New methods of Keratoconus treatment available in Knezović Eye Clinic.
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Treatment of keratoconus in a specialized facility. Complete diagnostic work-up and counseling along with the Athens protocol procedure.
Keratoconus is a degenerative disease that affects the front surface of the eye called cornea. In patients suffering from keratoconus, progressive thinning, weakness and corneal irregularities lead to worsening visual acuity (shortsightedness and irregular astigmatism). There is a visual blur, appearance of ghost images and light sensitivity.
The exact cause of keratoconus is unknown, but is considered to be associated with poorer enzyme activity within the cornea. There is a genetic predisposition, as it is more common in families where keratoconus has already been diagnosed. Approximately, the incidence of keratoconus is one person per two thousand (5-8% in Down’s syndrome patients).
Unlike most other eye diseases keratoconus affects the younger population. It is often diagnosed with adolescents in their 20s. Younger age groups are the most endangered when it comes to disease progression, and if keratoconus is not treated, it can progress in 3rd and 4th life decades. It occurs equally in both sexes.
Keratoconus is very difficult to identify in the early stage without proper ophthalmic examination equipment (Pentacam analysis). The most common symptoms a patient can recognize are appearance of double-images, increased sensitivity to light and eye squeezing. Most people have the need to rub the eyes vigourosly and to squeeze the eye in order to sharpen the image, which may lead to progression of the disease itself. Keratoconus can also be recognized by the fact that after a while, glasses may not improve the visual acuity any more.
Keratoconus most commonly develops asymmetrically and in 90% of cases it affects both eyes. There are no rules on how the disease will progress, this differs from patient to patient. Keratoconus progression may take 10 to 20 years and in some cases may be life-long if not treated.
In most cases, contact lenses are prescribed, in order to sharpen the visual acuity and to allow patients normal participation in everyday activities. If keratoconus is not treated properly in time, it may progress until it causes permanent loss of vision and in some cases the only therapeutic option remains the corneal transplantation. Nowadays, there are less and less such cases due to advanced technology that allows diagnosis of keratoconus at an early stage. In our Clinic, keratoconus is successfully treated with the latest methods of Crosslinking (CXL) and the Athens Protocol.
If you have keratoconus, it is not possible to remove the diopter by standard methods, as this may lead to progression of the disease itself and decompesation of the cornea, which ultimately leads to a worsening of the visual acuity. If you want to correct your visual acuity (remove your diopter) and you have keratoconus, the best therapeutic option is the Athens protocol, which allows you to “take off the diopter” (actually regularizing cornea´s surface with few special laser procedures) as much as your corneal configuration permits it and also fix the cornea to stay stable after surgery.
Athens Protocol is a therapeutic procedure which goal is normalizing the corneal surface, i.e. to reduce the refractive error, irregular astigmatism and thus significantly improve visual acuity, and is particularly effective in halting the progression of keratoconus and avoiding the consequences of the disease.
The Athens Protocol for the treatment of keratoconus was first performed in Greece. Keratoconus is very successfully treated with this method. According to research of professor Kanellopoulos, the Athens Protocol, reduced the need for corneal transplantation in keratoconus in Greece for almost 90%.
The procedure begins with the initial“smoothening”of the corneal surface by laser treatment called phototherapeutic keratectomy (PTK), which removes the epithelium of the cornea.
The cornea is then subject to partial topographically guided (“topo-guided”) ablation (TGP). This procedure greatly reduces the microirregularities of the surface of the eye to a point that does not compromise the patient’s safety. Excimer laser is only treats thickness up to 50 micrometers to maintain the mechanical corneal structure, which is further firmed by corneal crosslinking (CXL).
Cross-linking has become a standard method for stopping keratoconus progression and various corneal ectasias (thinning), whether performed independently or as a part of the Athens protocol.
In addition to this, the advantage of this method is certainly a fact that it has shown good results in the treatment of infectious ulcers and other corneal diseases resistant to some of the standard treatment methods.
The goal of the procedure is to increase the degree of crosslinked collagen in the cornea to restore suitable mechanical stability. Currently, the exposure applied is 5.4 mJ / cm2 worldwide, with different irradiation levels of 3-30 mW / cm2.
So, the greater the irradiation, the shorter the duration of the procedure. Of course, this has its limits, because corneal cross linking is also dependent on the oxygen, which is necessary during the process itself and this requires a certain amount of time. This is why it is very important which UVA lamp and what type of riboflavin is used by the practicing physician.
In the Knezović Clinic we use a multifunctional UVA VEGA lamp to approach each patient individually. The time spent under UVA-light varies between 10 and 30 minutes.
• alcohol (very rare)
• by laser (Crete protocol)
• with Pallikaris’s surgical rotating brush
If the epithelium is not removed then it is EPI ON method – it is performed in special cases and in combination with other methods.
In the case of extra-thin corneas, we use the so-called “Contact lens assisted CXL” – a crosslinking method with a contact lens that is soaked with riboflavin (a special kind of lenses and riboflavin), thus allowing the method to be performed in very thin corneas. Interestingly, we are the first polyclinic in Europe to perform this procedure.
Since corneal cross-linking is different for each patient, especially if performed as a part of the Athens protocol, it is necessary to provide more types of riboflavin, to ensure adequately “soaked” cornea on one hand, and on the other hand, to have sufficient thickness and to preserve the deeper parts of the eye of unwanted effects of irradiation.
The threshold for photochemical damage caused by free radicals for endothelial cells is 0.35 mW / cm2. In all our interventions, the goal is to keep the aforementioned irradiation twice less this value, so the procedure is completely safe for the patient.
(ESCRS – European Society of Cataract and Refractive Surgeons) in Istanbul, 2015.
• Combined transepithelial phototherapeutic keratectomy and collagen cross linking using hypoosmolar riboflavin solution in progressive keratoconus management
*Remark
During the surgical procedure, the corneal thickness is monitored and, if necessary, certain parts of the protocol are changed, depending on the individual parameters. Prior to the procedure, UV lamp is once again calibrated with UV-meter. Irradiation for the treatment of keratoconus MUST be strictly controlled and homogeneous, without any “hot spots”, as this may lead to side effects.
From all of the above, it is obvious that corneal cross-linking, whether performed independently or as a part of the Athens protocol, is not a “one for all” procedure, but customized and algorithmically tailored procedure for each patient individually. Only with such an approach the patient may achieve maximum effect after the surgery, which can now be checked and estimated by the level of cross-linked collagen collagen fibers in the cornea.
The types of riboflavin (vitamin B2) we use in the Knezović Clinic:
• isotonic
• hypotonic
• transepithelial
• dextran enriched
• without dextran
• for contact lenses imbibition
The action combines PTK, TGP and CXL at the same time, thus achieving a synergistic effect that these three procedures performed separately do not achieve. The TGP procedure itself enables effective normalization of the corneal surface, which directly improves eyesight. If the TGP is performed after the CXL, the TGP operation partially suppresses the CXL efficiency. However, if the TGP is performed at the same time or just slightly before the CXL as in the Athens Protocol, it then allows for more penetration of riboflavin (and UVA rays) into the cornea, thereby achieving greater effect of covalent collagen bonding and significantly enhancing corneal strength due to enhanced cross-linking collagen fibers deeply in the cornea. In addition, combining these two procedures significantly reduces postoperative recovery time and patient˙s faster return to daily activities.
The Allegretto Eye Q laser platform – a prerequisite for the success of the project is the modern laser technology and the “secret recipe” – the nomogram database prof. Kanellopoulos
All steps are carried out under special control of top-level topographers, so-called Scheimpflug camera that does not allow excessive ablation and loss of tissue, which could harm the patient. Laser that performs Athens protocol is also great for wavefront optimized treatments of shortsightedness (up to -10 diopters), farsightedness (up to +6 diopters) and astigmatism (up to 5 diopters).
Pentacam – indispensable diagnostic tool for keratoconus
Oculyzer – Pentacam. The whole procedure is performed under the control of the Scheimpflug camera, so that remodeling of the tissue remains within the limits of the acceptable values.
After this procedure the cornea gets more regular contours, reduces the diopter, improves visual acuity and makes it easier to adjust to contact lenses if needed.
The whole procedure is painless, it is done in local anesthesia (drops, no injection) and with preparation of the patient lasts for about 2 hours.
According to research, the cornea after the Athens Protocol becomes 380% stronger and progression of the disease is reduced by 97%.
As a medical institution that has the greatest experience in the field of performing such and similar (topographically guided) procedures, we can express our satisfaction with excellent results after the Athens Protocol.
Presentation by Dr Knezović About the ATHENS PROTOCOL at the International Congress of the European Society of Cataract and Refractive Surgeons in London,
Topographic-guided excimer laser treatment: Corneal epithelial basement membrane dystrophy (EBMD) with phototherapeutic keratectomy (PTK 90 microns and ‘wet PTK’) and wavefront-optimized photorefractive keratectomy (PRK)
First Author:: I.Knezovic
Most of our patients see significantly better after the Athens protocol, some of them even so much better that they even no longer need glasses or contact lenses. This is impressive because most of them would see progressively worse, would only be suggested to wear RGP contact lenses (which may sometimes aggravate the condition in the progression phase) or they are suggested only cross-linking (epi off method) which does not significantly improve visual acuity.
Below are some topographic pictures of some of our patients. The left picture shows the corneal surface before the procedure, in the middle is the image after the procedure (significantly improved form!), and the right hand side is the image showing the ablation profile, i.e. the laser correction / regularization treatment.
These results were presented at several professional meetings in Croatia and abroad and published in the form of an original scientific paper in the journal Acta Clinica Croatica.
PATIENT 1.
PATIENT 2
PATIENT 3
With the Athens Protocol, more accurate contours are achieved, refractive error is reduced, visual acuity improved and it is easier to fit the contact lenses if they need to be worn after the surgery while with cross-linking only – the cornea is strengthened but these other effects are not achieved.
Athens Protocol – Patient Experience
The entire procedure is completely painless, it is done in local anesthesia (eyedrops, without injection). The complete procedure with the preparation of the patient lasts about 2 hours (for one eye). During the procedure the patient is awake and communicates with the surgeon all the time. Immediately after the procedure a therapeutic lens is placed on the cornea and it serves as a protection and it helps corneal surface to heal faster. After the procedure, the patient gets all the necessary therapy and goes home where he has to rest and avoid any adverse conditions until the first check-up, scheduled 3 days postoperatively.
Three days after surgery, most of the patients return to their daily activities. If you work in unfavorable microclimate conditions (wind, dust, smoke) it is desirable to stay home for the next 7 to 10 days. The cornea may change during the first year due to vitamin supplements and collagen fixation until it gets its final shape. If necessary, 1-2 months after the procedure the contact lenses may be prescribed for the best visual acuity.
Is it possible to have surgery on both eyes the same day?
It is not advisable to operate on both eyes the same day. It is always advisable to perform the procedure on a worse eye first (the one on which the disease progresses faster), and after the first eye is recovered, it is possible to do the operation on the other eye. If it is needed to perform the urgent surgery of the other eye – this can be done in 1-2 weeks after the first eye surgery has been performed. Likewise, if there is no urgent need for the other eye, the time between the two surgeries can be done even after a longer period when the first eye has healed completely.
Thanks to the advanced laser technology that makes it possible to properly do the procedure and special nomograms constructed by Dr. Kanellopoulus’s for many years of work and personal friendship and collaboration between Dr. Knezovic and Prof. Kanelopoulus, patients no longer need to go to America or Athens. Just sign up and check out our Clinic.
The data of each patient is personally analyzed by Dr. Knezovic, who has carried out over 1000 Athens Protocols in his career, and is therefore visited by patients from all over the Europe.
If you have a problem with an poor or unstable vision, keratoconus or someone in your family has had similar problems, you are a good candidate for this type of specialist examination.
Many years of experience and state-of-the-art technology are available in Zagreb at the Knezović Vision Group Clinic, Ulica grada Vukovara 269f, tel. 01/66 77 222.
For all the questions fell free
to call us 01 / 66 77 222
Poliklinika Knezović
Green Gold Business Center, Tower V1, 8th floor
Ulica grada Vukovara 269f
10000 Zagreb
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