Abstract:With the rapid development over the past two decades,femtosecond(10-15s)lasers(FS)has become a new application in ophthalmic surgery. As laser power is defined as energy delivered per unit time, decreasing the pulse duration to femtosecond level(100fs)not only increases the power delivered but also decreases the fluence threshold for laser induced optical breakdown. In ablating tissue, FS has an edge over nanosecond lasers as there is minimal collateral damage from shock waves and heat conduction during surgical ablation. Thus, application of FS has been widely spread, from flap creation for laser-assisted in situ keratomileusis(LASIK)surgery, cutting of donor and recipient corneas in keratoplasty, creation of pockets for intracorneal ring implantation. FS applied in keratoplasty is mainly used in making graft and recipient bed, and can exactly cut different tissue of keratopathy. FS can also cut partial tissue of cornea, even if it is under the moderate corneal macula and corneal edema condition.
