Keratoconus is a condition that develops when the clear covering of your eye, called the cornea, assumes a dome shape instead of the relatively flat curve it normally has. In a normal, healthy cornea, light enters through the cornea before passing through the clear lens of the eye, located just behind the iris. The lens focuses the light on the light-sensitive cells of the retina, located at the back of the eye. Images that are focused correctly appear crisp and clear.
But when the cornea is misshapen and “dome-like” as in keratoconus, light is bent as soon as it enters the eye; light becomes scattered, triggering cells in different portions of the retina and resulting in blurry vision and sometimes glare and light sensitivity.
Keratoconus usually begins between the ages of 10 and 25 years, and it often progresses slowly over a period of about 10 years. Sometimes, though, the cornea lining will break down, allowing fluid to enter the cornea and causing rapid swelling that can result in scarring and permanent vision damage.
WHAT CAUSES KERATOCONUS?
The specific cause of keratoconus isn’t known, but researchers have identified risk factors that increase the chances someone will develop the condition. These risk factors include:
- family history of keratoconus
- personal history of certain diseases and health conditions, including asthma, allergies, retinitis pigmentosa or Down syndrome
- repeatedly rubbing the eyes too hard or vigorously
A few studies have suggested hormonal changes or oxidative stress may also play a role in the development of keratoconus.
Although family history or genetics has been advanced as a primary risk factor, most people who develop keratoconus do not have family members with the condition; in fact, there’s a less than 1-in-10 chance that someone with keratoconus has a blood relative with the condition., according to the National Keratoconus Foundation. Routine dilated eye exams are the best way to monitor for the presence of irregularly-shaped or domed corneas.
Keratoconus is diagnosed with a comprehensive eye exam using special techniques to evaluate the structure or the eye and to check for any signs of deformation of the cornea. One such evaluation uses a small circle of light which is projected onto your cornea to look for aberrations in the way the circle appears. Computerized corneal mapping may also be used to create a topographical map of the corneal surface and to measure the thickness of your cornea. Dilated examination with a special lighted instrument called a slit-lamp is also performed to look for other conditions that could also be contributed to vision loss and eye health issues.
KERATOCONUS TREATMENT OPTIONS
Treatment of keratoconus depends on how far the disease has progressed. In patients with mild to moderate keratoconus, wearing special contact lenses or glasses may be all that’s needed to correct vision problems and enable the cornea to stabilize over time. Contact lenses should be carefully fitted by an eye care professional with experience in fitting lenses for keratoconus treatment. If the cornea becomes scarred or very thin, or if lenses don’t provide enough correction, surgery may be recommended.
Keratoconus surgery typically takes two approaches:
- Corneal insert surgery uses tiny, crescent-shaped inserts called intracorneal rings to help flatten out the cornea, restoring it to a more normal shape so vision is improved and “bulging” is prevented or slowed.
- Corneal transplant surgery (also called keratoplasty) removes either all of your cornea or just a portion and replaces it with healthy donor tissue. Transplants are usually only performed in patients with extremely thin corneas or those with very badly scarred corneas.
Studies have indicated that many people with keratoconus have corneas that lack certain very fine fibers, called fibrils, that link together to help anchor and stabilize the cornea. Without these fibers to hold the cornea in place, the cornea can become more flexible and “lax,” enabling it to bulge outward and assume its characteristic dome- or cone-shaped appearance. As a result of these studies, a novel form of keratoconus called corneal cross-linking his being evaluated. In this treatment, special eye drops are placed in the eye, which is exposed to measured doses of UVA light. The drops and light work together to help promote stronger bonds inside the cornea to help stabilize it.
GETTING THE TREATMENT YOU NEED
At Sealy Eye Center, our eye care specialists use the latest technology to diagnose and manage keratoconus in patients from Sealy and through the the Houston–The Woodlands–Sugar Land metropolitan area. Each treatment plan is carefully developed based on a comprehensive assessment of individual health needs, medical histories and other factors to ensure the most appropriate and effective care for optimal vision outcomes. Routine eye exams are critical to maintaining vision health at every age. Call Sealy Eye Center at (888)701-7487 today to schedule your exam.