ICD-10 Code H18.233 – Secondary corneal edema, bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.233 – Secondary corneal edema, bilateral
What it is
H18.233 identifies corneal swelling in both eyes that occurs secondary to another eye condition or prior ocular event. Use it when the edema is documented as bilateral and not primary corneal edema.
Clinical signs
Typical findings include corneal clouding, reduced transparency, and blurred vision in both eyes. Clinical features vary; refer to documentation for the underlying cause and whether the edema is acute or chronic.
When to use this code
Use this code when the record states secondary corneal edema affecting both corneas, such as after surgery, inflammation, trauma, or another documented corneal disorder. Code the underlying condition separately when it is also documented and reportable.
Apply the bilateral code only if both eyes are involved. If the note says unilateral, unspecified, or does not clearly identify secondary edema, check documentation before assigning H18.233.
Do not use for
Do not use this code for primary corneal edema or for edema limited to one eye. Check documentation if the swelling is due to a different corneal diagnosis that should be coded instead.
Coding tip
Confirm both laterality and the documented cause before coding, and sequence the underlying disorder when appropriate.