Understanding Retinal Vein Occlusion: Causes, Symptoms, and Treatments

Retinal vein occlusion (RVO) is a condition affecting the retina, the thin layer of tissue at the back of the eye that helps us process light into images. Let’s explore RVO, including its types, symptoms, causes, and available treatment options.

What Is Retinal Vein Occlusion?

In RVO, a vein in the retina becomes blocked, typically by a blood clot. The blocked vein can’t properly drain blood, which may result in a buildup of fluid or even bleeding in the retina. This condition has similarities with retinal artery occlusion (RAO), commonly called an “eye stroke,” although RVO is more common. RVO can lead to complications such as swelling of the retina, abnormal blood vessel growth, and increased eye pressure, which may result in a type of glaucoma known as neovascular glaucoma.

Types of Retinal Vein Occlusion

There are two primary types of RVO, depending on where the blockage occurs in the retinal vein system:

Central Retinal Vein Occlusion (CRVO): This type involves a blockage in the retina’s central vein, which can cause sudden and sometimes severe vision loss. Common early symptoms include the appearance of “floaters”—small spots or lines that seem to drift across your field of vision. CRVO can happen quickly or gradually over days and, in more severe cases, may lead to pain from increased pressure in the eye.
Branch Retinal Vein Occlusion (BRVO) occurs when a smaller branch of the central retinal vein becomes blocked. Symptoms of BRVO are similar to those of CRVO, with vision changes that may develop over several hours or days. Blurred vision or vision loss in a portion of the eye is common, and floaters may also appear.

Causes and Risk Factors of Retinal Vein Occlusion

A blood clot often causes RVO, but it can also occur when a nearby artery compresses the vein, leading to narrowed blood flow. This can happen if the artery’s walls harden due to atherosclerosis (buildup of fatty deposits).

Several risk factors increase the likelihood of developing RVO:

Chronic conditions: High blood pressure, diabetes, and other vascular-related conditions can increase the risk.
Lifestyle factors: Smoking and being overweight contribute to RVO risk.
Age: RVO is more common in older adults.
Other health conditions: Blood disorders like lymphoma, leukaemia, and multiple myeloma, as well as glaucoma, can also elevate the risk.

Symptoms

Symptoms of RVO vary depending on the severity of the blockage and the type of RVO. In some cases, individuals may not experience noticeable symptoms and may only discover the condition during a routine eye exam. However, typical symptoms include:

Blurry or missing vision in parts or all of the affected eye
Eye floaters
Pain and pressure in the eye (mainly with CRVO)

If you experience any of these symptoms, seeing a healthcare provider is essential, as early diagnosis can help manage and reduce complications.

Diagnosing Retinal Vein Occlusion

To diagnose RVO, an eye doctor will typically dilate your pupils and examine your retina with an ophthalmoscope. Additional imaging tests, such as fluorescein angiography, optical coherence tomography (OCT), or fundus photography, may be performed to capture detailed images of the retina’s blood vessels and assess any swelling, blood leakage, or abnormal vessel growth.

Treatment Options for Retinal Vein Occlusion

While there is no direct cure for RVO, several treatments are available to manage its symptoms and complications:

Anti-VEGF Injections: These are commonly the first line of treatment, targeting proteins that promote abnormal blood vessel growth. Medications like aflibercept and ranibizumab reduce swelling and prevent further vision loss. Most patients require repeat injections over a period of time.
Steroid Injections: For some patients, steroid injections may help alleviate swelling, especially if anti-VEGF treatments are ineffective. However, steroid shots are usually a secondary option due to the risk of increased eye pressure.
Laser Therapy: In some cases, focal laser photocoagulation is used to seal leaking blood vessels near the macula. Panretinal photocoagulation (PRP) can also treat abnormal blood vessel growth by creating tiny burns in the retina.
Vitrectomy Surgery: If severe bleeding or retinal detachment occurs, vitrectomy surgery may be necessary. This procedure involves removing the eye’s gel-like vitreous humour and replacing it with a clear solution, gas bubble, or silicone oil.

Preventing Retinal Vein Occlusion

While it’s not always possible to prevent RVO, managing risk factors can reduce its likelihood. This includes controlling blood pressure, cholesterol, and blood sugar levels, especially if you have diabetes. Avoiding smoking, maintaining a healthy weight, and protecting the eyes from potential injuries are also beneficial. For women taking hormonal birth control, it may be worthwhile to discuss any concerns with a healthcare provider, as these medications can occasionally contribute to RVO.

Looking Ahead

Though retinal vein occlusion can be a severe condition, advances in treatment continue to provide practical ways to manage symptoms and protect vision. By being proactive with eye health, especially for those with existing risk factors, you can reduce the impact of RVO on your sight and overall quality of life.

Sources:

Central Retinal Vein Occlusion Treatment

https://www.indiamart.com/proddetail/central-retinal-vein-occlusion-treatment-5786872448.html

Retinal Vein Occlusions: Types, Causes & Symptoms

https://www.shinagawa.com.sg/news-resources/retinal-vein-occlusions-types-causes-symptoms

What Is a Retinal Vein Occlusion?

https://www.aao.org/eye-health/diseases/retinal-vein-occlusion-3