ICD-10 Code H51.22 – Internuclear ophthalmoplegia, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H51.22 – Internuclear ophthalmoplegia, left eye
What it is
H51.22 identifies internuclear ophthalmoplegia affecting the left eye. It describes a disorder of eye movement coordination, not a disease cause by itself, and usually reflects a problem in the brainstem pathways that control horizontal gaze.
Clinical signs
Typical findings include impaired adduction of the left eye during horizontal gaze and abnormal coordination between the eyes. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents internuclear ophthalmoplegia specifically involving the left eye. It may appear in neurologic or ophthalmic assessments, imaging follow-up, or problem lists when the laterality is clearly stated. Check documentation if the note only says internuclear ophthalmoplegia without laterality.
Do not use for
Do not use this code for unspecified internuclear ophthalmoplegia or for eye movement disorders without documented left-sided involvement. If the record describes a different neurologic cause or another ocular motility disorder, code that condition instead.
Coding tip
Always confirm laterality in the provider note before assigning H51.22.