Surgery of the anterior segment of the eye assisted by ultrashort pulse laser: optimisation of the parameters with respect to tissular transparency and cell viability Syed Asad Hussain To cite this version: Syed Asad Hussain. Surgery of the anterior segment of the eye assisted by ultrashort pulse laser: op- timisation of the parameters with respect to tissular transparency and cell viability. Physics [physics]. École Polytechnique, 2014. English. tel-01097301 HAL Id: tel-01097301 https://hal.archives-ouvertes.fr/tel-01097301 Submitted on 6 Jan 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives| 4.0 International License Thèse Présentée pour l’obtention du titre de Docteur es Science de l’École Polytechnique Spécialité : Physique Par Syed Asad Hussain Surgery of the anterior segment of the eye assisted by ultrashort pulse laser: optimisation of the parameters with respect to tissular transparency and cell viability. Soutenue le : 19 Septembre 2014 Jury composé de : THURET Gilles Rapporteur TUALLE Jean-Michel Rapporteur DRUON Frédéric GEORGES Gaëlle SCHANNE-KLEIN Marie-Claire PLAMANN Karsten Directeur de thèse Préparée au Laboratoire d’Optique Appliquée ENSTA ParisTech – École Polytechnique – CNRS UMR 7639 Palaiseau, France http://loa.ensta.fr/ UMR 7639 - 2 - Abstract The goal of this work was to study different microscopic and macroscopic effects that will ultimately help us to improve procedures in eye surgery assisted by ultrashort pulse lasers and most notably keratoplasty (corneal grafting), which requires laser systems which are op- erational in pathological and therefore strongly light scattering tissue. Previously, the Optique Photonique Santé (OPS) group at the Laboratoire d'Optique Appliquée (LOA) had identified 1650 nm as an optimum wavelength at which light scattering processes inside the pathological cornea are minimised. During the present thesis, three main tasks have been addressed. An ultrashort pulse laser system based on non-linear optical crystals has been devel- oped, optimised with respect to the requirements of laser eye surgery, and fully char- acterised. The finished set-up is compact, robust, simple and potentially qualified for clinical use. In collaboration with a group at IESL-FORTH (Iraklion, Greece) and with the partici- pation of a previous PhD student of the group we have studied the interaction of ul- trashort pulses with water, collagen (type I) solution and porcine cornea. Data on la- ser-tissue-interaction is precious because the interaction dynamics is usually only documented for water; our results will help to develop a tissue-specific model for the interaction process. We have investigated the interaction of the laser pulses and the effects it causes with live cells in the corneal endothelium. The preservation of endothelial cell viability is crucial notably for specific keratoplasty routines which require incisions close to the endothelium; compromised endothelial cell viability – which is likely caused by the effects of shock waves generated by optical breakdown and bubble formation – may lead to a failure of the surgical intervention. “Safe” sets of parameters concerning pulse energy and incision geometry need to be defined. We explored the maximum permitted pulse energy values at any given distance to the endothelial cells and mini- mal distances for given pulse energies and estimated the associated shock wave ampli- tudes. - 3 - Résumé Le but de ce travail a été d'étudier les différents effets microscopiques et macrosco- piques susceptibles de nous aider à améliorer les procédures de chirurgie oculaire assistée par les lasers à impulsions ultra-courtes ; plus particulièrement en kératoplastie (greffe de cornée), qui nécessite des systèmes lasers opérationnels dans les tissus pathologiques et donc de diffu- sant fortement la lumière. Antérieurement, le groupe Optique Photonique Santé (OPS) du Laboratoire d'Optique Appliquée (LOA) a identifié 1650 nm comme étant une longueur d'onde optimale à laquelle les processus de diffusion de la lumière à l'intérieur de la cornée pathologique sont minimisés. Au cours de cette thèse, trois tâches principales ont été abordées. Un système laser à impulsions ultra-courtes à base de cristaux optiques non linéaires a été mis au point, optimisée par rapport aux exigences de chirurgie oculaire au laser, et entièrement caractérisé. Le montage achevé est compact, robuste, simple et potentiel- lement apte à un usage en clinique. En collaboration avec un groupe de l’IESL- FORTH (Iraklion, Grèce) et avec la parti- cipation d'un ancien doctorant du groupe, nous avons étudié l'interaction des impul- sions ultra-brèves avec de l'eau, une solution de collagène (type I) et des cornées de porcs. Les données sur les interactions laser-tissu sont précieuses car la dynamique d'interaction est habituellement uniquement documentée pour l'eau; nos résultats aide- ront à élaborer un modèle spécifique de tissu pour le processus d'interaction. Nous avons étudié l'interaction entre les impulsions laser et les effets causés sur des cellules vivantes de l'endothélium cornéen. La préservation de la viabilité des cellules endothéliales est cruciale, notamment pour les routines de kératoplastie spécifiques exigeant des incisions à proximité de l'endothélium ; la viabilité des cellules endothé- liales compromise – probablement causée par les effets des ondes de choc générées par claquage optique et la formation de bulles – peut conduire à un échec de l'interven- tion chirurgicale. Des jeux de paramètres « saufs » concernant l'énergie d'impulsion et de la géométrie de l'incision doivent être définis. Nous avons ainsi exploré les valeurs maximales autorisées de l'énergie de l'impulsion à une quelconque distance donnée des cellules endothéliales et les distances minimales pour les énergies d'impulsions données, et estimé les amplitudes des ondes de choc associées. - 4 - Acknowledgements I would first like to thank Allah for everything that he has given to me. I would like to thank Karsten Plamann for giving me an opportunity to complete my PhD under his supervision. His constant guidance, support and encouragement made this dissertation possible. Thank you also to Antoine Rousse, Carole Gratpanche, Sandrine Tricaud, Patricia Toullier, Octavie Verdun, and Lucie Huguet for their help and providing a great research environment. I am thankful to Gilles Thuret, Jean-Michel Tualle, Druon Frédéric, Georges Gaëlle, Schanne- Klein Marie-Claire (jury members) for their valuable time and suggestions. Then I would like to thank Caroline Crotti and Laura Kowalczuk for technical guidance and assistance during my PhD especially in my early months. Thank you also to Tal Marciano for his scientific discussion and the great time that we spend together. A big thank you to Fatima Alahyane and Zacaria Essaïdi for their help and suggestions. I admire your ability to come up with quick solutions for the various technical as well as administrative problems. In addition, I would like to thank Stelios Tzortzakis, Dimitris G. Papazoglou and Michalis Loulakis for their help on our experiment on Dynamics of fs pulse interaction with corneal tissue and a collagen (type I) solution. Without their razor sharp knowledge of the field the experiment may not be possible. Thanks also to Marc Hanna for his advice and help for our parametric amplification and generation setup. Thanks to Florent Deloison and Hélène Desrus for their time and interest during my whole stay at ALPhANOV. I also would like to thank Arnaud Dubois, Philippe Gain, Zhiguo He, Valeria Nuzzo, Donald Peyrot, Michèle Savoldelli, Iman Aloulou, Isabelle Tang, Mikael Guedj, Maxence Le Sourd, Charles Chalbot, Smail Khelifati, Jean-Pascal Caumes, Denis Tregoat, Florent Guichard, and Antoine Federici who have helped me on various occasions on various aspects during the past three years. I have to specially thank Mickaël Martinez and Jean-Lou Charles for helping me on various technical problems involving mechanics in my experiments. I would like to thank the École Polytechnique graduate school for providing me funding for my PhD, LaserLab for funding our experiment at UNIS Heraklion, Greece. The seventh framework programme of the European Union for funding the acquisition of an infrared cam- era through their NEXPRESSO program. At the end, I like to thank my family and friends for their support, prayers and encouragement in all my endeavours. - 5 - Table of contents INTRODUCTION .....................................................................................................................................................16 SCIENTIFIC OBJECTIVES .............................................................................................................................................17 THESIS PLAN ..........................................................................................................................................................18 CHAPTER I ..............................................................................................................................................................20