ICD-10 Code H18.23 – Secondary corneal edema (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.23 – Secondary corneal edema
What it is
Secondary corneal edema means swelling of the cornea caused by another eye condition, surgery, trauma, or inflammation. It reflects impaired corneal fluid control rather than a primary corneal disorder.
Clinical signs
Common findings include corneal clouding, blurred vision, and visible stromal or epithelial edema. Clinical features vary; refer to documentation for the underlying cause and laterality if recorded.
When to use this code
Use H18.23 when the provider documents corneal edema as secondary to another condition, such as postoperative change or another ocular disease. Code it when the record clearly identifies the edema as secondary and not a primary corneal edema diagnosis. Check documentation if the cause is not stated.
Do not use for
Do not use this code for unspecified corneal edema without documentation of a secondary cause. Avoid it when the chart describes a different corneal disorder or when the edema is not confirmed by the provider.
Coding tip
Link H18.23 to the documented underlying eye condition whenever the record supports that relationship.