الفهرس | Only 14 pages are availabe for public view |
Abstract Femtosecond laser technology was first introduced practically into refractive surgery in 2001 as advancement from ps and ns lasers. The FS laser is an infrared laser that gives ultra short pulses with a spot size of about 1 µm. This enables the laser to apply less energy to the corneal tissue with the advantage of a more precise surgical effect. Femtosecond laser uses a wavelength of 1053 nm that can pass through the outer layers of the cornea with no effect on the tissue until it reaches the pre–programmed target. Upon reaching this target, the beam forms microscopic bubbles of carbon dioxide and water vapor in a process called photodisruption. Thousands of these bubbles are placed at a precisely controlled depth to define a resection plane. Using the rapidly fired FS laser and interconnecting the bubbles very tightly creates a corneal resection plane with remarkable precision and accuracy. The current generations of FS laser system are IntraLase, Femtec, Femto LDV and VisuMax. These generations generate FS laser pulses at a repetition rate ranging from 10 to 200 KHz. |