Safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser

Abstract

. Purpose: To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany). Methods: LASIK was performed on twenty eyes with myopia or myopic astigmatism (mean spherical equivalent refraction: −3.97 ± 1.72 dioptres (D); mean cylinder: −0.84 ± 0.77 D) using a microkeratome for flap creation and the Concept System 1000 for photoablation. Patients were examined preoperatively as well as 1, 3 and 6 months after the treatment. Manifest sphere and cylinder, uncorrected (UCDVA) and best corrected (BCDVA) distance visual acuity, corneal topography and pachymetry were analysed. Results: We observed no adverse events that might have been associated with the use of a repetition rate of 1000 Hz. All eyes maintained or had improved BCDVA at 6 months after treatment when compared to preoperative values. Six months after LASIK, UCDVA was 20/20 or better in 85% and 20/25 or better in 100% of the eyes. The spherical equivalent refraction was within ±0.50 D in 95% of the eyes at 6 months after surgery. The refraction stayed stable over time; 95% of the eyes changed <0.5 D postoperatively. Conclusion: LASIK with the prototype 1000‐Hz excimer laser was safe, efficient and predictable. The postoperative refraction was stable over time. There were no specific clinical side‐effects that might be associated with the use of such a high repetition rate.

Results of laser in situ keratomileusis performed using solid-state laser technology

“…12 In our study, the overall mean efficacy index was 0.99 and safety index, 1.02. These values are comparable to those obtained after myopic LASIK with the last generation of excimer lasers [16][17][18][19][20] (Table 2). Comparisons of the data in Table 2 should be performed with caution because the data represent different samples of eyes operated on by different physicians using different technologies.…”

“…Similarly, in the study by Tsiklis et al 10 of myopic eyes that had LASIK with the same technology, 90% of eyes had an SE within G0.50 D ( Table 2). This level of refractive correction predictability is equivalent to, and in some cases better than, that reported with the last generation of excimer lasers (SE within G0.50 D in 90% of eyes or more) 10,[16][17][18][19][20] (Table 2). This excellent refractive predictability was confirmed with the defocus equivalent analysis, which was significantly reduced postoperatively (0.50 D or less in 93.3% of eyes).…”

Influence of the Difference Between Corneal and Refractive Astigmatism on LASIK Outcomes Using Solid-State Technology

“…[24][25][26][27][28] Regarding astigmatism, although the magnitude of refractive cylinder was reduced significantly, the power vector components did not change significantly. These results were consistent with those reported previously after LASIK by our research group 2 (95% of eyes with UDVA of 20/25 or better).…”

Einfluss unterschiedlicher Ablationsfrequenzen auf die klinischen Ergebnisse bei photorefraktiver Keratektomie unter Verwendung derselben Excimer-Laser-Plattform: Ein kontralateraler Vergleich

“…Im Zuge der Weiterentwicklung der Lasertechnologie sind über das letzte Jahrzehnt neue Laserplattformen, die sich hinsichtlich der Frequenz, des Musters und der Energie der Ablation sowie der Pulsgröße unterscheiden, eingeführt worden. Einige Studien zu Excimer-Laser-Systemen mit hohen Repetitionsraten (750 oder 1050 Hz) haben bei diesen Lasersystemen bereits über ein hohes Maß an Sicherheit, Wirksamkeit sowie Vorhersagbarkeit berichten können [8,[11][12][13][14][15]. Bei Lasersystemen mit erhöhten Repetitionsraten konnten die Spotgröße reduziert und die Pulsenergie mit dem Ziel angepasst werden, dass das Ausmaß von Komplikationen (z.…”

“…Ins-besondere thermische Schäden am Hornhautstroma stellen eine mögliche Nebenwirkung höherer Abtragungsfrequenzen dar. Durch die Applikation multipler Laserspots in einem bestimmten Areal kann es durch kumulativen Energieeintrag zu einer Erhöhung der Temperatur kommen [11,21]. Derartige thermische Schäden können sich in Form einer erhöhten postoperativen Entzündungsreaktion undim Falle der Laser-in-situ-Keratomileusis (LASIK)auch in Form einer Trübung im Interface in der frühen postoperativen Phase manifestieren.…”