Central Retinal Artery Occlusion: Symptoms, Causes, Diagnosis, Prevention

Causes of Central retinal artery occlusion (CRAO)

CRAO is most commonly caused by a blood clot or embolus that blocks the central retinal artery. The embolus typically originates from the carotid artery or the heart and travels through the bloodstream, eventually lodging in the smaller vessels of the eye. Other less common causes include inflammation, compression of the artery, or vascular diseases affecting the blood vessels in the eye.

Certain health conditionings such as advanced age, hypertension (high blood pressure), diabetes, smoking, hyperlipidemia (high cholesterol), and a history of previous transient ischemic attacks (TIAs) or stroke can cause CRAO.

Treatment of CRAO

Central retinal artery occlusion treatment aims to restore blood flow in the retina and prevent further damage in vision loss. Although there is no treatment if the vision gets completely lost, a certain vision level can still be regained. It also depends on the issue's duration and the damage level in the retina. These are the best treatments to save the eyes from complete blindness:

• Ocular Massage: Digital massage of the globe of the affected eye may be performed to dislodge the embolus and improve blood flow. This technique should only be attempted by a qualified healthcare professional or ophthalmologist.
• Inhalation of Carbon Dioxide (Carbogen Therapy): Breathing in a mixture of carbon dioxide and oxygen, known as carbogen therapy, can help dilate blood vessels and improve oxygenation to the retina. This treatment is typically administered in a hospital or clinical setting.
• Medications:
  a. Acetazolamide: It helps reduce fluid buildup in the eye and may be prescribed to lower intraocular pressure and improve blood flow to the retina.
  b. Hyperbaric Oxygen Therapy (HBOT): HBOT involves breathing pure oxygen in a pressurized chamber, which can enhance oxygen delivery to tissues, including the retina.
• Thrombolysis: In certain instances, thrombolytic therapy may be considered to dissolve the blood clot causing the occlusion. Thrombolytic drugs, such as tissue plasminogen activator (TPA), can help restore blood flow.
• Intra-arterial Thrombolysis and Mechanical Thrombectomy: In more severe cases, when a visible clot causes the occlusion, specialized procedures like intra-arterial thrombolysis or mechanical thrombectomy may be attempted. These procedures remove the clot directly using catheters or devices, typically performed by interventional ophthalmologists or vascular specialists.

What are the complications?

The growth of abnormal blood vessels in the iris, retina, or angle are common complications. It can result in further vision loss or pain in the affected area of the eye. These irregular blood vessels cannot Ibe found in patients treated with tPA or hyperbaric oxygen. Therefore, these are treated with anti-VEGF agents or surgery if they increase to vitreous hemorrhage or uncontrolled glaucoma.

Prevention from CRAO

CRAO is generally connected to diabetes or heart problems, but they don't directly cause that. Yet, a safe and preventive step is to take care of your heart by doing these things:

• Maintain a healthy weight
• Consuming a healthy diet
• Daily exercises
• Stop smoking and alcohol
• Keep blood sugar levels at normal in case of diabetes