Skip to content

FDA approved CXL cornea crosslinking for Keratoconus eye disease

Corneal Collagen Cross-linking with Riboflavin and UVA
Keratoconus is a distressing disease as it affects younger people. Early management includes; glasses, toric contact lenses. In more advanced cases specialized hybrid contact lens are helpful. Intacs can help advanced cases and contact lenses intolerant patients. None of these techniques halt the progression of the disease. For the first time there is hope that the progression of this relentless monster may be slowed or halted.  The savior is corneal crosslinking. Crosslinking technology has been used in the field of biotechnology for prosthetic heart valves. What it essentially does is increase connections between different layers of cornea. The interweaving of the collagen fibers yields strength to the cornea. This increases stability. When riboflavin is instilled over the cornea which has been denuded of epithelium, it penetrates the stroma.  UV light is absorbed by riboflavin and gets excited to it’s Triplett state which produce reactive oxygen species like; hydrogen peroxide, superoxide and singlet oxygen.
The cross linking procedure involves;
1 First calibrating the UV device
2 The patient is provided with anesthesia
3 The speculum is then inserted
4 5 minutes prior to the UV procedure the patient is given a drop of riboflavin administered through the cornea.
5 The epithelium is removed so that riboflavin can gain uniform access to the stroma of the cornea.
6 The procedure takes approximately 30 minutes; riboflavin is distributed thoroughly throughout the duration of the procedure.
7 The patient is to the slit lamp and the distribution of riboflavin is conformed by noting flare in the anterior chamber.
8 During the procedure the UV light is applied and further riboflavin is applied every few minutes.
9 At the end of the procedure a bandage contact lens is applied along with antibiotic and steroid drops.
The effect of riboflavin is to create reactive species which cause the various layers of collagen fibers to develop new love (bonds) with each other. This makes the cornea stiffer and more resistant to intraocular pressure. In physics’ terms young modulus is increased (young modulus is equal to stress over strain). This has been studied and demonstrated in lab studies.
The effect of cross-linking can be seen on corneal imaging where the treated area appears more dense in fact sometimes a demarcation line can be observed between the untreated and treated areas. Clinically the stability in eye refraction and the shape on corneal topography can be observed over the next few years. Corneal cross-linking may also be combined with intacs treatment. It can be done at the same sitting or cross-linking can be done 3 to 6 months after intacs have been inserted and the cornea has stabilized.
Currently the cross-linking is being undertaken as part of FDA approved study. In Europe the cross linking has been performed safely and effectively for many years. When ever new technology is introduced into the United States Khanna Institute is careful to evaluate it along with the FDA. By passing the FDA and using new technology is not considered good medicine. If you are suffering from keratoconus and would like to avail of cross-linking please call Khanna Institute to enroll in this study.