Until 2000, there were no treatments to stop so-called ectatic corneal diseases (keratoconus, PMD, keratectasia). As a result, there was nothing left but to wait until the cornea bulges so strongly that it was no longer possible to correct vision with glasses or contact lenses. At this stage, only a complex and high-risk corneal transplant could improve vision again.
Thanks to the invention of cross-linking by Prof. Dr. Dr. Theo Seiler, among others, there is a minimally invasive method to effectively stop the progression of these corneal diseases.
At EyePedia, we have extensive experience from many years of close cooperation with the inventor of corneal cross-linking.
The cornea of the eye consists of a framework of collagen fibers that are specially oriented. This arrangement creates a high level of stability and transparency, which is important for eyesight.
In patients with ectasia, this stability is reduced, causing the cornea to bulge ever further forward.
Through cross-linking, the collagen fibers are “cross-linked” and thus solidified. The primary goal of treatment is to stabilize the current shape of the cornea, i.e. to “freeze” it and prevent the progression of the disease.
The treatment takes place in four steps.
Cross-linking binds the collagen fibers together, which on the one hand increases stability and on the other hand also causes partial flattening.
The treatment itself is virtually painless and is performed under local anesthesia with anesthetic eye drops. After cross-linking, moderate to severe pain occurs, which subsides after two to three days. At first, vision is significantly reduced and sensitivity to glare is noticeable.
Returning to everyday activities and work is usually possible after 7-14 days.
In the last two decades, cross-linking treatment has been continuously developed. The output and duration of irradiation or the pattern of irradiation were optimised.
The irradiation time lasts 30 minutes with an energy of 3 mW/cm2
The irradiation time is reduced to 10 minutes during which the energy is reduced to 9 mW/cm2 Is increased. The treatment time is significantly reduced with a comparable cross-linking effect.
The radiation pattern is individually adapted to the patient's cornea or keratoconus. This reduces healing time and flattens out the bulging keratoconus more.
In less advanced forms of keratoconus, the cornea can be removed before cross-linking using a laser (PRK) Be leveled first. This regularization makes the cornea rounder again, which can later improve visual acuity without glasses or contact lenses.
Since the cornea can slightly flatten out to two years later due to the cross-linking effect, it makes sense to carry out laser correction later to improve visual acuity.
These protocols do not remove the top layer of the cornea (epithelium). This enables faster healing and less discomfort after the procedure. However, numerous studies have shown that the effect of this method is not sufficient, so we generally advise against these protocols.
With all types of cross-linking, the cornea is stiffened and flattened to varying degrees. In approximately 95% of treatments, the progression of keratoconus is stopped and the keratoconus partially regresses.
Immediately after treatment, a bandage contact lens is placed on the cornea. As a result, the epithelium (top layer of cornea), which is removed for treatment, can heal more quickly. To prevent the blink of the eye from slowing down the healing process, the eye is closed with an additional bandage.
The cornea is the tissue with the highest density of sensitive nerve fibers in humans. As a result, the body reacts to the treatment with increased lacrimation, severe burning and shooting pain.
Extensive pain management helps to make the first few days after treatment more pleasant:
The contact lens is carefully removed and it is checked whether the top layer of the cornea (epithelium) that was removed for treatment has healed. As soon as this is closed, eye drops (FML) containing cortisone are used to control the inflammatory response. The anti-inflammatory eye drops (FML) are slowly removed over four weeks.
In addition, we recommend using moisturizing eye drops (e.g. Optava AT/Lacrycon AT) regularly.
Vision recovers slowly, which can take up to several weeks.
With so-called OCT imaging (optical coherence tomography), it is possible to show what percentage of the cornea was successfully treated.
In the one-month check, the current topography is compared with the images before the operation. If the cornea is completely cleared, eye drops containing cortisone can be stopped.
Since the shape of the cornea is usually not completely regular even after cross-linking treatment, eyesight can only be improved to a limited extent with glasses. Shape-stable, i.e. hard, contact lenses cover the unevenness of the cornea and thus create a beautiful, spherical surface. This allows a sharp image to be created on the retina despite corneal deformation caused by keratoconus.
Further investigations are needed to rule out possible long-term effects such as scarring and inflammation in the area of the cornea.
In order to be sure that keratoconus has actually been stopped, further checks with topography measurements will be carried out in the first few years after treatment. Since the cornea can still slightly deform up to two years after cross-linking, it is possible that glasses or contact lenses may have to be adjusted more often during this time.
Since keratoconus is an inherited disease, it makes sense to examine the siblings and children of a person affected. The earlier cross-linking is performed, the better the prognosis for vision after the procedure.
In keratoconus, the cornea becomes thinner and bulges forward, making vision increasingly poor.
UV-A is the weakest type of UV radiation in natural sunlight and has the property that it cannot penetrate too deeply into human tissue. As a result of the interaction with riboflavin, the collagen fibers of the cornea are linked and thus stiffened.
Yes, those cross-linking techniques that do not remove the epithelium ((epi-on protocols) are significantly less effective, according to scientific publications.
Yes, using anesthetizing eye plugs to anesthetize the cornea. As a result, the treatment is almost painless. Pain only occurs after treatment.
The entire treatment takes approximately 45-60 minutes.
No Since Healing Takes Several Weeks and Is Not the Same for All Patients, We Usually Operate on the Eye in Which the Ectasia Has Progressed Further First. First, when the first eye has completely recovered, we treat the second eye.
Depending on the protocol used, the costs for cross-linking treatment vary between 1450.- and 3000.- CHF.
Yes, cross-linking treatment has been included in the health insurance provider's list of benefits. However, an application for reimbursement of costs is required before the operation. The prerequisite is proof that the disease is getting progressively worse (proof of progression)
Yes, these lenses are on the MiGeL (list of means and objects) Listed. The remuneration is usually not entirely sufficient to cover the costs of the specialist optician for the complex contact lens adjustment.
The biggest risk is a corneal infection in the first few days after cross-linking. However, this risk is minimized by administration of antibiotics after the procedure and is less than 0.1% for our patients.
Radiation rarely causes corneal opacities or scarring; these can be treated with eye drops containing cortisone. A reduction or even loss of visual acuity due to the CXL is rather unlikely.
The regular follow-up checks should, among other things, enable the early detection of corneal inflammation following cross-linking.
Keratectasia is a progressive disease and crosslinking can only stop it and not reverse it. This means that the earlier treatment is carried out, the better the end result will be.
As long as ectasia continues, your cornea will continue to thin and vision will continue to deteriorate. The probability that a corneal transplant will be necessary is increasing.
If keratoconus persists in childhood or adolescence, the risk of rapid worsening is particularly high and treatment should therefore be carried out as soon as possible. Young children need anesthesia by an anesthetist in a hospital. In this case, pain treatment after the procedure must be adjusted to the age and weight of the child.
