First clinical results of epithelial laser in situ keratomileusis with a 1000 Hz excimer laser

Mohrenfels, C. Winkler von; Khoramnia, Ramin; Wüllner, Christian; Donitzky, Christof; Salgado, Josefina; Pfäffl, Wolfgang; Lohmann, Chris-Patrick

doi:10.1016/j.jcrs.2009.10.041

Cited by 9 publications

(6 citation statements)

References 25 publications

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“…The quality of ablations performed with a repetition rate of 200, 500 and 1000 Hz was comparable. We also used the Concept System 1000 in a pilot study for Epi‐LASIK on 30 eyes (Winkler von Mohrenfels et al. 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Our study did not reveal opacities in the interface after performing LASIK with the 1000‐Hz excimer laser. When we used the 1000‐Hz excimer laser for Epi‐LASIK (Winkler von Mohrenfels et al. 2010), 83% of the eyes had a clear cornea 3 months after surgery, and only 17% of the eyes showed a haze of 0.5 on a scale between 0 and 4 described by Fantes et al.…”

Section: Discussionmentioning

confidence: 99%

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

Khoramnia

Salgado

Wuellner³

et al. 2011

Acta Ophthalmologica

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. 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.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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

Khoramnia

Salgado

Wuellner³

et al. 2011

Acta Ophthalmologica

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“…The thermal load problem in refractive surgery in relation to the frequency controls has been explored by many researchers and commercial platforms in the past. 11,[36][37][38] Our results suggest that increasing Fig. 9 A comparison of the achieved change in peak corneal temperature versus the model predicted values for the corresponding settings.…”

Section: Effect Of Epitheliummentioning

confidence: 87%

Analysis of the change in peak corneal temperature during excimer laser ablation in porcine eyes

Arba-Mosquera

Verma

2015

J. Biomed. Opt.

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The objective is to characterize the impact of different ablation parameters on the thermal load during corneal refractive surgery by means of excimer laser ablation on porcine eyes. One hundred eleven ablations were performed in 105 porcine eyes. Each ablation was recorded using infrared thermography and analyzed mainly based on the two tested local frequencies (40 Hz, clinical local frequency; 1000 Hz, no local frequency). The change in peak corneal temperature was analyzed with respect to varying ablation parameters [local frequency, system repetition rate, pulse energy, optical zone (OZ) size, and refractive correction]. Transepithelial ablations were also compared to intrastromal ablations. The average of the baseline temperature across all eyes was 20.5°C±1.1 (17.7°C to 22.2°C). Average of the change in peak corneal temperature for all clinical local frequency ablations was 5.8°C±0.8 (p=3.3E-53 to baseline), whereas the average was 9.0°C±1.5 for all no local frequency ablations (p=1.8E-35 to baseline, 1.6E-16 to clinical local frequency ablations). A logarithmic relationship was observed between the changes in peak corneal temperature with increasing local frequency. For clinical local frequency, change in peak corneal temperature was comparatively flat (r 2 =0.68 with a range of 1.5°C) with increasing system repetition rate and increased linearly with increasing OZ size (r 2 =0.95 with a range of 2.4°C). Local frequency controls help maintain safe corneal temperature increase during excimer laser ablations. Transepithelial ablations induce higher thermal load compared to intrastromal ablations, indicating a need for stronger thermal controls in transepithelial refractive procedures.

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“…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.…”

Section: Diskussionunclassified

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

Tandogan

Khoramnia

Gye

et al. 2016

Klin Monatsbl Augenheilkd

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The objective of this study was to evaluate postoperative clinical outcomes of photorefractive keratectomy (PRK) using different ablation frequencies. In this prospective, contralateral eye study, 56 eyes of 28 patients with myopia or myopic astigmatism were included. PRK was performed using the MEL90 excimer laser system (Carl Zeiss Meditec, Germany). One eye of each patient was treated with a repetition rate of 250 Hz, while the other one was treated with a repetition rate of 500 Hz. The treatment pattern in the 250 Hz and 500 Hz group only differed in terms of ablation frequency; there was no difference in laser pulse energy, spot size or ablation profile. Postoperative follow-ups were at 3 and 7 days and 1, 3 and 6 months. The following parameters were assessed: Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), higher-order aberrations (HOAs), corneal re-epithelisation time and corneal haze. Ablation depth was proportional to laser pulse counts at both frequencies. At 6 months, 100.0% of the eyes in the 250 Hz group and 96.4% in the 500 Hz group had a UDVA of 0.00 logMAR or better; 100% of the eyes in both groups were within ± 1.00D of the attempted correction. All eyes had a postoperative CDVA of 0.00 logMAR or better. There was no difference between the groups in postoperative HOAs, corneal re-epithelisation time or corneal haze. Photorefractive keratectomy with a repetition rate of 250 Hz and 500 Hz showed comparable efficacy, safety and predictability in the correction of myopia. There were no significant complications due to the high repetition rate, such as postsurgical corneal haze.

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First clinical results of epithelial laser in situ keratomileusis with a 1000 Hz excimer laser

Abstract: In this pilot series, the use of the 1000 Hz excimer laser did not lead to the clinical side effects that are potentially associated with the use of a high repetition rate. The safety, stability, and efficacy of the laser were high although no adjustments to the nomogram were made.

Cited by 9 publications

References 25 publications

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

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

Analysis of the change in peak corneal temperature during excimer laser ablation in porcine eyes

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

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