Clinical photoablation with a 500-Hz scanning spot excimer laser.

PURPOSE The aim of this study was to use a 500-Hz scanning spot laser (Concept500, WaveLight Laser Technologie AG, Erlangen, Germany) to investigate potential side effects that might be associated with the use of a high repetition rate laser platform. METHODS Seven eyes were treated using a 500-Hz scanning spot laser for laser in situ keratomileusis (LASIK). The local frequency of the ablation was kept below 40 Hz to avoid local heating of corneal tissue. With the exception of the high repetition rate (500 Hz), all other laser parameters such as fluence, algorithm, ablation profile, and spot diameter were identical to a standard WaveLight Allegretto laser system. Patients were examined at 1 month and 1 year after initial treatment. Preoperative and postoperative examination included manifest sphere and cylinder, uncorrected and best spectacle-corrected visual acuity (BSCVA). RESULTS All eyes were treated for myopia or myopic astigmatism. Five eyes received spherocylindrical and two eyes spherical ablation only. No adverse events correlated with the use of a high repetition rate laser system were observed during surgery or at any point during follow-up. All eyes maintained or had improved BSCVA at 12 months after treatment when compared to preoperative values. CONCLUSION The use of an excimer laser with a maximal repetition rate of 500 Hz and a local repetition rate of less than 40 Hz was free of any specific side effect that might be associated with the use of such a high repetition rate.

[1]  Z. Nagy.  Laser in situ keratomileusis combined with topography‐supported customized ablation after repeated penetrating keratoplasty , 2003, Journal of cataract and refractive surgery.

[2]  T. Seiler,et al.  Aberration-sensing and wavefront-guided laser in situ keratomileusis: management of decentered ablation. , 2002, Journal of refractive surgery.

[3]  M. Knorz,et al.  Topographically-guided laser in situ keratomileusis to treat corneal irregularities. , 2000, Ophthalmology.

[4]  J Wollensak,et al.  Side effects in excimer corneal surgery , 2005, Graefe's Archive for Clinical and Experimental Ophthalmology.

[5]  M Vetrugno,et al.  Corneal temperature changes during photorefractive keratectomy using the Laserscan 2000 flying spot laser. , 2001, Journal of refractive surgery.

[6]  P B Morgan,et al.  Thermal Consequences of Photorefractive Keratectomy , 2001, Cornea.

[7]  R. Nuijts,et al.  Wavefront‐guided versus standard laser in situ keratomileusis to correct low to moderate myopia , 2002, Journal of cataract and refractive surgery.

[8]  A Langenbucher,et al.  Experimental correction of irregular corneal astigmatism using topography-based flying-spot-mode excimer laser photoablation. , 1998, American journal of ophthalmology.

[9]  S. Trokel,et al.  Correction of irregular astigmatism with the excimer laser. , 1994, Ophthalmology.

[10]  P B Morgan,et al.  Corneal Temperature Changes During Photorefractive Keratectomy , 1997, Cornea.

[11]  Minoru Obara,et al.  Measurement of the surface temperature of the cornea during ArF excimer laser ablation by thermal radiometry with a 15‐nanosecond time response , 2002, Lasers in surgery and medicine.

[12]  M. Arif,et al.  Spot size and quality of scanning laser correction of higher order wavefront aberrations. , 2001, Journal of refractive surgery.

[13]  M Kaemmerer,et al.  Wavefront-guided laser in situ keratomileusis: early results in three eyes. , 2000, Journal of refractive surgery.

[14]  David R Williams,et al.  Effect of beam size on the expected benefit of customized laser refractive surgery. , 2003, Journal of refractive surgery.