Symptoms and causes

Symptoms

Signs and symptoms of keratoconus may change as the disease progresses. They include:

  • Blurred or distorted vision
  • Increased sensitivity to bright light and glare, which can cause problems with night driving
  • A need for frequent changes in eyeglass prescriptions
  • Sudden worsening or clouding of vision

When to see a doctor

See your eye doctor (ophthalmologist or optometrist) if your eyesight is worsening rapidly, which might be caused by an irregular curvature of the eye (astigmatism). He or she may also look for signs of keratoconus during routine eye exams.

If you're considering laser-assisted in-situ keratomileusis (LASIK) eye surgery, your doctor will check for signs of keratoconus before you proceed.

Causes

No one knows what causes keratoconus.

Risk factors

These factors can increase your chances of developing keratoconus:

  • Having a family history of keratoconus
  • Rubbing your eyes vigorously
  • Having certain conditions, such as retinitis pigmentosa, Down syndrome, Ehlers-Danlos syndrome, hay fever and asthma

Complications

In some situations, your cornea may swell quickly and cause sudden reduced vision and scarring of the cornea. This is caused by a condition in which the inside lining of your cornea breaks down, allowing fluid to enter the cornea (hydrops).

In advanced keratoconus, your cornea may become scarred, particularly where the cone forms. A scarred cornea causes worsening vision problems and may require corneal transplant surgery.

Jan. 30, 2016
References
  1. Wayman LL. Keratoconus. http://www.uptodate.com/home. Accessed Nov. 24, 2015.
  2. What is keratoconus? American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus.cfm. Accessed Nov. 24, 2015.
  3. Keratoconus treatment. American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus-treatment.cfm. Accessed Nov. 24, 2015.
  4. van der Worp E, et al. Modern scleral contact lenses: A review. Contact Lens & Anterior Eye. 2014;37:240.
  5. Raiskup F, et al. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: Ten-year results. Journal of Cataract and Refractive Surgery. 2015;41:41.
  6. Jinabhai A, et al. Optical quality and visual performance with customised soft contact lenses for keratoconus. Opthalmic and Physiological Optics. 2014;34:528.
  7. Amayem AF, et al. Refractive and visual outcomes of penetrating keratoplasty versus deep anterior lamellar keratoplasty with hydrodissection for treatment of keratoconus. Cornea. 2013;32:e2.
  8. Keratoconus diagnosis. American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus-diagnosis.cfm. Accessed Nov. 24, 2015.
  9. Riggin EA. Allscripts EPSi. Mayo Clinic, Rochester, Minn. July 27, 2015.
  10. Keratoconus. American Optometric Association. http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/keratoconus?sso=y. Accessed Dec. 23, 2015.
  11. Keratoconus. Merck Professional Version. http://www.merckmanuals.com/professional/eye-disorders/corneal-disorders/keratoconus. Accessed Dec. 23, 2015.
  12. Yanoff M, ed., et al. Testing of refraction. In: Ophthalmology. 4th ed. Edinburgh, U.K.: Mosby Elsevier; 2014. https://www.clinicalkey.com. Accessed Oct. 30, 2014.
  13. Yanoff M, ed., et al. Keratoconus and other ectasias. In: Ophthalmology. 4th ed. Edinburgh, U.K.: Mosby Elsevier; 2014. https://www.clinicalkey.com. Accessed Oct. 30, 2014.
  14. Patel SV (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 5, 2016.