ICD-10 Code H18.231 – Secondary corneal edema, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.231 – Secondary corneal edema, right eye
What it is
H18.231 identifies corneal swelling in the right eye that occurs secondary to another cause. It means the cornea has lost clarity because fluid has accumulated, and you should code the underlying condition when documented.
Clinical signs
Typical findings include corneal haze, reduced transparency, and blurred vision in the affected eye. Clinical features vary; refer to documentation for the cause, laterality, and whether edema is acute or chronic.
When to use this code
Use this code when the provider documents secondary corneal edema specifically in the right eye. It is appropriate when the edema is attributed to another eye disorder, surgery, trauma, or other documented cause.
Code the underlying condition separately when the record supports it. If the note only says corneal edema without laterality or cause, check documentation before assigning H18.231.
Do not use for
Do not use this code for corneal edema of the left eye, both eyes, or unspecified eye. Also avoid it when the record describes primary corneal edema or another corneal disorder without secondary edema.
Coding tip
Verify right-eye laterality and the documented cause before coding, and add the underlying diagnosis when it is clearly stated.