Keratoconus (KCN)

What is Keratoconus?

The word “keratoconus” comes from the Greek words “kerato,” which means cornea and “konos,” which means cone. Keratoconus refers to the progression of the cornea from a round to conical (cone-like) shape. The center of the cornea bulges out due to thinning of the tissue; the corneal tissue can thin to half of its original thickness.

Signs & Symptoms

With keratoconus the corneal surface becomes distorted, which can cause increased astigmatism, decreased vision, and sometimes scarring. Keratoconus typically occurs in both eyes, however one eye may have more severe symptoms.

Who has Keratoconus?

Keratoconus most commonly begins between the onset of puberty and the twenties. One out of 2,000 people in the general population are reported to have keratoconus. Keratoconus has not been associated with any particular social, cultural or geographical background.

Unfortunately, we do not know what causes keratoconus. A genetic basis has been speculated due to a higher familial pattern of occurrence than the general population; roughly one out of every 10 patients with keratoconus has family members who also have the condition. Some physicians are exploring the possibility of endocrine involvement, since the disease often occurs with puberty. Keratoconus may also be associated with other disorders, such as eczema. It is possible that rubbing the eyes contributes to the disease. One of the latest research efforts explores the relationship of keratoconus with the activity of certain enzymes in the eye. Although the causes of keratoconus may not be known, treatments for it are available.

Treatment

Contact lenses

Glasses and contact lenses may be equally effective for treating early stages of Keratoconus. Contact lenses are generally more effective than glasses as the condition progresses. Gas permeable contact lenses are usually used, but this depends on the patient. Fitting contact lenses in Keratoconus patients can be difficult due to the irregular shape of the cornea, and so multiple trials are often necessary; in some cases, contact lenses may need to be custom made. The lenses may feel uncomfortable (especially at first) or they may have a tendency to fall out of the eyes. Contact lenses are successful in 90% of those with Keratoconus.

Surgery

In about 10% of those with Keratoconus, corneal transplant surgery becomes necessary. Corneal transplants may be full-thickness (PK – Penetrating Keratoplasty) or partial-thickness (DALK – Deep Anterior Lamellar Keratoplasty). These surgical procedures have about a 95% success rate in Keratoconus patients. As with any surgical procedure, corneal transplant surgery has certain risks involved.

Collagen Cross Linking

Collagen Cross Linking is a procedure that promotes the strengthening of collagen in the cornea. With Keratoconus, the center of the cornea bulges out due to weakening and thinning of the tissue, and Collagen Cross Linking can help slow or stop this weakening. Collagen Cross Linking is performed in the office and takes 1-2 hours. Click here to read more.

The information contained within these pages is intended for informational purposes only and does not take the place of consulting a physician.
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Caring for your corneas since 1988