central retinal artery occlusion

Central Retinal Artery Occlusion (CRAO) Description

Central retinal artery occlusion, also known as CRAO, is a serious medical condition that affects the eye. It occurs when the central artery in the retina becomes blocked, usually due to an embolus or thromboembolism.

• Sudden Vision Loss: CRAO is characterized by sudden and severe vision loss in one eye, often without any warning signs or symptoms.
• Painless Condition: The condition is typically painless, which can make it difficult for patients to recognize the severity of their situation.
• Retinal Whitening and Cherry Red Spot: In central retinal artery occlusion, the retina becomes edematous and opacified, leading to a whitish appearance. The fovea, being devoid of nerve fiber layer, remains cherry red, creating a distinctive "cherry red spot" on fundoscopic examination.
• Risk Factors: Individuals with high blood pressure, diabetes, or thicker-than-normal blood are at higher risk for developing CRAO.

Key Statistics

• 80% of affected individuals have a final visual acuity of counting fingers or worse [2].
• About 25% of people who develop CRAO have an extra artery called a cilioretinal artery in their eyes, which can greatly lessen the chances of damage to the retina [15].

Importance of Prompt Medical Attention

CRAO is considered an ophthalmic emergency and requires immediate medical attention. Delaying treatment can lead to permanent vision loss or even blindness.

References:

[1] - Central retinal artery occlusion (CRAO) is an ophthalmic emergency that can lead to sudden and severe vision loss.[1]

[2] - Patients typically present with profound, acute, painless monocular visual loss—with 80% of affected indi­viduals having a final visual acuity of counting fingers or worse.

[15] - A blockage in the main artery in the retina is called central retinal artery occlusion (CRAO), which often results in severe loss of vision. However, about 25% of people who develop CRAO have an extra artery called a cilioretinal artery in their eyes.

Central retinal artery occlusion (CRAO) can be diagnosed through several tests, which are crucial in confirming the condition and ruling out other potential causes of vision loss.

• Fundoscopy: This is a critical test that allows ophthalmologists to examine the retina and identify characteristic findings associated with CRAO. A dilated eye examination may reveal a "cherry red spot," where the center of the macula appears red, while the surrounding retina appears pale [2]. Fundoscopy can be performed using a slit lamp biomicroscope.
• Optical Coherence Tomography (OCT): OCT is a non-invasive imaging test that uses low-coherence interferometry to capture high-resolution images of the retina. It can reveal changes in retinal thickness and structure, which may indicate CRAO [7].
• Carotid Doppler Ultrasonography: This test evaluates blood flow through the carotid arteries, which can help identify potential embolic sources contributing to CRAO [9].
• Magnetic Resonance Angiography (MRA) or Computed Tomography Angiography (CTA): These imaging tests can also be used to evaluate blood flow and identify any blockages in the carotid arteries, which may be causing CRAO [9].

These diagnostic tests are essential in confirming a diagnosis of central retinal artery occlusion and identifying potential treatable risk factors. Early detection and treatment can significantly impact patient outcomes.

References: [1] Central retinal artery occlusion (CRAO) is an ophthalmic emergency that can lead to sudden and severe vision loss.[1] [2] A blockage in the main artery in the retina is called central retinal artery occlusion (CRAO), which often results in severe loss of vision. ... Diagnostic testing. CRAO is usually diagnosed by a dilated eye examination that shows a “cherry red spot,” where the center of the macula appears red, with the surrounding retina pale due to the ... [7] by JI Lim · Cited by 1 — Diagnostic procedures. Optical coherence tomography reveals ... Treatment Options for Central Retinal Artery Occlusion. Curr Treat Options ... [9] Feb 16, 2023 — Evaluation of the carotids with carotid Doppler ultrasonography, magnetic resonance angiography (MRA), or computed tomography angiography can be ...

Treatment Options for Central Retinal Artery Occlusion (CRAO)

Central retinal artery occlusion (CRAO) is a medical emergency that requires prompt attention. While there are no evidence-based treatments, various pharmacological interventions have been explored to improve outcomes.

• Acetazolamide: Administering acetazolamide 500 mg IV or PO can help lower intraocular pressure and increase retinal perfusion [3][4]. This medication is also used in the treatment of glaucoma.
• Vasodilatory drugs: Vasodilators, such as those used to treat glaucoma, may be administered to increase retinal perfusion [5].
• Hyperventilation and carbogen inhalation: Hyperventilation with a mixture of 95% oxygen and 5% carbon dioxide (carbogen) can help dilate the retinal vessels and improve perfusion [5].

Other Therapies

In addition to pharmacological interventions, other therapies have been studied for their potential benefits in treating CRAO. These include:

• Anterior chamber paracentesis: This procedure involves removing fluid from the anterior chamber of the eye to reduce intraocular pressure.
• **Hyperbaric oxygen

Central retinal artery occlusion (CRAO) has several differential diagnoses, which are conditions that can present with similar symptoms and must be ruled out to confirm the diagnosis of CRAO.

• Branch Retinal Artery Occlusion (BRAO): This is a condition where there is an occlusion of one or more branches of the retinal artery. It typically presents with sectoral whitening in the path of the affected branch, whereas CRAO has retinal artery boxcarring and whitening in all four quadrants [2].
• Giant Cell Arteritis (GCA): This is a form of vasculitis that can cause occlusion of the central retinal artery. It is more common in individuals over 50 years old and requires prompt diagnosis and treatment with systemic corticosteroids [3].
• Carotid Disease: CRAO may be caused by emboli dislodged from an unstable atherosclerotic plaque or a cardiac source, making carotid disease a differential diagnosis [8][9].
• Retinal Vein Occlusion (RVO): While not directly related to CRAO, RVO can present with similar symptoms and must be ruled out in the differential diagnosis.
• Purtscher Retinopathy and Purtscher-like Retinopathy: These are conditions that can cause retinal ischemia and must be considered in the differential diagnosis of CRAO [11].
• Lysosomal Storage Disorders: Certain lysosomal storage disorders, such as Fabry disease, can present with a cherry red spot at the macula, which is similar to the presentation of CRAO [10].

It's essential to consider these differential diagnoses when evaluating patients with symptoms suggestive of central retinal artery occlusion. A thorough medical history, physical examination, and diagnostic tests (such as ophthalmoscopy, fluorescein angiography, and carotid ultrasound) can help differentiate between these conditions and confirm the diagnosis of CRAO.