ICD-10 Code H46.12 – Retrobulbar neuritis, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H46.12 – Retrobulbar neuritis, left eye
What it is
H46.12 identifies inflammation or demyelinating optic neuritis affecting the left eye behind the globe. Use it when documentation specifically states retrobulbar neuritis or optic neuritis in the left eye.
Clinical signs
Common findings include reduced visual acuity, pain with eye movement, and diminished color vision. Clinical features vary; refer to documentation, especially if the note identifies unilateral left-sided optic nerve involvement.
When to use this code
Use H46.12 when the provider documents retrobulbar neuritis, optic neuritis, or demyelinating optic nerve inflammation limited to the left eye. It is also appropriate when the record clearly links the diagnosis to the left optic nerve without naming another cause.
If the chart only says “optic neuritis” without laterality, check documentation before assigning this code. Confirm whether the condition is acute, unspecified, or due to another documented disorder.
Do not use for
Do not use this code for visual loss, eye pain, or optic atrophy without a documented diagnosis of retrobulbar neuritis. Check documentation if the condition is secondary to infection, ischemia, or another specific cause.
Coding tip
Always verify laterality in the assessment or impression before coding H46.12.