Retinal Vein Occlusion (RVO)

What is the Retina?
The retina is a light-sensitive layer located at the back of the eye. It captures visual stimuli and converts them into electrical signals, which are then transmitted through the optic nerve to the brain for interpretation.

What are Retinal Veins?
Retinal veins are small blood vessels that transport deoxygenated blood from the retina to the heart. The central retinal vein runs through the optic nerve, while smaller veins within the retina drain blood into the central retinal vein for circulation.

What is Retinal Vein Occlusion (RVO)?
Retinal vein occlusion is a condition in which a vein in the retina becomes blocked, disrupting the normal blood flow and depriving the affected area of oxygen and nutrients. This blockage can cause leakage of blood and excess fluid into the retina, leading to macular edema. The macula, located in the central part of the retina, is responsible for sharp, central vision.

RVO can affect individuals of any gender, but it is most commonly observed in those aged 50 and older, particularly in middle-aged and elderly individuals.

How Does Retinal Vein Occlusion Impact Vision?
The most common cause of vision impairment in retinal vein occlusion is macular edema. Other contributing factors include retinal hemorrhages (blood clots) and macular ischemia (reduced blood flow to the macula). These conditions can result in blurry vision and distorted images. In some cases, both eyes may be affected simultaneously.

What Are the Consequences of Retinal Vein Occlusion (RVO)?
Retinal vein occlusion can result in abnormal blood vessel growth in the anterior segment of the eye, leading to secondary glaucoma (increased intraocular pressure). This may cause localized vision loss and, in severe cases, can lead to blindness. RVO is the second most common cause of blindness due to retinal vascular disease.

What Are the Types of Retinal Vein Occlusion?
Retinal vein occlusion is classified based on the location of the blockage, and is primarily categorized into two types:

1. Central Retinal Vein Occlusion (CRVO)

The main vein in the back of they eye (central retinal vein) becomes blocked.

2. Branch Retinal Vein Occlusion (BRVO)

Blockage in a branch of the central retinal vein, leading to localized retinal swelling and bleeding.

Risk Factors for Retinal Vein Occlusion (RVO)

Retinal vein occlusion is more prevalent in individuals aged 50 and older. Other significant risk factors include: Hypertension, Diabetes, Hyperlipidemia, Glaucoma, Atherosclerosis, Smoking, and Obesity.

Diagnosis of Retinal Vein Occlusion (RVO)

Diagnosing retinal vein occlusion involves a comprehensive eye examination, including:

1. Visual Acuity Test: Assesses clarity of vision at different distances.

2. Optical Coherence Tomography (OCT): This technique uses long-wavelength light to measure retinal thickness. OCT can display high-resolution cross-sections of the retina, detecting and measuring fluid accumulation, and monitoring disease progression

3. Fluorescein Angiography: Involves the injection of fluorescein dye to visualize retinal blood flow, identify areas of blockage, and detect leakage from damaged blood vessels.

4. Fundus Examination: A dilated eye exam to inspect the retina for hemorrhages, edema, and signs of retinal vein blockage.

An ophthalmologist may perform a visual field test to assess your peripheral vision and use a fundus examination to evaluate the extent of vascular blockage.

Treatment Options for Retinal Vein Occlusion (RVO) with Macular Edema

How is Retinal Vein Occlusion (RVO) treated?

Some patients with retinal vein occlusion may experience partial vision recovery even without treatment, although it is rare for vision to return to normal levels. Studies show that patients who receive treatment for RVO experience significant improvement in vision compared to those who do not receive treatment

1. Focal Laser Photocoagulation: Focal laser therapy targets areas of retinal leakage near the macula using precise laser burns. This reduces fluid buildup, stabilizes the retina, and helps slow vision loss in retinal vein occlusion (RVO) cases. It's most effective for localized edema and when applied early.

2. Intravitreal Injections: Medications are injected into the eye to reduce macular edema, inhibit leakage, and prevent abnormal blood vessel growth, helping to preserve vision. Corticosteroid implants can also treat retinal vein occlusion

Intravitreal Injection Therapy

Blocks VEGF to prevent abnormal blood vessel growth and reduce leakage.

Procedure:

  • Eye is sterilized and anesthetized.

  • Anti-VEGF medication is injected into the vitreous.

  • Periodic injections until vision stabilizes.

How to Prevent Retinal Vein Occlusion (RVO)

RVO is often related to general vascular health. Preventing other vascular conditions, such as coronary artery disease, can help reduce the risk of RVO.

  • Control blood sugar

  • Manage blood pressure

  • Maintain a healthy lifestyle