ICD-10 Code H18.542 – Lattice Corneal Dystrophy, Left Eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.542 – Lattice corneal dystrophy, left eye
What it is
This code identifies lattice corneal dystrophy in the left eye, a hereditary corneal disorder marked by abnormal protein deposits in the cornea. It can cause progressive corneal clouding and visual disturbance.
Clinical signs
Typical findings include branching, lattice-like lines in the corneal stroma, often with recurrent erosions or reduced vision. Clinical features vary; refer to documentation.
When to use this code
Use H18.542 when the provider documents lattice corneal dystrophy specifically affecting the left eye. You should code it from ophthalmology notes, exam findings, or a confirmed diagnosis statement.
Do not assume laterality from a general corneal dystrophy diagnosis. If the record only says corneal dystrophy without side, check documentation.
Do not use for
Do not use this code for corneal dystrophy in the right eye, bilateral disease, or unspecified laterality. Do not use it for corneal scarring or other non-lattice corneal disorders.
Coding tip
Verify laterality in the assessment or impression section before assigning H18.542.