H34.12 Central retinal artery occlusion, left eye

Name of the Condition

• Central Retinal Artery Occlusion, Left Eye

Summary

Central retinal artery occlusion (CRAO) is a blockage of the central retinal artery, which supplies blood to the retina. This blockage disrupts blood flow and can lead to sudden, painless vision loss in the affected eye. The condition is a medical emergency due to the risk of permanent retinal damage and vision impairment.

Causes

CRAO is typically caused by an embolus (e.g., from atherosclerotic plaque or cardiac sources) or thrombus blocking the central retinal artery. Other contributing factors may include vasospasm, inflammatory conditions, or trauma to the artery.

Risk Factors

• Advanced age
• Hypertension
• Atherosclerosis
• Cardiovascular disease
• Diabetes mellitus
• High cholesterol
• Smoking
• Hypercoagulable states
• Carotid artery disease

Symptoms

• Sudden, painless vision loss in the left eye
• Reduced visual acuity (e.g., "blacking out" or "fogging" of vision)
• Visual field defects (e.g., altitudinal or sectoral loss)
• Relative afferent pupillary defect (RAPD) in the left eye

Diagnosis

Diagnosis involves a comprehensive eye examination, including visual acuity testing, dilated funduscopy (to assess retinal whitening, cherry-red spot, or arterial narrowing), and imaging studies such as fluorescein angiography or optical coherence tomography (OCT) to evaluate retinal perfusion and structural changes.

Treatment Options

Treatment aims to restore blood flow and minimize retinal damage. Options may include ocular massage, anterior chamber paracentesis, or hyperbaric oxygen therapy. Systemic treatments (e.g., thrombolytics) are considered in select cases, though evidence is limited. Long-term management focuses on addressing underlying risk factors.

Prognosis and Follow-Up

Prognosis depends on the duration of occlusion and promptness of treatment. Vision may improve partially or remain severely impaired. Follow-up includes regular eye examinations to monitor for complications (e.g., neovascularization) and systemic risk factor management.

Complications

• Permanent vision loss
• Retinal ischemia
• Neovascularization of the iris or retina
• Secondary glaucoma

Lifestyle & Prevention

• Control hypertension, diabetes, and cholesterol
• Avoid smoking
• Maintain a heart-healthy diet and exercise routine
• Manage hypercoagulable states under medical guidance

When to Seek Professional Help

Seek immediate medical attention for sudden, painless vision loss in one eye, as delayed treatment increases the risk of permanent damage.

Tips for Medical Coders

Use H34.12 for confirmed central retinal artery occlusion of the left eye. Document laterality clearly and specify if the occlusion is acute or chronic. Include details on diagnostic findings (e.g., funduscopy results) to support code assignment.