Central retinal artery occlusion

Central retinal artery occlusion (CRAO) is a medical condition where the central retinal artery becomes blocked, leading to a sudden and severe loss of vision in the affected eye. This condition is considered an ocular emergency and requires immediate medical attention to prevent permanent vision loss.

Pathophysiology

The central retinal artery is a branch of the ophthalmic artery, which supplies oxygenated blood to the retina. When this artery becomes occluded, the blood supply to the retina is interrupted, leading to ischemia and potential infarction of retinal tissue. The most common cause of CRAO is an embolism, which can originate from the carotid arteries or the heart. Other causes include thrombosis, vasculitis, and hypercoagulable states.

Symptoms

The primary symptom of CRAO is a sudden, painless loss of vision in one eye. Patients may describe the vision loss as a "curtain" descending over their field of vision. In some cases, there may be a preceding history of amaurosis fugax, which is a temporary loss of vision due to transient ischemia.

Diagnosis

Diagnosis of CRAO is typically made through a combination of patient history, clinical examination, and diagnostic tests. An ophthalmoscope examination may reveal a pale retina with a cherry-red spot at the fovea. Additional tests may include fluorescein angiography, optical coherence tomography (OCT), and visual field testing.

Treatment

Immediate treatment is crucial to improve the chances of visual recovery. Initial management may include ocular massage, anterior chamber paracentesis, and administration of hyperbaric oxygen therapy. Long-term management focuses on addressing the underlying cause of the occlusion, such as controlling hypertension, diabetes mellitus, and hyperlipidemia.

Prognosis

The prognosis for CRAO is generally poor, with many patients experiencing permanent vision loss. However, early intervention and treatment of underlying conditions can improve outcomes. Regular follow-up with an ophthalmologist and a cardiologist is recommended to monitor and manage risk factors.

Prevention

Preventive measures include managing cardiovascular risk factors such as hypertension, diabetes, and hyperlipidemia. Patients with a history of transient ischemic attacks (TIAs) or other embolic events should be evaluated and treated to reduce the risk of CRAO.

See also

• Retinal vein occlusion
• Amaurosis fugax
• Ophthalmic artery
• Ischemic optic neuropathy