- Keratoconus Center
- Eye Diseases Pictures Slideshow
- Pink Eye Slideshow Pictures
- Eyes and Eye Conditions Quiz
- Patient Comments: Keratoconus - Cause
- Patient Comments: Keratoconus - Treatment
- Patient Comments: Keratoconus - Diagnosis
- Find a local Eye Doctor in your town
We see through the cornea, which is the clear, central part of the front surface of the eye. Normally, the cornea has a round shape, like a ball. Sometimes, however, the structure of the cornea is just not strong enough to hold this round shape. The normal pressure inside the eye makes the cornea bulge outward like a cone. This condition is called keratoconus.
What Causes Keratoconus?
Often the cause of keratoconus is unknown. Some studies have found that keratoconus runs in families, and that it happens more often in people with certain medical conditions. But most often, there is no eye injury or disease that could explain why the eye starts to change.
Keratoconus usually begins in the teenage years, but it can also start in childhood or up to about age 30. The changes in the shape of the cornea occur slowly, usually over several years.
Someone with keratoconus will notice that vision slowly becomes distorted. The change can stop at any time, or it can continue for several years. In most people who have keratoconus, both eyes are eventually affected.
Can Keratoconus Damage Vision?
Keratoconus can be dangerous if laser vision correction surgery -- LASIK or PRK is performed on the eye.
Anyone with even a small amount of keratoconus should not have laser vision correction surgery.
How Is Keratoconus Diagnosed?
The doctor may notice some things during the examination, or the patient may mention symptoms, that could be caused by keratoconus. These include:
- Sudden change of vision in just one eye.
- Double vision when looking with just one eye.
- Objects both near and far look distorted, but not blurred. In other words, small details of the objects are clear, but the shapes or colors look wrong. Later, distant objects do become blurred.
- Bright lights look like they have halos around them.
These things might be related to keratoconus, but your doctor must measure the curvature of the cornea to be certain. Several different instruments can be used to measure the curvature of the cornea.
One instrument, called a keratometer, shines a pattern of light onto the cornea. The shape of the reflection of the pattern tells the doctor how the eye is curved. There are also computerized instruments that make three-dimensional "maps" of the cornea, a process called corneal topography.
How Is Keratoconus Treated?
Only a doctor experienced in treating eye problems can recommend the right treatment for someone with keratoconus. Treatment usually starts with new eyeglasses, and then contact lenses are recommended. These will correct the vision problems caused by keratoconus.
Keratoconus changes vision in two ways:
- As the cornea changes from a ball shape to a cone shape, the smooth surface also becomes slightly wavy. This is called irregular astigmatism .
- As the front of the cornea expands, the eye becomes more nearsighted . That is, only nearby objects can be seen clearly. Anything too far away will look like a blur.
Will Surgery Correct Keratoconus?
For most people with keratoconus, the only treatment needed is the correct prescription for eyeglasses or contact lenses. A small number of cases of keratoconus keep getting worse, however, and, eventually, contact lenses cannot give clear vision. In other cases, the keratoconus or the use of contact lenses over the years will have side effects. These side effects can make the cornea cloudy. When these things happen, corneal transplantation might be recommended.
Reviewed by the doctors at The Cleveland Clinic Cole Eye Institute.
Edited by Charlotte E. Grayson, MD, WebMD, October 2004.
Daily Health News
Subscribe to MedicineNet's General Health Newsletter
Keratoconus - Cause
What do you think caused your keratoconus?Post View 2 Comments
Keratoconus - Treatment
How was your keratoconus treated?Post View 1 Comment
Keratoconus - Diagnosis
Please discuss the events and symptoms that led to a diagnosis of keratoconus.Post View 2 Comments
Keratoconus - Surgery
Did you or someone you know have surgery for keratoconus? Please relate your experience.Post
Top Keratoconus Related Articles
Astigmatism OverviewAstigmatism is an eye condition in which the cornea is abnormally curved and causes out-of-focus vision. Symptoms of astigmatism may include eye strain, squinting, eye fatigue, and headaches. Most astigmatism arised within the cornea although some forms occur in the lens. Astigmatism is diagnosed via a complete eye exam. Some cases of astigmatism can be treated with corrective eyewear. Astigmatism can also be treated with LASIK surgery.
Corneal DiseaseThe cornea is the clear outer layer of the eye. If it is damaged by disease, infection, or injury, vision problems may occur. Corneal problems can be detected by having an eye exam. Corneal problems can be prevented by protecting the eyes from injury and avoiding contact with people who have eye infections.
Eye CareMany common eye disorders resolve without treatment and some may be managed with over-the-counter (OTC) products. It's important to visit a physician or ophthalmologist is the problem involves the eyeball itself or the condition hasn't improved after 72 hours of use of an eye-care OTC product.
Eye Diseases SlideshowEye diseases can cause damage and blindness if not detected and treated soon enough. Learn the warning signs and symptoms of common eye conditions such as glaucoma, cataracts, pink eye, macular degeneration and more.
Keratoconus PictureWe see through the cornea, which is the clear, central part of the front surface of the eye. See a picture of Keratoconus and learn more about the health topic.
LASIK Eye SurgeryLASIK (laser in situ keratomileusis) eye surgery is a procedure in which a laser is used beneath the corneal flap to reshape the cornea. This process is used to:
- treat refractive errors,
- improve vision,
- and eliminate or reduce the need for contact lenses or glasses.
- conventional LASIK,
- wavefront-optimized LASIK,
- and wavefront-guided LASIK.