ICD-10 Code H18.221 – Idiopathic corneal edema, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.221 – Idiopathic corneal edema, right eye
What it is
H18.221 identifies unexplained swelling of the cornea in the right eye. Use it when the chart documents corneal edema but does not name a specific cause.
Clinical signs
Typical findings include corneal clouding, thickening, and reduced clarity on exam. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents idiopathic corneal edema limited to the right eye. It also fits cases where the right cornea is edematous and no underlying disorder is recorded. If another cause is stated, code the documented condition instead.
Do not use for
Do not use it for corneal edema with a known cause, such as trauma, surgery, infection, or dystrophy. Check documentation if the laterality is not clearly right eye.
Coding tip
Confirm both laterality and “idiopathic” wording in the note before assigning H18.221.