Normally, in a healthy person, the cornea has a spherical shape. Keratoconus is a disease in which the cornea takes on a conical shape as a result of dystrophy and thinning of the tissue. Due to the conical shape of the cornea, the rays of light at its various points are refracted unevenly, so visual acuity decreases (as with myopia), a person sees objects distorted, lines broken (as with astigmatism). In advanced stages of keratoconus, thinning of the cornea (up to rupture) occurs, accompanied by pain. In most cases, keratoconus is manifested by decreased vision due to the development of astigmatism and myopia. Patients complain about the need for frequent changes in the optical power of glasses and intolerance to soft contact lenses.
Until recently, the only treatment for keratoconus was keratoplasty, a surgical operation on the cornea aimed at restoring its shape and function. This operation consists in replacing parts of the cornea with donor material. In Ukraine, the Excimer Ophthalmological Center was one of the first to use a new method for the treatment of keratoconus – corneal cross-linking.
What is the purpose of the cross-linking method?
The cross-linking technique was invented by Professor Theo Seiler. Cross-linking is the strengthening of the cornea and the stabilization of keratoconus using a special laser. In the course of such treatment, additional chemical bonds appear between the collagen fibers that form the structural framework of the cornea, which increase the mechanical density of the entire cornea. That is, new corneal fibers are formed, crossing each other. It becomes denser and can hold its shape, preventing further progression of keratoconus.
In the Eximer ophthalmological clinic, cross-linking for keratoconus is performed on a one-day basis. The procedure takes about an hour. The cost of the operation can be found in our contact center by calling the number listed on the clinic’s website.
Stages of cross-linking:
- Under general drip anesthesia, using special tools, the surface layer, the epithelium, is removed from the cornea.
- Within 30 minutes, every 5-10 minutes, riboflavin (vitamin B2 in a solution of dextran T500) is instilled into the cornea.
- Over the next 30 minutes, the instillation of riboflavin occurs simultaneously with the laser exposure to the cornea.
- After the operation, a protective contact lens is placed on the patient’s eye, which is removed after about 2-3 days. Over the next week, the patient should instill special drops for better recovery.
The use of the “cross-linking” technique makes it possible to strengthen the corneal stroma, stabilize the progression of keratoconus, stop the thinning of the cornea, and most importantly, prevent the need for corneal transplantation (keratoplasty).
It is now possible for patients with keratoconus and thin corneas to undergo laser correction at the same time as the cross-linking procedure to correct refractive errors. But the decision to conduct one cross-linking procedure or in conjunction with laser correction is made by the doctor based on the data obtained from the results of a complete diagnostic examination.