Navigate Up

Pediatric Center - A-Z Index

#
Q
Z

Print This Page

Keratoconus

Keratoconus is an eye disease that affects the structure of the cornea. The cornea is the clear tissue that covers the front of the eye.

With this condition, the shape of the cornea slowly changes shape from round to a cone shape. The eye bulges out. This causes vision problems.

Causes

The cause is unknown. It is likely that the tendency to develop keratoconus is present from birth. The condition may be due to a defect in collagen. This is the tissue that provides the shape and strength to the cornea.

Allergy and eye rubbing may speed up the damage.

There is a link between keratoconus and Down syndrome .

Symptoms

The earliest symptom is a slight blurring of vision that cannot be corrected with glasses. (Vision can most often be corrected to 20/20 with rigid, gas-permeable contact lenses.) Over time, you may have eye halos, glare, or other night vision problems.

Most people who develop keratoconus have a history of being nearsighted . The nearsightedness tends to become worse over time. As the problem gets worse, astigmatism develops.

Keratoconus is often discovered during the teenage years. It may also develop in older people.

Exams and Tests

The most accurate test for this problem is called corneal topography, which creates a map of the curve of the cornea.

A slit-lamp exam of the cornea can diagnose the disease in the later stages.

A test called pachymetry can be used to measure the thickness of the cornea.

Treatment

Contact lenses are the main treatment for most patients with keratoconus. For people with the condition, wearing sunglasses outdoors after being diagnosed may help slow or prevent the progress of the disease. For many years, the only surgical treatment has been corneal transplantation .

The following newer technologies may delay or prevent the need for corneal transplantation:

  • High-frequency radio energy (conductive keratoplasty) changes the shape of the cornea so contact lenses work better.
  • Corneal implants (intracorneal ring segments) change the shape of the cornea so contact lenses work better
  • Corneal cross-linking is an experimental treatment that causes the cornea to become hard. This stops the condition from getting worse. The cornea can then be reshaped with laser vision correction.

Outlook (Prognosis)

In most cases vision can be corrected with rigid gas-permeable contact lenses.

If corneal transplantation is needed, results are very often good. However, the recovery period can be long. Many people still need contact lenses after the surgery.

Possible Complications

There is a risk of rejection after a cornea transplant, but the risk is much lower than with other organ transplants.

You should not have laser vision correction (such as LASIK) if you have any degree of keratoconus. Corneal topography is done beforehand to rule out people with this condition.

In rare cases, other laser vision correction procedures such as PRK may be safe for people with mild keratoconus.

When to Contact a Medical Professional

Young people whose vision cannot be corrected to 20/20 with glasses should be checked by an eye doctor familiar with keratoconus. Parents with keratoconus should consider having their children screened for the disease starting at age 10.

Prevention

There is no way to prevent this condition. Some doctors believe that people should take steps to control allergies and avoid rubbing their eyes.

References

Dahl BJ, Spotts E, Truong JQ. Corneal collagen cross-linking: an introduction and literature review. Optometry. 2012 Jan;83(1):33-42.

Jain A, Paulus YM, Cockerham GC, Kenyon KR. Keratoconus and other noninflammatory corneal thinning disorders. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 4, chap 16C.

Sugar J, Batta P. Keratoconus and other ectasias. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. St. Louis, MO: Elsevier Mosby; 2013:chap 4.18.

Updated: 9/2/2014

Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.


©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com