Keratoconus (also called corneal ectasia) is a degenerative disorder of the front dome of the eye (cornea). It is characterized by internal changes within the cornea that cause it to thin and thus lose its structural integrity. The result is that normal fluid pressures within the eye push out preferentially on the weaker areas of the cornea and cause it to bulge outwardly (usually irregularly) into a conical in shape. The consequences of this corneal steepening are usually a progressive increase in myopia (nearsightedness) and irregular astigmatism (oval or cone shaped cornea).
Keratoconus is estimated to occur somewhere between 1 in 500 to 1 in 2,000 people. It usually starts during late adolescence and progresses until about age 40. At that point, it slows down and sometimes frequently stabilizes. The causes of keratoconus are unclear but it is commonly seen among related family members. It occurs in both genders and races being slightly more common in females and among those with Asian heritage. Corneal ectasia, a form of keratoconus, can also occur as a late complication of refractive surgery like LASIK or PRK.
At the Cherry Creek Eye Physicians and Surgeons in Denver, Colorado, Dr. Lewis and Dr. Gray have been treating patients with mild, moderate and severe keratoconus for several years. They have both the experience and resources to offer a wide array of treatment options for each unique keratoconus case. Treatment must be customized to the individual patient.
Symptoms of Keratoconus
- The most common symptom of keratoconus or corneal ectasia is seeing multiple images – two or three fainter duplicates of the main image.
- Most people with keratoconus are also nearsighted (myopic) and astigmatic (meaning that the cornea is not spherical in shape, but more oval, or otherwise irregular).
- Some people have only mild symptoms, correctable with glasses or soft contact lenses. In fact, we have seen several patients who were unaware they had a vision disorder at all; they thought they just had “bad eyes.. Others have severe sight impairment that can’t be corrected with glasses or soft contacts.
Until recently, corneal transplantation was the only surgical treatment option for Keratoconus. However, an alternative procedure (Intacs) adapted from a well understood refractive one is available at Cherry Creek Eye Physicians & Surgeons. Intacs are tiny, plastic half ring segments that can be implanted into the corneal periphery. They help to flatten the corneal steepness, provide a strong, peripheral foundation for the cornea and reduce both myopia and astigmatism. This reversible procedure takes about 10 minutes per eye and is painless. Visual improvement occurs over the next few months with the goal of allowing patients to be fit more easily with less complicated, less expensive contact lenses and allowing most patients to be able to wear glasses.
When Glasses and Standard Soft or Gas Permeable Contacts are Ineffective
When keratoconus becomes moderate or severe, rigid contact lenses are frequently effective. We offer a variety of them:
- Scleral Gas Permeable Lenses – This lens comes in a variety of sizes and strengths (including toric or astigmatic-correcting lenses) and are popular when the patient has a more steep and abrupt corneal bulge (cone). These lenses (Zenlens) are large in diameter but quite comfortable because they vault over the corneal cone.
- Hybrid Lenses – These lenses (Synergeyes) have a rigid, breathable gas permeable lens centrally with a soft peripheral edge. They are good choices for patients who have off-center corneal steepening or who find they can’t tolerate a rigid lens.
- Gas Permeable KC lenses – These are gas permeable, custom-designed lenses. Examples are the Rose K, VIP Cone and the older Sopor lenses. They are best for patients who have worn rigid lenses successfully in the past.
- Soft KC lenses – This is a less rigid lens, for those with mild to moderate keratoconus who find rigid lenses too uncomfortable to wear. Examples are the Novakone, Soft-K and Specialeyes lenses.