2026 ICD-10-CM Diagnosis Code H16

Clinical Information

• Acanthamoeba Keratitis

  infection of the cornea by an ameboid protozoan which may cause corneal ulceration leading to blindness.

• Corneal Ulcer

  loss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue; usually caused by bacterial, fungal, or viral infection.

• Keratitis

  inflammation of the cornea.

• Keratitis, Dendritic

  a form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (dictionary of visual science, 3d ed)

• Keratitis, Herpetic

  a superficial, epithelial herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (keratitis, dendritic). (dictionary of visual science, 3d ed)

• Grade 3 Keratitis, CTCAE|CTCAE Grade 3 Keratitis (corneal inflammation/corneal ulceration)|Grade 3 Keratitis|Grade 3 Keratitis (corneal inflammation/corneal ulceration)

  symptomatic with marked decrease in visual acuity (best corrected visual acuity worse than 20/40 or more than 3 lines of decreased vision from known baseline, up to 20/200); corneal ulcer; limiting self-care adl or severe impact on age-appropriate normal daily activity (pediatric)

• Photokeratitis|Arc Welder's Eye|Arc eye|Ultraviolet Keratitis|Ultraviolet Keratitis|Welder's Flash

  injury to the cornea secondary to ultraviolet light.

• Stromal Keratitis|Stromal keratitis

  a corneal inflammation affecting the stromal layer.

• Acanthamoeba Keratitis

  keratitis due to infection by acanthamoeba; it is usually associated with soft contact lens wear, particularly overnight wear.

• Dendritic Keratitis

  infection of the cornea with herpes simplex virus, resulting in branching ulcers of the corneal tissue.

• Fungal Keratitis

  keratitis caused by fungi.

• Grade 1 Keratitis, CTCAE|CTCAE Grade 1 Keratitis (corneal inflammation/corneal ulceration)|Grade 1 Keratitis|Grade 1 Keratitis (corneal inflammation/corneal ulceration)

  asymptomatic; clinical or diagnostic observations only; intervention not indicated

• Grade 2 Keratitis, CTCAE|CTCAE Grade 2 Keratitis (corneal inflammation/corneal ulceration)|Grade 2 Keratitis|Grade 2 Keratitis (corneal inflammation/corneal ulceration)

  symptomatic; moderate decrease in visual acuity (best corrected visual acuity 20/40 and better or 3 lines or less decreased vision from known baseline)

• Grade 3 Keratitis, CTCAE|CTCAE Grade 3 Keratitis (corneal inflammation/corneal ulceration)|Grade 3 Keratitis|Grade 3 Keratitis (corneal inflammation/corneal ulceration)

  symptomatic with marked decrease in visual acuity (best corrected visual acuity worse than 20/40 or more than 3 lines of decreased vision from known baseline, up to 20/200); corneal ulcer; limiting self care adl

• Grade 4 Keratitis, CTCAE|CTCAE Grade 4 Keratitis (corneal inflammation/corneal ulceration)|Grade 4 Keratitis|Grade 4 Keratitis (corneal inflammation/corneal ulceration)

  perforation; best corrected visual acuity of 20/200 or worse in the affected eye

• Infectious Keratitis|Infective Keratitis

  inflammation of the cornea secondary to an infectious process.

• Keratitis, CTCAE|Keratitis|Keratitis|Keratitis (corneal inflammation/corneal ulceration)

  a disorder characterized by inflammation to the cornea of the eye.

• PAX6 wt Allele|AN|AN2|Aniridia, Keratitis Gene|D11S812E|MGC17209|MGDA|Paired Box 6 wt Allele|Paired Box Gene 6 (Aniridia, Keratitis) Gene|WAGR

  human pax6 wild-type allele is located in the vicinity of 11p13 and is approximately 29 kb in length. this allele, which encodes paired box protein pax-6, plays a role in the mediation of transcription. mutations in the gene are associated with a number of congenital disorders of the eye.

• Photokeratitis|Ultraviolet Keratitis|Ultraviolet Keratitis

  injury to the cornea secondary to ultraviolet light.

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:

• Refractive errors
• Allergies
• Infections
• Injuries
• Dystrophies - conditions in which parts of the cornea lose clarity due to a buildup of cloudy material

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

NIH: National Eye Institute

Code History

• FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
• FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
• FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
• FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
• FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
• FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
• FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
• FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
• FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
• FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
• FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.