Evidence map›Paper›PMID 28741162›Full record

ArticleDer Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft2018

[Scanning electron microscopic investigations of cutting edge quality in lamellar keratotomy using the Wavelight femtosecond laser (FS-200) : What influence do spot distance and an additional tunnel have?]

T Hammer, T Höche, J Heichel

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Article in Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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4 · The record

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5 · Who and what money

Authors and funding

3 authors at 3 institutions in 1 country.

T HammerAugenzentrum "Frohe Zukunft", Dessauer Str. 194, 06118, Halle (Saale), Deutschland. augenarzt-hammer@web.de.
T HöcheFraunhofer Institut für Mikrostruktur von Werkstoffen und Systemen, Halle (Saale), Deutschland.
J HeichelKlinik und Poliklinik für Augenheilkunde, Universitätsklinikum Halle (Saale), Halle (Saale), Deutschland.
Fraunhofer Institute for Microstructure of Materials and Systems · DEKlinik und Poliklinik für Augenheilkunde Universitätsklinikum Regensburg · DEUniversity Hospital in Halle · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundFemtosecond lasers (fs-lasers) are established cutting instruments for the creation of LASIK flaps. Previous studies often showed even rougher surfaces after application of fs-laser systems compared to lamellar keratotomy with mechanical microkeratomes. When cutting the cornea with fs-lasers, an intrastromal gas development occurs, which has a potentially negative influence on the cutting quality if the gas cannot be dissipated; therefore, manufacturers have chosen the way of gas assimilation in so-called pockets. The investigated system creates a tunnel which opens under the conjunctiva. The aim of this study was to investigate the effects of a tunnel as well as the influence of different spot distances on the quality of cut surfaces and edges. MATERIAL AND

methodsIn this experimental study on freshly enucleated porcine eyes (n = 15), the following cuts were carried out with the FS-200 (Wavelight, Erlangen, Germany): 1. standard setting (spot and line separation 8 µm), 2. with tunnel for gas drainage, 3. without gas-conducting tunnel, 4. with increased spot spacing (spot and line separation 9 μm instead of 8 μm) and 5. with reduced spot spacing (spot and line separation 7 μm instead of 8 μm). Subsequently, scanning electron microscopy (FEI Quanta 650, Hillsboro, OR) of the cut edges and surfaces as well as the gas drain tunnel were performed. The evaluation was based on an established score.

resultsThe current fs-laser system (200 Hz) is able to create smooth cutting surfaces and sharp edges. The changed density of laser pulses compared to the standard settings with a reduced or increased distance between the pulses, did not achieve any further improvement in the surface quality. The gas-conducting tunnel could be detected by scanning electron microscope. In the case of cutting without a tunnel, roughened surfaces and irregularities on the cutting edges were found.

conclusionWhen the FS-200 fs-laser is used, LASIK cuts with very smooth cut surfaces and sharp cutting edges are achieved. This is only valid as long as an additional tunnel with the fs-laser is placed under the conjunctiva. It can be assumed that the resulting gas is effectively drained through this tunnel. The installation of the tunnel represents a new possibility to replace previous techniques of gas assimilation in deeper lying cutting areas.

Indexed as

ElectronsKeratomileusis, Laser In SituAnimalsCorneaCorneal StromaGermanyMicroscopy, Electron, ScanningSwineFemtosecond laserLASIKMicrokeratomeRefractive surgeryScanning electron microscopy

Identifiers

PMID28741162
OpenAlexW2737494945

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.