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Central Retinal Artery Occlusion

Disease Details

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Description: Central retinal artery occlusion is a condition where the main artery supplying blood to the retina becomes blocked, leading to sudden, painless vision loss in one eye.
Type: Central retinal artery occlusion (CRAO) is not typically classified under genetic diseases, and it does not have a specific type of genetic transmission. It is primarily an ophthalmologic emergency often caused by embolism or thrombosis leading to sudden, painless vision loss in one eye. Risk factors include cardiovascular diseases such as hypertension, diabetes mellitus, and atherosclerosis.
Signs And Symptoms: Central retinal artery occlusion is characterized by painless, acute vision loss in one eye. Upon fundoscopic exam, one would expect to find: cherry-red spot (90%) (a morphologic description in which the normally red background of the choroid is sharply outlined by the swollen opaque retina in the central retina), retinal opacity in the posterior pole (58%), pallor (39%), retinal arterial attenuation (32%), and optic disk edema (22%). During later stages of onset, one may also find plaques, emboli, and optic atrophy.
Prognosis: The artery can re-canalize over time and the edema can clear. However, optic atrophy leads to permanent loss of vision. Irreversible damage to neural tissue can occur after approximately 15 minutes of complete blockage to the central retinal artery, but this time may vary between people. Two thirds of people experience 20/400 vision while only one in six will experience 20/40 vision or better.
Onset: Central retinal artery occlusion (CRAO) typically has a sudden onset. It often manifests as sudden, painless loss of vision in one eye. The vision loss can occur within seconds to minutes and is usually described as severe.
Prevalence: The prevalence of central retinal artery occlusion (CRAO) is relatively rare, estimated to be between 1 and 10 cases per 100,000 individuals. The condition primarily affects older adults, particularly those aged 60 and above.
Epidemiology: The incidence of CRAO is approximately 1 in 100,000 people in the general population. Risk factors for CRAO include the following: being over 50 years of age, male gender, smoking, hypertension, tranexamic acid, diabetes mellitus, dyslipidemia, angina, valvular disease, transient hemiparesis, cancer, hypercoagulable blood conditions, lupus, or a family history of cerebrovascular or cardiovascular issues. Additional risk factors include endocarditis, atrial myxoma, inflammatory diseases of the blood vessels, and predisposition to forming blood clots.
Intractability: Central retinal artery occlusion (CRAO) is considered a medical emergency due to its potential to cause sudden and irreversible vision loss. While it is not necessarily "intractable" in terms of being unmanageable, the prognosis for visual recovery is generally poor, especially if treatment is not initiated promptly. Rapid intervention within a few hours of symptom onset may improve outcomes, but once significant damage has occurred, recovery is limited.
Disease Severity: Central retinal artery occlusion (CRAO) is considered a medical emergency and is often classified as a severe condition. It can lead to sudden and painless loss of vision in the affected eye. The severity is largely determined by the extent and duration of the occlusion, and prompt medical intervention is crucial to restore blood flow and minimize permanent vision loss.
Healthcare Professionals: Disease Ontology ID - DOID:13098
Pathophysiology: Central retinal artery occlusion (CRAO) is a condition characterized by the sudden loss of blood supply to the central retinal artery, leading to ischemia and potential irreversible damage to the retina.

Pathophysiology:
1. **Arterial Blockage:** CRAO commonly results from an embolus (e.g., a thrombus or a cholesterol embolus) blocking the central retinal artery. Less commonly, it can be caused by vasospasm, orbital trauma, or systemic inflammatory diseases like giant cell arteritis.

2. **Ischemia:** The blockage restricts blood flow, resulting in ischemia (lack of oxygen) to the inner layers of the retina, especially the inner retinal layers, which are most metabolically active and highly dependent on arterial blood supply.

3. **Retinal Damage:** Within minutes to hours of the occlusion, the lack of oxygen leads to retinal cell injury and death, starting with the ganglion cells and progressing to the entire inner retina. This damage is often irreversible if blood flow is not quickly restored.

4. **Vision Loss:** The immediate consequence is a sudden, painless loss of vision in the affected eye, which can range from partial to complete blindness depending on the extent and duration of the occlusion.

5. **Secondary Complications:** If the occlusion persists, secondary complications such as retinal neovascularization or glaucoma may occur due to prolonged ischemia and subsequent retinal hypoxia.

Understanding the rapid and irreversible nature of CRAO underlines the importance of urgent medical evaluation and intervention to restore arterial blood flow and potentially preserve vision.
Carrier Status: Central retinal artery occlusion (CRAO) is not a hereditary condition, so there is no carrier status associated with it. CRAO is typically caused by an embolism or thrombosis that results in a blockage of the central retinal artery, leading to sudden, painless vision loss in the affected eye.
Mechanism: The ophthalmic artery branches off into the central retinal artery which travels with the optic nerve until it enters the eye. This central retinal artery provides nutrients to the retina of the eye, more specifically the inner retina and the surface of the optic nerve. Variations, such as branch retinal artery occlusion, can also occur. Central retinal artery occlusion is most often due to emboli blocking the artery and therefore prevents the artery from delivering nutrients to most of the retina. These emboli originate from the carotid arteries most of the time but in 25% of cases, this is due to plaque build-up in the ophthalmic artery. The most frequent site of blockage is at the most narrow part of the artery which is where the artery pierces the dura covering the optic nerve. Some people have cilioretinal arterial branches, which may or may not be included in the blocked portion.
Treatment: While no treatment has been clearly demonstrated to be benefit for CRAO in large systematic reviews of randomized clinical trials, many of the following are frequently used:
Lowering intraocular pressure;
Dilating the CRA;
Increasing oxygenation;
Isovolemic hemodilution;
Anticoagulation;
Dislodging or fragmenting thrombus or embolus;
Thrombolysis; and
Hyperbaric oxygen.To achieve the best outcome for a person with CRAO, it is important to identify the condition in a timely manner and to refer to the appropriate specialist.
Compassionate Use Treatment: Central retinal artery occlusion (CRAO) is a serious condition that often leads to acute vision loss. While standard treatments are limited, several off-label and experimental treatments have been explored under compassionate use:

1. **Hyperbaric Oxygen Therapy (HBOT):** This treatment increases the amount of dissolved oxygen in the blood, which can help to restore retinal function. It is sometimes used off-label for CRAO.

2. **Intravitreal Injection of Fibrinolytic Agents:** Drugs like tissue plasminogen activator (tPA) are used to dissolve blood clots and may be administered directly into the eye.

3. **Carbogen Inhalation Therapy:** This involves breathing a gas mixture containing carbon dioxide and oxygen to dilate retinal arteries and improve blood flow.

4. **Anterior Chamber Paracentesis:** This minor surgical procedure involves the removal of a small amount of fluid from the front part of the eye to lower intraocular pressure and potentially improve blood flow.

5. **Laser Embolectomy:** Using laser technology to break up or remove the blockage within the retinal artery is another experimental approach.

6. **Intra-Arterial Thrombolysis:** Administering thrombolytic agents directly into the ophthalmic artery can help dissolve the clot causing the occlusion. This is a more invasive procedure.

These treatments are considered experimental or off-label and should be discussed with a healthcare provider to weigh potential risks and benefits.
Lifestyle Recommendations: For Central Retinal Artery Occlusion (CRAO), lifestyle recommendations focus primarily on managing and reducing the risk factors that can contribute to the condition. Key recommendations include:

1. **Manage Blood Pressure**: Maintain healthy blood pressure levels through diet, exercise, and medications as prescribed by a healthcare provider.

2. **Control Diabetes**: If diabetic, keep blood sugar levels well-managed with proper diet, physical activity, and medication.

3. **Cholesterol Management**: Reduce cholesterol levels through a healthy diet rich in fruits, vegetables, and whole grains, and consider medications if prescribed by your doctor.

4. **Quit Smoking**: Smoking cessation is crucial as it significantly increases the risk of vascular problems.

5. **Healthy Diet**: Adhere to a heart-healthy diet that includes reducing saturated fats, trans fats, cholesterol, and sodium.

6. **Regular Exercise**: Engage in regular physical activity, such as walking, cycling, or swimming, to improve cardiovascular health.

7. **Regular Medical Check-ups**: Regular visits to your healthcare provider can help monitor and manage risk factors like hypertension, hyperlipidemia, and diabetes.

8. **Weight Management**: Maintain a healthy weight to reduce strain on the cardiovascular system.

By following these lifestyle recommendations, individuals can potentially lower their risk of CRAO and other cardiovascular events.
Medication: There are no specific medications proven to be effective for central retinal artery occlusion (CRAO) in terms of restoring vision. Treatment is time-sensitive and focuses on measures to improve blood flow to the retina. Some methods include ocular massage, anterior chamber paracentesis, and hyperbaric oxygen therapy. In acute settings, certain techniques like lowering intraocular pressure with medications (e.g., acetazolamide) or managing underlying risk factors may be attempted. Immediate referral to a specialist is critical.
Repurposable Drugs: Central retinal artery occlusion (CRAO) is a serious condition characterized by sudden, painless vision loss due to the blockage of the central retinal artery. Several repurposable drugs have been researched for their potential benefits in CRAO, though none are definitively approved specifically for this condition. These include:

1. **Acetazolamide**: Traditionally used for glaucoma, it can help reduce intraocular pressure.
2. **Nitroglycerin**: Applied topically to induce vasodilation.
3. **Hyperbaric oxygen therapy**: Not a drug, but an intervention that can enhance oxygen delivery to the retina.
4. **Tissue plasminogen activator (tPA)**: A thrombolytic agent commonly used in stroke management; however, its use in CRAO is still under investigation and not universally endorsed due to mixed outcomes and potential risks.

It is important to consult with a healthcare provider for the most appropriate treatment tailored to individual cases.
Metabolites: Central retinal artery occlusion (CRAO) primarily affects the retinal tissues by significantly reducing blood and oxygen supply. However, specific metabolites directly associated with CRAO are not well-documented. The condition is more about the ischemic damage it causes than changes in particular metabolites. The primary focus in medical literature concerns the ischemia and potential resulting tissue damage rather than specific metabolic biomarkers.
Nutraceuticals: For central retinal artery occlusion (CRAO), there is no well-established evidence supporting the efficacy of nutraceuticals for treatment or prevention. CRAO is a medical emergency that typically requires immediate medical intervention to attempt to restore blood flow to the retina and minimize vision loss. Potential treatments may include ocular massage, hyperbaric oxygen therapy, or intra-arterial thrombolysis, among others. Nutraceuticals are not a substitute for these medical treatments.
Peptides: Central retinal artery occlusion (CRAO) is a serious condition characterized by the sudden loss of vision due to the blockage of the central retinal artery. The use of peptides for treatment or management of CRAO is currently not a standard practice and is still under research.

Nanotechnology offers promising avenues for developing new treatments for CRAO. Nanoparticles can potentially be used to deliver thrombolytic agents directly to the site of the occlusion, improve retinal protection, or even facilitate tissue regeneration. However, clinical applications of these technologies are still largely experimental and require further investigation.