Why Use Ultrashort Pulses in Ophthalmology and Which Factors Affect Cut Quality

Abstract

The power density of femtosecond lasers and exposure time to the tissue are crucial for a successful procedure in terms of safety and precision. The reduction of the pulse duration allows reducing the quantity of the energy to be delivered to the tissue for disruption with strongly diminished mechanical and thermal collateral damage. The cutting effect of ultra-short pulses is very precise, minimally traumatic, safe, and predictable. Future developments will lead to further energy reductions to achieve optical breakdowns. However, the pulse length cannot be shortened arbitrarily because below 100 fs nonlinear effects can change the process in an unfavorable way. Compared to manual-conventional cataract surgery, femtosecond laser-assisted cataract surgery (FLACS) shows many advantages in clinical application, especially with regard to precision and tissue protection. The femtosecond laser has become particularly important and has made the overall procedure safer when we deal with complex cataract cases such as subluxated lenses. We provide an overview of the evolution of femtosecond laser technology for use in refractive and cataract surgeries. This article describes the advantages of available laser platforms with ultrashort pulses and mainly focuses on the technical and physical backgrounds of ophthalmic surgery technologies.

Comparison of Conventional and Femtosecond Laser-Assisted Cataract Surgery Regarding Macula Behavior and Thickness

“…In general, the FLACS method is described to have specific advantages over PCS, such as faster visual rehabilitation, which is confirmed by our study. It is also considered to be gentler overall, as shown in various other publications [5][6][7][8][9][10][11].…”

“…Over the years, femtosecond laser-assisted cataract surgery (FLACS) has gained more and more attention due to its potential advantages over the conventional phacoemulsification method. These include higher accuracy and reproducibility [5], with potentially better refractive outcomes [6], less endothelial cell loss [7][8][9], shorter effective phacoemulsification time [5,10] and supposedly lower intraoperative complication rates [11]. It is known that with FLACS, the phacoemulsification time can potentially be shortened and the applied energy can be reduced as a result.…”

Update on Femtosecond Laser-Assisted Cataract Surgery: A Review

“…Commonly, high-energy FLACS produces less smooth and notched capsulotomy edges than low-energy pulse FS; 9,96 this microscopic difference may account for the very low incidence of anterior capsule complications in low-energy FLACS, comparable to CP. 10,41,97 Either way, the overall implications of all capsule-related complications (such as the need for vitreoretinal or affecting visual outcomes) seem to be not statistically significant in a global comparison between FLACS and CP. 40,79,98 Nevertheless, the impact of such events should not be underestimated in the context of premium IOL implantation, as it irrevocably compromises surgical success, as capsular integrity and further optimal centration are paramount in the final result.…”

“…Commonly, high-energy FLACS produces less smooth and notched capsulotomy edges than low-energy pulse FS; 9 , 96 this microscopic difference may account for the very low incidence of anterior capsule complications in low-energy FLACS, comparable to CP. 10 , 41 , 97 …”