Keratoconus is an eye disease that concerns the cornea. The cornea is a thin, clear tissue covering the surface of the front of the eye.
It is a very important contributor to our vision, accounting for 2/3 of the eye’s optical power. A normal, healthy cornea holds its round shape and helps us see.
But sometimes the cornea becomes structurally weakened and loses its shape. Instead of a dome, it becomes cone-shaped, prohibiting clear vision. This is known as keratoconus.
Causes of keratoconus
The cause of keratoconus is unknown. Some research shows that keratoconus may run in families and may affect those with allergies more often. Other research suggests too much eye rubbing can cause keratoconus. Although it is not proven that eye rubbing can exacerbate keratoconus, it is probably a good idea to keep from rubbing the front of your eye too much anyway, as it is a delicate part of the body.
Most of the time, there is no eye injury or disease that provokes keratoconus. If you develop keratoconus, you were probably bound to develop it from birth. Keratoconus is most prevalent in those who are near-sighted.
There are no preventative measures for keratoconus, but if you develop it, there are many treatment options available.
Onset and Treatment
Keratoconus usually develops early, in the teenage years and twenties, but it can begin even earlier, during childhood.
It will most likely present in a patient before age 30. Keratoconus can progress for 10-20 years and then slow down considerably as the patient ages.
The first symptoms of keratoconus are blurred vision and increased sensitivity to light. At first, you may be able to wear soft contact lenses or eyeglasses to correct the mild near-sightedness and/or astigmatism caused by keratoconus.
Eventually keratoconus may progress so far that glasses cannot correct your vision.
Usually keratoconus can be corrected over a lifetime using rigid gas-permeable contact lens and regular check-ups. In advanced cases, the cornea wears down at the very point of the cone shape. If this happens, you may need to undergo a corneal transplant. Recovery from this surgery can take a long time, but the risk of the body rejecting a transplanted cornea is very low. Most often, patients will still need to wear contact lenses after the surgery.
There are a few different options to prevent the need for a corneal transplant:
• Intrastromal corneal ring segments: a surgical procedure where small implants are inserted into the eye to correct vision.
• Mini asymmetric radial keratotomy: a controlled scarring of the cornea by administering a careful pattern of incisions. Scar tissue develops around the incision points and reshapes the cornea.
• Corneal cross-linking: a method where custom riboflavin eye drops are activated by ultra-violet light over a 30-minute session, meant to increase collagen cross-linking in the cornea and thereby strengthen it.
To test for keratoconus, your eye doctor will check for distorted vision, blurred vision of objects (both near and far), sudden changes in one eye’s vision or double vision when using only one eye and halos around bright lights.
Keratoconus can be diagnosed by examination. A slit-lamp examination may be performed. A slit-lamp is a kind of low-power microscope that shines a bright beam of light into the eye. This examination can be used to detect many eye diseases and problems, including corneal injuries, cataracts and macular degeneration (a disease of the macula, the part of the eye that allows you to see fine details).
Another type of examination called corneal topography can be performed using computerized instruments to create a map of the cornea. This is an advanced technology and offers the most complete view of your cornea.
If you are considering corrective laser eye surgery, it is imperative you do not even have borderline keratoconus. Corneal topography will be performed on any patient seeking LASIK treatment to make sure they do not have keratoconus before scheduling surgery.
Although there are no specific ways to prevent keratoconus, some basic lifestyle choices can help keep your eyes healthy.
• Regular eye examinations are a must. It is during these exams that your health care provider has a chance to detect any conditions like keratoconus before they become a bigger problem. Once a year check-ups are instrumental in maintaining health vision over your lifetime.
• Wearing sunglasses to protect your eyes is an easy way to guard your vision against UV damage.
• A healthy lifestyle keeps your blood pressure, cholesterol and blood sugar in balance. Suggestions include no smoking, limited alcohol consumption and lots of leafy, green vegetables high in antioxidants.
When to see a eye care professional:
If your child or teenager has vision problems that cannot be corrected to 20/20 with glasses, they should be evaluated by a eye care professional with experience in diagnosing and treating keratoconus.
Always see your eye care professional immediately if you have any sudden changes in vision. This includes darkening around the edges of your vision, dark spots in front of your eyes, halos around bright lights, a loss of vision in one part of your field of sight or any other noticeable change.