Keratoconus and Riboflavin UV-Crosslinking of the Cornea

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1 Keratoconus and Riboflavin UV-Crosslinking of the Cornea Institut für Refraktive und Ophthalmo-Chirurgie

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3 Dear patient, A keratoconus has been diagnosed on your cornea. In this disease, which affects 1 in 2,000 people in Switzerland, there is usually a progressive curvature change of the cornea, which impairs vision and, ultimately, so far has led to corneal transplantation with all the accompanying risks. In this brochure you will find information about keratoconus and the riboflavin UV-cross-linking of the cornea (cross-linking by UV light and vitamin B2) a treatment of keratoconus applied for the last 10 years. The cross-linking of the cornea is a method to stop the progressive curvature increase of the cornea in keratoconus. The results of a study over 10 years of follow-up are very encouraging and this innovative method is widely accepted as a standard treatment for keratoconus. The development of this method fits seamlessly into the maxim of IROC of achieving unique quality: - We have several years of experience in the field of eye surgery and our surgeons have performed more than operations. - One of our strengths is cooperation. The data collected regarding your eye is discussed within the team to ensure a best practice. We perform a risk/reward analysis and also take your life situation into account. - Due to our extensive experience, we have become more conservative and perform operations only if there is sufficient chance of success. We look forward to welcoming you to the IROC. Dr. med. Tobias Koller Dr. med. Michael Wolff Prof. Dr. med. Dr. rer. nat. Theo Seiler - 1 -

4 Keratoconus Frequency and causes Keratoconus affects 1 in every 2,000 people in our population. The causes of keratoconus are still largely unknown. It occurs more frequently within families, which indicates, among other things, an inherited cause. The only accepted reason, which represents a high risk for the emergence of keratoconus, is violent and frequent eye rubbing for years (e.g. for allergies). Symptoms Due to an increased weakness of the tissue, keratoconus causes increased bulging and protrusion of the cornea. As the cornea is the main component of the optics of the eye, this results in a variety of symptoms: changes in vision, decreased visual acuity despite correction with glasses or contact lenses, the perception of light rings around light sources ( halos ), and ghost images and increased sensitivity to light and glare. irregular astigmatism may be better corrected by contact lenses, as they exert pressure on the cornea and can compensate for the grossest irregularities. In this way, it is possible to have good vision in the initial phase of the disease with up to 100% visual acuity. However, if the curvature of the cornea continues to increase, there comes a time where even hard contact lenses can no longer be tolerated because they fall out frequently. With the increasing curvature, the cornea in the centre also gets thinner. It can crack and become scarred. This then reduces vision irreversibly. Time course We distinguish between a silent form of keratoconus, the so-called forme fruste and progressive keratoconus. Forme fruste: The forme fruste is up to 10 times more common than the progressive form. For the patient it generally produces fewer symptoms and is often indistinguishable from normal astigmatism. It is often discovered by chance during an eye test. In this case, you must only be followed by a doctor, but not treated when in a stable condition. Progressive form: This is aggressive and can be felt as early as during teenage years. With progression of the disease, the correction of vision with glasses is more difficult, because the curvature of the cornea is irregular. Such Left: distorted Placido image of keratoconus Right: Corneal tomography of keratoconus Previously, the only treatment option was to remove the diseased cornea and replace it with a donor cornea (corneal transplant). Such an operation is an organ transplant, with associated risks and complications, and adequate sight is often only achieved about two years after surgery. In addition, the corneal transplant in the case of keratoconus usually affects young people, who live with transplanted cornea for many decades, which means that the graft must function properly for decades

5 UV-riboflavin cross-linking of the cornea Diagnosis We have a variety of modern methods available by which we can find a keratoconus: Corneal imaging: This refers to a height map of the cornea, which can recognise a keratoconus in the inferior portion of the cornea. Corneal pachymetry: An ultrasound and optical examination of the corneal thickness shows thinning in the corneal area in the case of keratoconus. What is cross-linking? Cross-linking is a method for stabilising the mechanics and biochemistry of materials (tissues). Is cross-linking new in medicine? No. The cross-linking of tissues has been used in other branches of medicine (vocal cords, heart surgery) for many years. The application of cross-linking on the eye has only been routine for 10 years. Cross-linking of the cornea Cross-linking of the cornea is achieved by a combination of UV irradiation with administration of riboflavin eye drops (vitamin B2-drops). The intensity of the UV radiation is selected so that it does not damage the interior structures of the eye behind the cornea. The operation The operation can be performed as an outpatient procedure, takes a total of approximately 1 to 1.5 hours including preparation and is performed under local anaesthesia. In a first step, we remove the sealing layer of the cornea, the epithelium. This is necessary so that the riboflavin (vitamin B2) can pass into the cornea. Subsequently, the cornea is treated with UV light for minutes. At the end of the operation, we place a bandage contact lens on your cornea. This remains on the eye for a few days and is then removed by us. How does cross-linking work? Cross-linking results in an increased number of interconnections between the fibres of a tissue. This is similar to a network, which has the additional struts and is thereby more mechanically stable. The operation - 3 -

6 The aim of the operation The primary goal of surgery is to stabilise the curvature of the cornea, that is to freeze the current shape. In 40 to 80 % of treated eyes, there is a slight improvement (regression). Should a corneal transplant become necessary for some reason at a later date, this can always be performed After the operation Post-operation pain: The operation opens part of the corneal surface, similar to a welding hood or snow blindness. This causes some pain, which is normal for this type of operation. Do not be alarmed by the pain. It will subside slowly and tends to be virtually disappeared fter approximately 48 hours. We will give to you enough pain medication. Doctor s appointment: During the first 3 days after surgery, we are at your disposal, but the next regular inspection is carried out after 3 days to remove the contact lens. The eye is still treated for 3 weeks with anti-inflammatory eye drops. Risks and side effects Red eye: Your eye will stay distinctly red for about 2 weeks. This is normal and you should not worry. Scratching, itching and burning: can last for 6-8 weeks. To help alleviate the symptoms, we will prescribe artificial tears, which you can use as often as you like. Vision: Vision may be blurred more than before during the first 6 months after surgery. After this time you should have approximately the same visual acuity as before the operation. After one year, 40% of treated eyes were significantly better than before the surgery and about 1% of the eyes have worse vision. Glare from bright lights: Can be pronounced in the first months after surgery. Treatment failures: After one year, about 3% of the eyes show a persistent, albeit attenuated progression. Mostly, these are very advanced cases. For the next important check, you present again after 1 month. Until then, you may not use contact lenses in the treated eye. Further checks are performed after 6 and 12 months

7 Who is behind IROC? IROC, Institute for Refractive and Ophthalmic Surgery IROC was founded in summer 2002 and provides a unique association of eye-surgeons, physicists, laserdevelopers and opticians. Our team of surgeons represents more than 5 decades of academic experience in the field of the anterior eye-segment (a total of 20*000 interocular surgeries). Its our aim to sustain our unique quality standard and to make it accesible to our patients. Centre of competence With your decision of having your surgery made at our institute, you place yourself in the hands of your treating doctor. This requires a bond of trust. Our team at the institute for refractive and ophthalmic surgery offers far more than the secure handling of your treating doctor. We offer a service where not only your doctor is keen to fullfill his task, but our whole network of eye-doctors, eyesurgeons, opticians and physicists who are specialised in physiological optics. Such a combination of experts in different fields, who offer you the best possible comfort at the highest possible security, is unique in Europe. In addition we possess an experience of more than Lasersurgeries and are classified as a global centre of reference for other eye surgeons regarding very komplex cases of refractive surgery. The surgical Team of IROC Koller, Tobias Dr. med., medical studies in Zürich. Specialist registrar in Zürich and Stanford (USA), further education in anaesthesia, internal medicine and pathology. Further education in refractive surgery. Dr. Koller is reviewer for many internationals and has published more than 50 articles. Wolff, Michael. Dr. med., medical studies in Bonn (Ger). Specialist registrar in Düsseldorf (Ger) and London (UK). Further education in medical retina (London) and refractive surgery (Zürich). Seiler, Theo. Prof. Dr. med. Dr. rer. nat., medical and physics studies in Heidelberg and Berlin (Ger). Specialist registrar in Berlin. Full professor of ophthalmology and director of the university eye clinics of Dresden (Ger) and Zürich. Prof. Seiler has more than 30 years of academic experience. Furthermore, he developed PRK, customized ablation, cross-linking and published more than 200 scientific articles. He obtained many national and international awards in the field of ophthalmology

8 How to find us Contact information IROC AG Institut für Refraktive und Ophthalmo-Chirurgie Position and accessability IROC lies in the heart of Zürich. Its only a few steps away from the Bahnhofstrasse (Zürichs Approach By car: 2 Minuten from the Citycentre, 20 minutes from the Airport. By train: 20 minutes from the Airport. Stockerstrasse Zürich famous shopping street), the By tram: the trams 6,7,8 and Tel +41/(0) Fax +41/(0) info@iroc.ch lake, the hystoric district and the Fraumünster with its world famous Chagall-windows. 13 will take you to the stop Stockerstrasse, which only lies about 50 metres from our institute

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10 IROC AG Institut für Refraktive und Ophthalmo-Chirurgie Stockerstrasse Zürich Schweiz Tel +41 / (0) Fax +41 / (0) info@iroc.ch Patienteninformation Keratokonus Englisch, 10/ IROC AG