Search

Purpose We realized an innovative device for ocular surgery by ultrafast pulse laser optimised for corneal grafting. Methods We constructed a demonstrator device that reproduces surgical conditions of corneal transplant. It is thus possible to realize with the help of an easy handling automatised interface all the kinds of already existing corneal transplants. Also, in order to maximize the spatial quality of the beam, a wavefront correction system using a deformable mirror module has been added. The Demonstrator contains an erbium fiber laser emitting at 1,6 microns. This laser delivers a beam of a few Joule with pulse duration of 700 femtoseconds and a repetition rate of 100‐200 KHz. It includes deformable mirrors permitting horizontal displacements and a wavefront sensor. It also contains the administration system of the laser beam. Results The experiments carried out with a surgical tunable source confirmed the initial assumptions: the penetration depth is limited to wavelengths close to 1 microns. When increasing the wavelength, the drop of the scattering compensates the absorption and therefore the penetration depth is slowly varying when increasing the wavelength. The laser does not penetrate near the maximum of the water absorption band located at 1,45 microns. However, the use of a wavelength of 1,6 micros enables an important increasing of penetration depth (factor 3) while conserving the same energy of current technologies. Conclusion The use of a laser source with a wavelength corresponding to the window of transparency of the cornea (1,65 microns) permits to increase both the penetration depth of an ultrafast laser source and the cut quality. [ABSTRACT FROM AUTHOR]