In FLACS, some major steps of cataract surgery is performed automatically by the laser system. This includes the creation of access incisions in the cornea, the formation of a window or opening in the bag/capsule that envelopes the cataractous lens, mitigation of existing astigmatism of the eye through the creation of arcuate or limbal relaxing incisions, and then, the division and “softening” of the central hard portion of the cataractous lens (nucleus) in preparation for its total removal via phaco-emulsification and aspiration. Once the cataract is totally cleared from the bag, a foldable intraocular lens is then inserted and deployed.
FLACS uses a laser which fires at an ultra rapid rate, creating ultrashort pulses of a femto-second in duration. A femto-second is the SI unit of time equal to 10−15 or 1/1,000,000,000,000,000 of a second; that is, one quadrillionth, or one millionth of one billionth, of a second.4A laser fired with such short intervals allowfor the creation of tissue planes within the eye, with very little heat, and thuscollateral damage to surrounding tissues is eliminated. To date, five femto-second laser technology platforms are commercially available for cataract surgery:Catalys (Optimedica), Lensx (Alcon Laboratories, Inc.),Lensar (Lensar, Inc.), Victus (Technolas) and Femto LDV Z8 (Ziemer Ophthalmic Systems, AG).
The advent of FLACS has helped to improve cataract surgery but not without some shortfalls. Several clinical studies have indicated that femtosecond laser capsulotomies are significantly more precise in size and reproducibility than those created manually by the surgeon, resulting ina more stable refractive result with less IOL tilt anddecentration than a manual CCC, an important factor, especially with the use of toric(specialized lenses for the correction of astigmatism) and premium multi-focal intraocular lenses.5-11However, femto capsulotomies may sometimes be complicated by the production of incomplete capsular tags, which may tear, and compromise the strength of the capsulotomies in comparison to manual capsulotomies which do not have them.12Nevertheless, with improvement in software and systems, femtosecond capsulotomies are now more consistent and “free-floating”.