Codes / ICD10CM / H49.02

H49.02 Third [oculomotor] nerve palsy, left eye

ICD10CM code

ICD10CM

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Name of the Condition

  • Third [oculomotor] nerve palsy, left eye

Summary

Third nerve palsy, left eye, involves weakness or paralysis of the oculomotor nerve, which controls most eye movements and pupil function. This can lead to double vision, drooping eyelid (ptosis), and pupil abnormalities. The condition affects the left eye specifically and may result from various underlying causes.

Causes

Causes can include trauma, aneurysms (especially of the posterior communicating artery), tumors, microvascular ischemia (often related to diabetes or hypertension), infections, or inflammation. In some cases, the cause remains unknown (idiopathic).

Risk Factors

  • Age (older adults)
  • History of diabetes or hypertension
  • Head trauma or injury
  • Prior aneurysms or vascular conditions
  • Inflammatory or infectious diseases affecting the nervous system

Symptoms

  • Double vision (diplopia), especially when looking in certain directions
  • Drooping eyelid (ptosis)
  • Dilated or unresponsive pupil
  • Difficulty moving the eye upward, downward, or inward
  • Head tilt to compensate for vision changes

Diagnosis

Diagnosis is made through a detailed eye exam, including tests of eye movement, pupil response, and alignment. Imaging studies like MRI or CT scans may be used to identify underlying causes such as aneurysms or tumors. Blood tests or other evaluations may be performed to assess for systemic conditions.

Treatment Options

Treatment depends on the underlying cause. Options may include observation, medications (e.g., for pain or inflammation), surgery (for aneurysms or tumors), or management of associated conditions like diabetes or hypertension. Eye patches or prisms may help with double vision.

Prognosis and Follow-Up

Prognosis varies based on the cause. Some cases resolve spontaneously, while others may require long-term management. Regular follow-up with an eye specialist is important to monitor symptoms and adjust treatment as needed.

Complications

Potential complications include persistent double vision, chronic ptosis, pupil abnormalities, or permanent vision loss if the underlying cause is not addressed promptly.

Lifestyle & Prevention

Managing risk factors like diabetes or hypertension may reduce the risk of microvascular ischemia. Avoiding head trauma and seeking prompt care for neurological symptoms can help prevent or minimize nerve damage.

When to Seek Professional Help

Seek immediate medical attention if you experience sudden double vision, drooping eyelid, or pupil changes, as these may indicate a serious underlying condition like an aneurysm or stroke.

Tips for Medical Coders

Document the affected eye (left) and any associated symptoms or underlying causes. Ensure clinical documentation supports the specific laterality and distinguishes this from bilateral or unspecified nerve palsy.

Medical Policies and Guidelines

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