Friedrich-Alexander-Universität Erlangen-Nürnberg

Development of system technology for corneal fs-laser surgery

Development of system technology for corneal fs-laser surgery

Corneal laser refractive vision correction of the human eye is a common operation nowadays. The state-of-the-art method for corneal laser surgery is the so-called Laser assisted in-situ Keraomileusis (LASIK), carried out appr. 10 million times p.a. worldwide. In this treatment the cornea is cut using a femtosecond laser (acting as thin, precise scalpel) in such way that a thin layer of the cornea, the so-called ‘flap’, can be lifted and folded back revealing the corneal stroma. Subsequently the excimer laser processing and thus refractive correction can be carried out by reshaping the cornea through vaporization of tissue. After tissue ablation the flap is put back in its original position, acting as a natural bandage of the wound.

The technology for the flap cut and the refractive correction requires an arrangement of leading-edge opto-mechanical components for both the femtosecond laser and the excimer laser in order to meet patient’s high expectations regarding safety and predictability of the procedure.

Within the project, a novel alternative to LASIK is studied, offering higher precision of the visual outcome as well as lower impact on the biomechanical structure of the cornea. To further reduce treatment time and increase correction accuracy novel system technology is developed. The first main aim is to increase laser pulse repetition rate of the femtosecond laser to decrease treatment time. This requires accordingly fast beam steering (i.e. laser scanning) and real-time focus quality and position control. Novel femtosecond laser technology is characterized as well as novel scanning technology, such as KTN-scanners, AOD-scanners and others. In addition fast focus shifters are studied and characterized. The second main aim is to assure perfect focal beam profile under all possible treatment conditions.


SAOT provides an interdisciplinary research and education program of excellence within a broad international network of distinguished experts to promote innovation and leadership in the areas

Optical Metrology
Optical Material Processing
Optics in Medicine
Optics in Communication and Information Technology
Optical Materials and Systems
and Computational Optics.