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Status: Ready for the Market

Radiation facility for the treatment of the eye disease keratoconus

KERALUX is the latest and most effective crosslinking technology for the treatment of keratoconus. The aim of the crosslinking method is to prevent disease progression and avoid de facto blindness. The cornea is mechanically strengthened by crosslinking the collagen fibres of the tissue in order to rectify the tissue weakness of the compromised cornea. To this end, the cornea is exposed to UV radiation with defined energy and wavelength. Prior to the procedure, a photoactive substance (riboflavin) is introduced into the cornea to facilitate the crosslinking of collagen by means of radiation.

Unfortunately, the conventional technology is burdened by a high treatment failure rate. KERALUX in turn avoids the treatment errors of the conventional technology caused by eye and head movements, by distance variation between the cornea and the radiation source, and by the curved and variable corneal geometry. Treatment with KERALUX is also quick and easy to perform in a private practice. KERALUX is a revolutionary and internationally patented technology which for the first time ever facilitates an optimised and defined energy transfer to the compromised cornea. For patients who are anxious, restless and unwilling to cooperate, KERALUX is the only crosslinking treatment option available. Unlike the large, impractical and expensive devices used by the conventional technology, KERALUX is a miniaturised disposable device for single use that can be applied easily, anywhere and anytime, allowing an optimised and automated treatment procedure thanks to its high-end microelectronics in monitored battery operation. KERALUX has already been approved as a medical device in the EU and has been successfully used in routine applications on humans for more than three years. Thanks to its highly innovative micro-technology and compact design, KERALUX is easily portable and can be used everywhere at any time. This makes it perfectly suitable for online sale, without the need of intermediaries. Despite its built-in cutting-edge technology, it is a relatively inexpensive device for single use, where physicians don't have to make high investments nor calculate payback periods. In contrast to the conventional standard procedure where the patient is exposed to radiation for about 30 minutes, the standard version of the KERALUX technology is designed for a radiation exposure of merely 10 minutes with the same energy output. KERALUX is not only the perfect product for private practices with low case figures; also clinical care centres with large patient numbers will medically and commercially benefit from KERALUX over the large, cumbersome and expensive conventional technology. KERALUX allows one physician and his team to treat several patients at a time, or even both eyes in one patient at the same time.


In Europe, between 1 out of 2000 inhabitants and 1 out of 1000 inhabitants suffers from keratoconus. In other regions of the world, this disorder is even more common. Especially in the Near East/Middle East, its frequency is in the single-digit range, and in endemic areas sometimes even in the double-digit range. As diagnostic methods improve, the relative incidence rate among the population in industrialised countries is increasing. The crosslinking technique is used to prevent disease progression and avoid de facto blindness. Treatment should therefore be initiated early, ideally at the onset of the disease, when visual acuity is still relatively good. The age when the first symptoms occur is usually between 10 and 30 years. The disease often deteriorates rapidly in the teenage years, so that patients are often already de facto blind before they reach the age of 20. Unfortunately, the stabilising effect of the crosslinking technique often lasts only 5 years and then has to be repeated.

Based on the epidemiological figures, the number of treatments requiring medical treatment can be estimated as follows:

Conventional crosslinking

Conventional crosslinking is burdened by a high treatment failure rate, which causes the disease to progress despite treatment. Eye and head movements, distance variations between the radiation source and the cornea during conventional treatment, but also the corneal geometry prevent an adequate transfer of energy to the cornea. To understand this issue correctly, one has to imagine a house with a solar system installed on the roof for use of solar energy. The energy transfer will only be optimal when the solar panels are positioned at the right angle facing the sun. If the solar panels face the sun at a narrow angle, the energy output will not be optimal. In conventional crosslinking, there is also a free radiation path towards the cornea, similar to the sun. The problem now is that the cornea, which needs to absorb the radiation for maximum effect, is curved and can therefore not be aligned with the radiation source. As a result, the energy transfer to the cornea is only optimal at its ‘tip’. Keratoconus further exacerbates the problem. Compared to a healthy cornea, a keratoconic cornea has a much steeper angle and is also irregularly curved. A correct and defined energy transfer to the cornea, which would be needed to treat the disease, simply does not work in conventional crosslinking. Radiation has the least effect in the spot where the cornea bulges outward and has the steepest angle.

KERALUX Crosslinking

The KERALUX technology solves all the typical problems and error sources of conventional crosslinking in an impressively simple and comprehensible manner. Instead of a free radiation path as in conventional crosslinking, where it is impossible for a patient to keep the eye and head accurately in place and to keep the exact distance from the radiation source for several minutes, let alone for 30 minutes, the radiation source of KERALUX is fixed to the eye via a closed radiation channel. This assures that the system moves in sync with each eye and head movement, thus eliminating errors caused by head and eye movements as well as problems caused by distance variations between the cornea and the radiation source. What is more, the radiation beam is directed into the radiation channel in a slightly divergent fashion, so it hits the interior wall of the channel which is lined with a diffusely reflecting layer. This causes the radiation to reach the cornea from all directions and the geometry of the cornea doesn’t matter anymore. Unlike conventional crosslinking, KERALUX ensures an optimal and correct treatment energy transfer (5.4 J/cm2) at all times and at every single point of the cornea, regardless of the patient's corneal geometry.


[Translate to English:]

Wavelength 365 nm ± 10 nm
Energy 5.4 J/cm2
Radiation continuous
Irradiation diameter 7 mm to 11 mm
Voltage source

no external voltage needed (battery)


height 90 mm, diameter 24 mm



Scientific literature

1. Fratzl P, Daxer A (1993) Structural transformation of collagen fibrils in corneal stroma during drying: An X-ray scattering study. Biophys J 64:1210-1214.

2. Huber M, Gröbner J, Daxer A, Blumthaler M, Ambach W (1994) Erste Untersuchungen der Transmission der Hornhaut des humanen Auges im Hinblick auf die Photorefraktive Keratektomie. Z Med Phys 4:211-212.

3. Ambach W, Blumthaler M, Schöpf T, Ambach E, Tributsch W, Daxecker F, Daxer A (1994) Spectral transmission of the optical media of the human eye with respect to keratitis and cataract formation. Doc Ophthalmol 88:165-173.

4. Daxecker F, Ambach W, Blumthaler M, Schöpf T, Ambach E, Tributsch W, Daxer A (1995) Spektrale Ultraviolett-Transmission des menschlichen Auges. Spektrum Augenheilkd 9:80-84.

5. Daxer A, Fratzl P (1997) Collagen fibril orientation in the human corneal stroma and its implication in keratoconus. Invest Ophthalmol Vis Sci 38:121-129.

6. Daxer A, Misof K, Grabner B, Ettl A, Fratzl P. (1998) Collagen fibrils in the human corneal stroma: structure and ageing. Invest Ophthalmol Vis Sci 39:644-648.

7. Daxer A, Blumthaler M, Schreder J, Ettl A. (1998) Effectiveness of Eye Drops protective against Ultraviolet Radiation. Ophthalmic Res 30:286-290.

8. Schreder JG, Blumthaler M, Daxer A, Ettl A (1998) Absorbtion von Chibro-Uvelin Augentropfen für UV-Schutz. Z Med Phys 8:150-152.

9. Vryghem JC, Coskunseven E, Daxer A, Kanellopoulos AJ, Nuijts RMMA (2009) Surgical Visual Rehabilitation Techniques. Cataract & Refractive Surgery Today Europe 4:60-68.

10. A. Daxer, H. Mahmoud and RS Venkateswaran (2010). Corneal cross-linking and visual rehabilitation in keratoconus in one session without epithelial debridement: new technique. Cornea 29:1180-1185.

11. A. Daxer (2018) A disposable UV-A Crosslinking technology for optimized energy transfer to the cornea. International CXL Congress Zurich.

12. Barbara Daxer, T Budic, C Tomschi, A Ettl (2019) Clinical experience with a novel UV-A irradiation system for crosslinking treatment in keratoconus. Congress of the European Society of Cataract and Refractive Surgeons (ESCRS) in Paris.