الفهرس | Only 14 pages are availabe for public view |
Abstract The femtosecond laser is a focusable infrared laser, which utilizes pulses in the femtosecond (10-15 s) duration range. Contiguous pulses are placed at a precise depth within the cornea. The 1053 nm wavelength of light used by the laser is transparent to the cornea, thus resecting only targeted tissue, while leaving surrounding tissue unaltered. With the energy and firing pattern controlled by computer, the laser is capable of cutting tissue at various depths and patterns, producing minimal inflammation or collateral tissue damage. The FS laser permits photodisruption of the cornea at low energy levels and with high precision, making it a very useful tool for corneal surgery. The flexibility of the laser platform permits the customization of LASIK flaps, as well as the production of unique trephination patterns in penetrating and lamellar keratoplasties, can be programmed to create channels for the implantation of intracorneal ring segments and intrastromal correction of presbyopia. While offering an excellent safety profile, the FS laser also produces LASIK outcomes that are equivalent, or slightly superior to those of blade-based microkeratomes. Surgical procedures such as pattern keratoplasty are technically challenging but femtosecond laser-assisted surgery can allow precise creation of corneal resection planes, even in situations with limited optical clarity due to edema or scar tissue. Although the FS laser has an excellent safety profile, it still carries the risk of complications, such as decentration, diffuse lamellar keratitis, flap stria, and transient light sensitivity. Although the cost of the femtosecond laser is considerable, improving patient outcomes and surgical efficiency will improve surgeon and patient access to this evolving technology. Femtosecond lasers represent an exciting new technology in refractive surgery. Clear advantages and disadvantages have emerged after several years of widespread usage, and it is likely that further experience and refinement will make femotsecond lasers the predominant method in refractive surgery. |