Injury of oculomotor nerve, left side, initial encounter

This diagnosis code signifies damage to the third cranial nerve (oculomotor nerve) affecting the left eye. Such an injury can lead to impaired eye movement, ptosis (drooping eyelid), and pupillary abnormalities on the left side. It specifically indicates the initial phase of treatment for this nerve injury.

Apply this code for a patient presenting with a newly diagnosed or acutely treated injury to the left oculomotor nerve. Documentation should clearly state the left-sided involvement and indicate that this is the first time the patient is receiving active treatment for this specific injury. Examples include trauma-induced nerve damage or iatrogenic injury during a surgical procedure.

• Ensure laterality is explicitly documented as "left" for the oculomotor nerve injury.
• Verify that the encounter is truly the "initial encounter" for active treatment; subsequent encounters for follow-up care would use a different seventh character.
• Consider co-reporting with an external cause code (V00-Y99) to describe the circumstances of the injury, if applicable.