ICD-10 Code H40.121 – Low-tension glaucoma, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H40.121 – Low-tension glaucoma, right eye
What it is
This code identifies low-tension glaucoma affecting the right eye. It is a glaucoma diagnosis in which optic nerve damage occurs despite intraocular pressure that is not elevated.
Clinical signs
Findings may include glaucomatous optic nerve cupping, corresponding visual field loss, and a normal or low measured intraocular pressure. Clinical features vary; refer to documentation.
When to use this code
Use H40.121 when the provider documents low-tension or normal-tension glaucoma in the right eye only. You may also use it when the record clearly links optic nerve damage and visual field changes to this diagnosis. If laterality is not documented, check documentation before coding.
Do not use for
Do not use this code for glaucoma of the left eye, both eyes, or unspecified laterality. Do not apply it when the note describes ocular hypertension without glaucoma.
Coding tip
Confirm laterality and the exact glaucoma type in the assessment before assigning H40.121.