Pannus (corneal), left eye

This code describes the presence of pannus in the left eye. Corneal pannus is a condition characterized by the growth of a vascularized connective tissue layer over the cornea, often associated with chronic inflammation or irritation. This vascularization can impair vision by obstructing the light path and causing corneal opacification.

Use this code when documentation specifies corneal pannus affecting the left eye. This typically occurs in patients with chronic ocular surface diseases such as trachoma, severe dry eye, or contact lens-induced keratitis. Documentation should clearly indicate the presence and laterality of the pannus.

• Ensure the documentation specifies "pannus" and not another corneal opacity or lesion.
• Verify laterality; this code is specific to the left eye. Use H16.421 for the right eye and H16.423 for bilateral involvement.
• Consider coding any underlying cause of the pannus, such as chronic conjunctivitis or keratitis, as a secondary diagnosis.