ICD-10 Code H21.521 – Goniosynechiae, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.521 – Goniosynechiae, right eye
What it is
Goniosynechiae means adhesions in the anterior chamber angle of the eye. This code specifies the right eye, so you should use it when documentation identifies angle closure or synechial adhesions on that side.
Clinical signs
Findings may include narrowed or closed angle structures on gonioscopy and evidence of peripheral iris adhesion. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents goniosynechiae in the right eye, including chronic angle changes confirmed on exam or imaging. It is also appropriate when the record clearly states peripheral anterior synechiae affecting the right eye. Check documentation if laterality is unclear.
Do not use for
Do not use this code for left eye or bilateral disease, or when the chart only notes glaucoma without documented synechial adhesions. Do not assign it if the finding is suspected but not confirmed.
Coding tip
Verify laterality and the specific term “goniosynechiae” before coding.