ICD-10 Code H44.42 – Hypotony of eye due to ocular fistula (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H44.42 – Hypotony of eye due to ocular fistula
What it is
Use this code for abnormally low intraocular pressure caused by an ocular fistula, meaning an abnormal opening that allows fluid to escape from the eye. It identifies the cause of the hypotony rather than a general low-pressure state.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include a persistently soft eye, reduced intraocular pressure, and visual changes related to the pressure loss.
When to use this code
Use H44.42 when the provider documents hypotony of the eye and specifically links it to an ocular fistula. Apply it when the fistula is the stated cause, whether the condition is newly diagnosed or being followed. Check documentation if the record only says “hypotony” without a cause.
Do not use for
Do not use this code for hypotony from other causes, such as postoperative leakage or trauma, unless an ocular fistula is documented. Do not use it for unspecified low intraocular pressure.
Coding tip
Confirm the causal relationship in the note; the fistula must be documented as the reason for the hypotony.