ICD-10 Code H18.602 – Keratoconus, unspecified, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.602 – Keratoconus, unspecified, left eye
What it is
This code identifies keratoconus affecting the left eye when the record does not specify a subtype. It describes a corneal thinning and bulging disorder that changes the eye’s shape and vision.
Clinical signs
Clinical features vary; refer to documentation. Common findings include progressive irregular astigmatism, blurred or distorted vision, and corneal thinning or cone-like protrusion on examination.
When to use this code
Use H18.602 when the clinician documents keratoconus in the left eye but does not name whether it is acute, stable, or another specified form. It is appropriate when the diagnosis is confirmed clinically or by corneal imaging and laterality is clearly left.
Do not use for
Do not use this code if the record identifies keratoconus in another eye or both eyes, or if a more specific keratoconus code is documented. Check documentation when the diagnosis is uncertain or only suspected.
Coding tip
Verify laterality and specificity in the ophthalmology note before assigning H18.602.