision, and eventually result in nerve cell death and vision loss.

Causes and Symptoms

The exact cause of RVO is unknown, but it is often associated with risk factors such as diabetes and high blood pressure [7]. Most patients develop CRVO in one eye, although some may experience varying degrees of vision loss [9].

Symptoms can include blurry vision, which may be temporary or permanent. In some cases, there are no symptoms at all.

Types of RVO

• Central Retinal Vein Occlusion (CRVO): The main retinal vein becomes blocked, causing blood and fluid to spill out into the retina.
• Branch Retinal Vein Occlusion (BRVO): Small blood vessels attached to the eye's main vein become blocked.

References

[1] Context result 6 [7] Context result 3 [8] Context result 9 [14] Context result 11

Common Signs and Symptoms of Retinal Vein Occlusion

Retinal vein occlusion (RVO) can cause a range of symptoms, which may vary in severity and duration. Here are some common signs and symptoms to look out for:

• Blurry vision or vision loss: This is the most common symptom of RVO, affecting one eye. The vision loss may start suddenly or develop gradually over hours or days.
• Vision distortion: Some people with RVO experience distorted vision, which can be described as "wavy" or "curved."
• Floaters: Small spots or threads in your visual field are known as floaters. They can be a sign of RVO.
• Painless vision loss: Unlike other eye conditions, RVO typically does not cause pain.
• Central retinal vein occlusion (CRVO): This is the most common type of RVO, affecting the main vein in the retina and causing sudden, painless vision loss.

Other Possible Symptoms

In some cases, people with RVO may experience:

• Macular edema: Swelling of the macula, which can cause distorted or blurry vision.
• Abnormal blood vessel formation: New blood vessels may grow on the surface of the retina, leading to further complications.
• Transient visual obscurations: Brief episodes of blurred or lost vision.

Important Note

It's essential to seek medical attention if you experience any of these symptoms, as early treatment can help prevent long-term damage and improve outcomes.

Diagnostic Tests for Retinal Vein Occlusion

Retinal vein occlusion (RVO) can be diagnosed through a combination of eye exams and imaging tests. Here are some of the diagnostic tests used to diagnose RVO:

• Eye Exam: An eye care specialist performs an eye exam to look for signs of RVO, such as retinal hemorrhage, thickened and twisted blood vessels, and macular edema.
• Fluorescein Angiography (FA): FA is a test that uses a fluorescent dye to highlight the blood vessels in the retina. It can help confirm the diagnosis of central retinal vein occlusion (CRVO) and show areas of nonperfusion or neovascularization.
• Optical Coherence Tomography (OCT) Scans: OCT scans measure retinal swelling (macular oedema) and can help diagnose RVO.
• Intraocular Pressure Measurement: Intraocular pressure measurement is used to check for glaucoma, which may be a concurrent condition with RVO.
• Visual Acuity Tests: Visual acuity tests are used to assess the patient's vision and determine the extent of any visual impairment.
• Electroretinography (ERG): ERG measures the electrical activity of the retina and can help differentiate between ischemic and nonischemic CRVO.

Additional Tests

In some cases, additional tests may be ordered to rule out other conditions or to assess for risk factors. These may include:

• Blood Pressure Measurement: Blood pressure measurement is used to check for hypertension, which is a risk factor for RVO.
• Erythrocyte Sedimentation Rate (ESR): ESR measures the rate at which red blood cells settle in a test tube and can be used to assess for inflammation or infection.

References

[1] Central retinal vein occlusion (CRVO) is an eye condition that affects the retina — the light-sensitive layer of tissue in the back of your eye. It happens when a blood clot blocks the main vein where blood flows out of the retina. [3]

[2] Fluorescein angiography is the most useful test for the evaluation of retinal capillary nonperfusion, posterior segment neovascularization, and macular edema. [5]

[3] All patients diagnosed with a central retinal vein occlusion should get the following tests and labs: Blood pressure. Erythrocyte sedimentation rate. [7]

[4] Diagnostic testing. Most often, BRVO is diagnosed through a combination of eye exams and imaging tests, including fluorescein angiography (FA), optical coherence tomography (OCT) scans, and intraocular pressure measurement. [11]

Note: The references are based on the information provided in the search results within the context section.

Treatment Options for Retinal Vein Occlusion

Retinal vein occlusion (RVO) can be treated with various medications, including anti-vascular endothelial growth factor (anti-VEGF) drugs and corticosteroids. These treatments aim to reduce inflammation, prevent further vision loss, and improve symptoms.

• Anti-VEGF Drugs: Injectable anti-VEGF drugs are the first choice for treating RVO. They target a protein that causes new, abnormal blood vessels to grow, which can lead to further vision loss ([2]). Examples of anti-VEGF drugs used in RVO treatment include Lucentis (Ranibizumab), Eylea (Aflibercept), and Avastin (Bevacizumab) ([8]).
• Corticosteroids: Corticosteroids, such as triamcinolone and dexamethasone, can be used to suppress inflammation in the eye. These medications are often injected directly into the vitreous gel that fills the center of the eye ([4], [6]). However, their use is typically reserved for patients who do not respond to anti-VEGF therapy.

Other Treatment Options

While medication is a primary treatment approach for RVO, other options may be considered in certain cases. These include:

• Focal Laser Treatment: This procedure involves using laser light to destroy abnormal blood vessels that are causing vision loss ([7]).
• Surgery: In some cases, surgery may be necessary to treat complications of RVO, such as retinal detachment or vitreous hemorrhage ([15]).

Important Considerations

It is essential to note that each patient's response to treatment can vary. Some individuals may experience significant improvement in vision, while others may not respond as well to therapy. Additionally, ongoing treatment may be necessary to manage symptoms and prevent further vision loss ([11]).

Retinal vein occlusion (RVO) can be challenging to diagnose, and it's essential to consider differential diagnoses to ensure accurate identification. Based on the search results, here are some key points to consider:

• Hypertensive retinopathy: This is an important differential diagnosis for RVO, particularly in patients with a history of hypertension (1). Hypertensive retinopathy can be distinguished from RVO by its characteristic features, such as retinal hemorrhages and vascular changes.
• Ocular ischemic syndrome: This condition can also mimic the symptoms of RVO, especially in cases where there is significant retinal ischemia (3).
• Diabetic retinopathy: Diabetic retinopathy is a common cause of vision loss and can be confused with RVO, particularly in patients with diabetes (4). However, diabetic retinopathy typically presents bilaterally, whereas RVO is usually unilateral.
• Central Retinal Vein Occlusion (CRVO): CRVO is a type of RVO that involves occlusion of the central retinal vein. It's essential to differentiate CRVO from other conditions, such as ocular ischemic syndrome and diabetic retinopathy, using clinical features like retinal hemorrhages and vascular changes (6).
• Macular edema: Macular edema can be a complication of RVO and may require additional diagnostic workup, including fluorescein angiography to determine the degree of retinal ischemia (3).

To summarize:

• Hypertensive retinopathy, ocular ischemic syndrome, diabetic retinopathy, CRVO, and macular edema are all important differential diagnoses for RVO.
• Accurate diagnosis requires consideration of clinical features, patient history, and additional diagnostic tests like fluorescein angiography.

References: [1] [2] [3] [4] [6]