ICD-10 Code H21.542 – Posterior synechiae (iris), left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.542 – Posterior synechiae (iris), left eye
What it is
H21.542 identifies adhesions between the posterior iris surface and the lens in the left eye. This code describes a structural eye finding, not a cause or underlying disease.
Clinical signs
Findings may include an irregular or distorted pupil, limited pupil movement, or visible iris-lens adhesions on exam. Clinical features vary; refer to documentation.
When to use this code
Use H21.542 when the record clearly documents posterior synechiae involving the left eye. It may appear as a complication of prior inflammation or other ocular disease, but code only the documented finding. If the laterality is not stated, check documentation before coding.
Do not use for
Do not use this code for right eye or bilateral posterior synechiae. Do not assign it when the chart mentions only uveitis, iritis, or another condition without documented iris adhesions.
Coding tip
Confirm laterality and the exact eye finding in the ophthalmology note before assigning H21.542.