ICD-10 Code H40.10 – Unspecified open-angle glaucoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H40.10 – Unspecified open-angle glaucoma
What it is
H40.10 identifies open-angle glaucoma when the type is known but the record does not specify laterality or further detail. It indicates a chronic optic neuropathy associated with glaucomatous damage.
Clinical signs
Findings may include increased optic nerve cupping, visual field loss, and elevated intraocular pressure, though pressure can be normal. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents open-angle glaucoma without specifying whether it is primary, secondary, or another subtype. It also fits when laterality or other detail is missing from the note. If the record names a more specific glaucoma diagnosis, code that instead.
Do not use for
Do not use H40.10 for angle-closure glaucoma, glaucoma suspect, or secondary glaucoma when those are documented. If the chart gives a more specific open-angle type, check documentation and code that diagnosis.
Coding tip
Review the ophthalmology note for subtype and laterality before selecting this unspecified code.