Keratoconus is a disorder in which the cornea, the clear window of the eye, undergoes progressive thinning and bulging. It affects 1 in 2000 individuals.
Signs and Symptoms
Keratoconus is bilateral, but one eye may be affected more than the other. The condition first appears in late teens and early twenties. Although it can stabilize, many cases can continue to progress. The first symptoms of keratoconus include blurry vision, ghosting or doubling of images, and poor night vision. Majority of the patients have thin corneas and are nearsighted with high astigmatism.
The exact cause of keratoconus is unknown and likely multi-factorial. There is a genetic component with a positive family history in 6-8% of the cases. There is an association with eye rubbing and incidence of keratoconus.
Diagnosis of keratoconus starts with detailed patient and family history followed by a complete eye examination. An important step in the diagnosis is a computerized topography, which takes a digital map of the curvature of the cornea. Patients with keratoconus show an inferior corneal steepening and thinning.
Mild cases of keratoconus can be corrected with glasses. In more advanced cases, hard or gas-permeable contact lenses can be a better option. These lenses help neutralize the irregular astigmatism in the cornea and produce a noticeable improvement in vision. Some patient can be intolerance of contact lenses due to the shape and the degree of corneal steepening. Implantable intracorneal rings, called Intacs, can help some of these patients back into contact lenses.
Intacs are semicircular rings that are surgically implanted under the outer edge of the cornea. These implants help reshape the cornea and decrease some of the steepness of the condition. Intacs do not stop the progression of keratoconus. They reshape the cornea to help patients become more tolerance of contact lenses. When Intacs and contact lenses are no longer satisfactory, especially in advanced cases with corneal scars, patient may need a corneal transplant.
Corneal transplant involved replacement of the central part of the cornea with a donor cornea. The procedure involved removal of a circular button from the center of the cornea followed by suturing of a similar size button from a donor cornea. The sutures are removed over period of time leaving a clear corneal with improved visual quality. There are newer treatment options for keratoconus in the FDA approval process. One of these treatments is corneal collagen cross-linking.
Corneal cross-linking involved application of riboflavin (also known as vitamin B2) to the eye followed by exposure to ultraviolet light. The ultraviolet exposure causes linking of riboflavin molecule with the microstructures of the cornea. This cross-linking has been shown to increase corneal rigidity and decrease the progression of keratoconus. This exciting new treatment is currently in FDA clinical trials to determine its efficiency and safety before approval.
To learn more about keratoconus, please call 800.527.3745 to make an appointment to see one of our specialists at LaserVue Eye Center.
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