Comparison between femtosecond laser assisted and mechanical surgical techniques in corneal refractive surgeries

Abstract

The invention of the FS laser technology has allowed great advances in the field of corneal surgery. The FS laser uses ultra-short pulse duration to create photodisruption, a process that allows corneal tissue to be cut at precise depths and in various patterns with minimal collateral tissue damage for which five types of the femtosecond laser systems are available in the refractive surgery market. At present corneal flap creation in LASIK surgery is the most common application of the FS laser. The major advantages of FS laser flap creation over the mechanical MK are reduced incidence of flap complications, greater surgeon choice of flap diameter, size and capability of cutting uniform and thin flaps. FS LASIK complications are rare, but include unique problems, such as opaque bubble layer (OBL) and the transient light-sensitivity syndrome (TLSS). Rainbow glare is another side effect unique to the FS laser, but a decrease in the incidence of LASIK-induced dry eye has been reported. Further advances in FS technology are allowing a variety of full thickness corneal cuts to be made. FS laser can be programmed to create tunnels for ICRS implantation and can be utilized in arcuate keratotomy and/or wedge resection for the correction of high astigmatism following PKP or cataract surgery. Tunnel creation and astigmatic correction with FS laser is easier than with the traditional methods, more precise and more predictable, and less likely to perforate cornea. The so called FS Lenticule Extraction (FLEx); is a single laser refractive procedure which allows for complete refractive correction without an excimer laser and it has several advantages like shortened length of the refractive procedure. Another modification for FLEx is small incision lenticule extraction (SMILE), despite more challenging technique, better refractive results were reported.