Treatment of keratoconus using the Corneal Cross Linking (CXL) method
Keratoconus is derived from Greek “kerato”, which means cornea, and “konos” meaning cone, bevel. Keratoconus is an eye disorder in which the usual spherical-cap shape of the cornea becomes conical in a certain part, which impairs vision. The progress of the disorder depends on the patient’s age and also its duration. The earlier the beginning of the disorder is, the faster the progress. Keratoconus usually affects both eyes, typically asymmetrically.
Keratoconus is a hereditary disease and it sometimes skips generations. It often starts at puberty and it is associated with allergies. Rubbing the eyes may quicken the progress of the disease.
At the onset of the disease wearing glasses is usually sufficient treatment. With the progress of the disease, the cornea becomes thinner and changes its shape, causing irregular astigmatism. This condition can no longer be corrected with glasses. Therefore the disorder of the cornea curvature is corrected by the insertion of air-permeable contact lenses. Although glasses and contact lenses correct vision, they do not have any influence on stopping the progress of the disease. The previous treatment consisted of a somewhat complicated, high-risk and costly cornea transplantation.
The principle of photochemical hardening of the cornea was invented by a German professor, Theo Seiler, now working in Zurich, Switzerland, where he taught Dr. Stodůlka the method in autumn 2006. Dr. Stodůlka is the author of the name of the CXL method which is now used internationally. Hardening of the cornea proceeds in two steps. At first the tissue is saturated with a yellow vitamin B2 solution and it is exposed to a special UV lamp providing radiation at a wavelength of 365 nm. The resulting chemical bonds harden the cornea without affecting its transparency. Thanks to this fact many patients can avoid transplantation and undergo the treatment of keratoconus which is much less invasive and much more safe. Dr. Stodůlka, Chief eye surgeon, was the first in the Czech Republic to combine the CXL surgery with a modification of the cornea shape by laser. During the surgery the shape of the eye is first treated by laser and subsequently hardened in a manner allowing its shape to be stabilized. We also combine the CXL method with implantation of corneal implants, so-called rings.
Accelerated corneal cross linking
In 2011 Dr. Stodůlka was the first in the Czech Republic to introduce accelerated corneal cross linking where the time of the surgery is reduced from 30 minutes to a mere three minutes. Gemini Eye Clinic uses the Avedro KXL device manufactured in the USA for this surgery. The surgery is executed within the framework of outpatient care and is not covered by health insurance.
Rigid Gas Permeable (RGP) contact lenses
Gemini Eye Clinic offers the application of RGP contact lenses (manufactured by Hecht Contactlinsen GmbH) at the clinic centre in Prague-Průhonice. Rigid contact lenses partly compensate the uneven shape of the cornea affected by keratoconus.
What are rigid contact lenses like and what are their advantages compared to soft contact lenses?
- personalized contact lenses (made to measure based on data received from the computerized videokeratograph)
- high permeability for oxygen
- very small dimensions (diameter of approx. 9.6 mm)
- very good exchange of tears under the contact lens
- high-quality vision
- no risk of the contact lenses drying
- very well tolerated long-time wearability
- less demanding in terms of maintenance
- easy handling
- service life 1 – 2 years
Rigid contact lenses preserve the eye physiology much better than soft contact lenses.
For whom are rigid contact lenses suitable?
- for those persons who wish to wear their contact lenses on a daily basis
- for those persons who wear contact lenses for over 10 hours a day
- for those persons who have any type of corneal astigmatism
- for those persons with an irregular shape of cornea (e.g. keratoconus, pellucid marginal degeneration, with corneal transplantation, with corneal injuries)