gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

In-vitro comparison of flap and stroma morphology of current microkeratomes for LASIK

Meeting Abstract

  • corresponding author J. Kampmeier - Department of Ophthalmology, University of Ulm
  • S. Schäfer - Department of Ophthalmology, University of Ulm
  • R. Spallek - Department of Ophthalmology, University of Ulm
  • D. Russ - Institut für Lasertechnologien in der Medizin und Messtechnik, University of Ulm
  • T. Pohl - Institut für Lasertechnologien in der Medizin und Messtechnik, University of Ulm
  • G. K. Lang - Department of Ophthalmology, University of Ulm

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogSO.04.04

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dog2004/04dog444.shtml

Published: September 22, 2004

© 2004 Kampmeier et al.
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Outline

Text

Objective

In-vitro examination of morphology of flap thickness and stromal bed after LASIK in swine eyes.

Methods

The microkeratomes Carriazo-Pendular (Schwind), Hansatome (Bausch&Lomb), MK-2000 (Nidek) and Amadeus (AMO) were used for cutting flaps, n = 13 each, on freshly enucleated swine eyes and synthetic eye-models. The flap thickness of swine eyes was determined using a non-contact, confocal optical distance measuring device (CHR 150N, Jurca) and also of eye-models using a mechanical thickness measuring device (Käfler). The morphology of the stromal bed was examined by photography, light-microscopy, scanning electron microscopy and confocal optical distance measurements.

Results

The optical/mechanical flap thickness measurements showed an average difference compared to the adjusted thickness of +11±14 / +0±0 μm (Carriazo-Pendular), -3±27 / +90±0 μm (Hansatome), -4±7 / +80±0 μm (MK-2000) and -35±5 / +40±0 μm (Amadeus). Histology showed no mechanical damage and smooth, slightly undulating surfaces in all microkeratomes. In scanning electron microscopic examination, the stromal surface was found to be more homogeneous and smoother in the case of the microkeratome Amadeus, followed by Hansatome, MK-2000 and Carriazo-Pendular. Average roughness of the ablation surface was 0.29±0.06 μm (Carriazo-Pendular), 0.27±0.05 μm (Hansatome), 0.23±0.04 μm (MK-2000) and 0.22±0.06 μm (Amadeus).

Conclusions

The stromal bed showed in all cases only a slight roughness, which seems to be acceptable for the clinical outcome. However, the more critical point are larger amounts of differences in flap thickness compared to the adjusted thickness. There were also remarkable differences between mechanical and optical measurements of flap thickness.