What is Keratoconus?
Keratoconus, often referred to as ‘KC’, is a non-inflammatory eye condition in which the typically round dome-shaped cornea progressively thins and weakens, causing the development of a cone-like bulge and optical irregularity of the cornea. This causes ‘static’ in your vision and can result in significant visual impairment.
Keratoconus typically first appears in individuals who are in their late teens or early twenties, and may progress for 10-20 years, and then slow or stabilize. Each eye may be affected differently. In the early stages of keratoconus, people might experience:
- Slight blurring of vision
- Distortion of vision
- Increased sensitivity to light
The cornea is responsible for focusing most of the light that comes into the eye. Therefore, abnormalities of the cornea, such as keratoconus, can have a major impact on how an individual sees the world, making simple tasks such as driving a car or reading a book very difficult.1
- Can result in significant vision loss; and
- May lead to corneal transplant in severe cases
You can find more information from the National Keratoconus Foundation at www.NKCF.org
What is Corneal Cross-Linking?
Cross-linking is a minimally invasive outpatient procedure that combines the use of UVA light and riboflavin eye drops to add stiffness to corneas which have been weakened by disease or refractive surgery. Cross-linking, which has been performed in Europe since 2003, is considered the standard of care around the world for keratoconus and corneal ectasia following refractive surgery2.
- Creates new corneal collagen cross-links
- Results in a shortening and thickening of the collagen fibrils
- Leads to the stiffening of the cornea
Less Cross-Linking (Weaker) More Cross-Linking (Stronger)
Riboflavin (vitamin B2) is important for body growth, red blood cell production and assists in releasing energy from carbohydrates. Its food sources include dairy products, eggs, green leafy vegetables, lean meats, legumes, and nuts. Breads and cereals are often fortified with riboflavin.
Under the conditions used for corneal collagen cross-linking, riboflavin 5’-phosphate, vitamin B2, functions as a photoenhancer which enables the cross-linking reaction to occur.
Ultra-Violet A (UVA)
UVA is one of the three types of invisible light rays given off by the sun (together with ultra-violet B and ultra-violet C) and is the weakest of the three.
A UV light source is applied to irradiate the cornea after it has been soaked in the photoenhancing riboflavin solution. This cross-linking process stiffens the cornea by increasing the number of molecular bonds, or cross-links, in the collagen.
Is Cross-Linking Right for Me?
Patients over the age of 14 who have been diagnosed with progressive keratoconus or corneal ectasia following refractive surgery should ask their doctor about corneal cross-linking.
Our practice is proud to offer patients in our practice the first and only therapeutic products for corneal cross-linking which have been FDA approved to treat progressive keratoconus. This approval offers an effective treatment for patients who, until recently, had no therapeutic options to limit the progression of this sight-threatening disease.
For information on the FDA approved corneal cross-linking procedure for the treatment of keratoconus and corneal ectasia following refractive surgery, visit www.Avedro.com.
- National Keratoconus Foundation
- Gomes, José A. P., Donald Tan, Christopher J. Rapuano, Michael W. Belin, Renato Ambrósio, José L. Guell, François Malecaze, Kohji Nishida, and Virender S. Sangwan. “Global Consensus on Keratoconus and Ectatic Diseases.” Cornea 34.4 (2015): 359-69. Web.
- Beshwati IM, O’Donnell C, Radhakrishnan H Biomechanical properties of corneal tissue after ultraviolet-A-riboflavin crosslinking. J Cataract Refract Surg. 2013;39(3):451-62. Doi:10.1016/j.jcrs.2013.01.026.