WHAT WE TREAT
Central Retinal Artery Occlusion
CRAO is a sudden blockage of the main artery supplying blood to the retina, causing rapid and severe vision loss.
About Central Retinal Artery Occlusion
Overview
The retina is a thin, light-sensitive layer of tissue that lines the back of the eye—similar to wallpaper inside a room. When light enters the eye, it passes through the cornea and lens before reaching the retina. The retina converts this light into electrical signals that are sent through the optic nerve to the brain, where they are processed into the images we see. Because the retina is essential for vision, any interruption in its function can result in serious and sometimes permanent vision loss.
A Central Retinal Artery Occlusion (CRAO) occurs when the main artery supplying the retina becomes blocked, cutting off blood flow and oxygen. This event usually happens suddenly and without warning, leading to severe and often permanent vision loss in the affected eye. The degree of vision loss depends on how completely the artery is blocked and how quickly blood flow can be restored. Unfortunately, because the retina can sustain irreversible damage within minutes, there is rarely an effective treatment to restore lost vision once a CRAO has occurred.
Causes
The most common cause of a CRAO is an embolus—a small particle such as a cholesterol plaque or blood clot—that travels through the bloodstream and becomes lodged in the retinal artery. Because emboli often originate from other parts of the body, such as the carotid arteries or heart, the presence of a CRAO may indicate an increased risk of other serious vascular events, including stroke.
Following diagnosis, a comprehensive medical evaluation by your primary care physician is strongly recommended to identify possible embolic sources or systemic conditions that contributed to the blockage. The primary goal of this evaluation is prevention of future events, not restoration of vision. Less common causes include inflammation of the blood vessels (vasculitis) or abnormal blood clotting.
Treatment Options From LRR
Treatments
Although vision loss from CRAO is typically permanent, follow-up care remains essential. Regular examinations allow your retina specialist to monitor for these complications and initiate timely treatment to preserve the overall health of the eye.
Even though current treatments cannot reverse the vision loss caused by CRAO, ongoing monitoring and systemic medical management can help prevent further vascular events and protect the health of your other eye.
More To Know
Risk Factors
Common risk factors include:
- High blood pressure (hypertension)
- Diabetes mellitus
- High cholesterol (hyperlipidemia)
- Smoking
- Heart disease or atherosclerosis
Complications and Follow-Up Care
Eyes affected by CRAO are at risk for secondary complications, which can develop weeks tomonths after the initial event. These may include:
- Neovascularization (growth of abnormal new blood vessels)
- Neovascular glaucoma (elevated eye pressure due to new vessel growth)
- Ocular ischemia (continued poor retinal blood flow)
How Blood Reaches the Retina
The retina receives its blood supply through a small but vital vessel called the central retinal artery. This artery travels through the optic nerve and enters the retina, where it branches into progressively smaller arterioles and capillaries—much like a tree trunk dividing into smaller branches. These arteries deliver oxygen-rich blood to the retina, while a parallel system of veins collects and drains blood through the central retinal vein. Many retinal conditions, including artery or vein blockages, result from problems in this delicate vascular system.
Prepare For Your Visit
If you already have an appointment made, we look forward to providing your care! If you need an appointment or have questions, please reach out to the Lakes Region Retina care team.
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