Superior rectus muscle entrapment, left eye

This code signifies a condition where the left superior rectus muscle, responsible for upward gaze, becomes physically trapped or restricted, often within an orbital fracture or other structural anomaly. This entrapment limits the muscle's movement, leading to impaired ocular motility and potentially diplopia. It is a specific type of restrictive strabismus affecting a single extraocular muscle.

Use this code when documentation clearly indicates mechanical restriction of the left superior rectus muscle, typically confirmed by imaging (e.g., CT scan showing muscle incarceration) or forced duction testing. This diagnosis is common following orbital trauma, particularly blow-out fractures involving the orbital roof or superior wall.

• Ensure laterality is explicitly documented as "left eye" to support this specific code.
• Distinguish from paresis or paralysis of the superior rectus, which would be coded differently (e.g., H49.xx).
• Always sequence this code with the underlying cause, such as an orbital fracture (S02.1xx), if applicable.