ICD-10 Code H18.539 – Granular corneal dystrophy, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.539 – Granular corneal dystrophy, unspecified eye
What it is
Use this code for a corneal dystrophy with granular-appearing deposits when the affected eye is not specified in the record. It identifies a hereditary corneal opacity disorder, not an acute infection.
Clinical signs
Typical findings include discrete white or gray stromal opacities in the cornea, often described as breadcrumb-like or granular. Vision may be reduced, and clinical features vary; refer to documentation.
When to use this code
Assign H18.539 when the clinician documents granular corneal dystrophy but does not identify right, left, or bilateral eye involvement. Use it for problem lists, specialist notes, or encounter diagnoses when laterality is absent or unclear.
If the record names a specific eye, code that laterality instead. Check documentation when the note only says corneal dystrophy without confirming the granular subtype.
Do not use for
Do not use this code for infectious keratitis, corneal scars, or other corneal dystrophies. If the subtype or eye laterality is documented differently, choose the more specific code.
Coding tip
Review ophthalmology notes carefully for laterality and subtype before coding, because unspecified eye should be used only when the record truly lacks that detail.