Understanding Retinal Vascular Occlusions

Retinal vein occlusion, more common than its arterial counterpart, occurs when a vein that drains blood from the retina becomes blocked. This blockage can cause blood to back up, leading to leakage, swelling (especially in the central part called the macula), and sometimes bleeding. There are several forms of RVO, including:

• Central Retinal Vein Occlusion (CRVO): This involves a blockage in the main retinal vein and can result in widespread retinal damage.
• Branch Retinal Vein Occlusion (BRVO): When one of the smaller branch veins is blocked, resulting in vision issues that may affect only a portion of the retina.
• Hemiretinal Vein Occlusion: This type affects roughly half of the retinal field and is less common but still significant.

Even when RVO develops gradually, the impact on your vision can be significant, and early detection is key to managing the condition effectively.

Retinal artery occlusion is less common but can be more severe because the arteries carry oxygen-rich blood to the retina. RAO typically presents with sudden, painless vision loss, and patients may describe a “black curtain” descending over their field of vision. There are several subtypes, including:

• Central Retinal Artery Occlusion (CRAO): A blockage in the primary artery supplying the retina, which often results in significant vision loss if not treated immediately.
• Branch Retinal Artery Occlusion (BRAO): Involves a blockage in one of the smaller branch arteries, with varying degrees of vision impairment, often with some ability for partial recovery.
• Ophthalmic Artery Occlusion (OAO): A rare occurrence that affects the main artery supplying the eye and can produce severe vision deficits.

Because the retina is highly sensitive to oxygen deprivation, any interruption in its arterial supply is treated as a medical emergency by our retina specialist.

If not managed properly, retinal vascular occlusions can lead to several serious complications. It is important to understand these potential issues so that we can work together to monitor your condition closely.

• Macular Edema: The buildup of fluid in the macula leads to swelling, causing blurred or distorted central vision.
• Neovascularization: This involves the growth of new, abnormal blood vessels, which can bleed or lead to further complications such as increased eye pressure.
• Vitreous Hemorrhage: Bleeding within the gel-like substance of the eye may cloud your vision and complicate the medical picture.
• Neovascular Glaucoma: An increase in eye pressure due to abnormal vascular growth can be painful and further jeopardize vision.
• Retinal Detachment: In severe cases, parts of the retina may separate from the underlying tissue, leading to irreversible vision loss.

Timely intervention, careful monitoring, and adherence to treatment plans can significantly reduce the risk of these complications and help maintain your vision.