H18.40 - Unspecified corneal degeneration

Version 2023
ICD-10:H18.40
Short Description:Unspecified corneal degeneration
Long Description:Unspecified corneal degeneration
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the eye and adnexa (H00–H59)
    • Disorders of sclera, cornea, iris and ciliary body (H15-H22)
      • Other disorders of cornea (H18)

H18.40 is a billable ICD-10 code used to specify a medical diagnosis of unspecified corneal degeneration. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Unspecified diagnosis codes like H18.40 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Index to Diseases and Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
H18.40371.40 - Corneal degeneration NOS

Patient Education


Corneal Disorders

Your cornea is the outermost layer of your eye. It is clear and shaped like a dome. The cornea helps to shield the rest of the eye from germs, dust, and other harmful matter. It also helps your eye to focus. If you wear contact lenses, they float on top of your corneas.

Problems with the cornea include:

Treatments of corneal disorders include medicines, corneal transplantation, and corneal laser surgery.

NIH: National Eye Institute


[Learn More in MedlinePlus]

Code History