Evaluation of the smoothness and accuracy of scanning photorefractive keratectomy on PMMA by optical profilometry

Fabrice Manns, Pascal O. Rol, Jean Marie Parel, Armin Schmid, Jin Hui Shen, Takaaki Matsui, Per G.M.D. Soderberg

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The smoothness and accuracy of PMMA ablations with a prototype scanning photorefractive keratectomy (SPRK) system were evaluated by optical profilometry. A prototype frequency- quintupled Nd:YAG laser (Laser Harmonic, LaserSight, Orlando, FL) was used (wavelength: 213 nm, pulse duration: 15 ns, repetition rate: 10 Hz). The laser energy was delivered through two computer-controlled galvanometer scanners that were controlled with our own hardware and software. The system was programmed to create on a block of PMMA the ablations corresponding to the correction of 6 diopters of myopia with 60%, 70%, and 80% spot overlap. The energy was 1.25 mJ. After ablation, the topography of the samples was measured with an optical profilometer (UBM Messtechnik, Ettlingen, Germany). The ablation depth was 10 to 15 micrometer larger than expected. The surfaces created with 50% to 70% overlap exhibited large saw-tooth like variations, with a maximum peak to peak variation of approximately 20 micrometer. With 80% overlap, the rms roughness was 1.3 micrometer and the central flattening was 7 diopters. This study shows that scanning PRK can produce smooth and accurate ablations.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsJean-Marie Parel, Karen M. Joos, Pascal O. Rol
Pages57-60
Number of pages4
StatePublished - Jan 1 1996
EventOphthalmic Technologies VI - San Jose, CA, USA
Duration: Jan 27 1996Jan 28 1996

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume2673

Other

OtherOphthalmic Technologies VI
CitySan Jose, CA, USA
Period1/27/961/28/96

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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  • Cite this

    Manns, F., Rol, P. O., Parel, J. M., Schmid, A., Shen, J. H., Matsui, T., & Soderberg, P. G. M. D. (1996). Evaluation of the smoothness and accuracy of scanning photorefractive keratectomy on PMMA by optical profilometry. In J-M. Parel, K. M. Joos, & P. O. Rol (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (pp. 57-60). (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 2673).