What causes keratoconus?

The exact cause of keratoconus is unknown. Both genetic and environmental factors may play a role in the development of keratoconus.

The genetic factors involve abnormalities in the structure of collagen, which result in a weak and flexible cornea. Keratoconus is more common in people with Down syndrome, Marfan syndrome, and Leber congenital amaurosis, and certain genetic conditions. In these cases, the cause depends on the specific condition.

Environmental factors may include living in sunny, hot areas of the world, while eye-rubbing is a major behavioral factor in the disease. Malfunctioning enzymes that normally help maintain the health of the cornea may play a role. All of these factors contribute to the main problem in keratoconus, which is the defective collagen structure that results in thinning and irregularity of the cornea. Keratoconus occurs more frequently in patients with atopy (asthma and eczema) or severe ocular allergies. It may also be linked to hormonal factors because it is more frequent during puberty and also may progress during pregnancy.

Last updated on 05-01-20

How is keratoconus treated?

Treatment depends on the severity of the keratoconus symptoms and may include: :

  • Eyeglasses and contact lens: During early stages, vision can be corrected with eyeglasses. As the condition progresses, rigid contacts may need to be worn so that light entering the eye is refracted evenly and vision is not distorted. You should also refrain from rubbing your eyes, as this can aggravate the thin corneal tissue and make symptoms worse.
  • Laser: Laser can improve corneal abrasions and contact lens tolerance.
  • Implants: Keratoconus can also be treated with Intacs, which are small curved implantable corneal devices that can reshape the cornea. Intacs are FDA approved and can help flatten the steep cornea found in keratoconus.
  • Collagen: Collagen cross-linking is a new treatment that uses a special laser and eyedrops to promote “cross-linking” or strengthening of the collagen fibers that make up the cornea. This treatment may flatten or stiffen the cornea, preventing further protrusion.
  • Corneal transplant: When good vision is no longer possible with other treatments, a corneal transplant may be recommended. This surgery is only necessary in about 10 percent to 20 percent of patients with keratoconus. In a corneal transplant, the diseased cornea is removed and replaced with a healthy donor cornea. A transplanted cornea heals slowly. It can take up to a year or more to recover good vision after corneal transplantation. Usually contact lenses are needed afterwards.
  • Deep Anterior Lamellar Keratoplasty: With this procedure, only the front and middle layers of the cornea are transplanted. The benefits of this transplant over the “full” cornea transplant is a much faster healing period and less risk of rejection.

Last updated on 05-01-20

Name: The Global Keratoconus Foundation Email:,com_contact/Itemid,3/ Url:
Name: Keratoconus Group Url:
Name: Keratomania: Keratoconus Support and Awareness Url:

Note, these links are external searches against the National Laboratory of Medicine's drug database. You may need to adjust the search if there are no results found.

Drug Name Generic Name
Photrexa Viscous riboflavin ophthalmic solution & ultraviolet A

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