Editor-in-Chief: BENJAMIN F. BOYD, M.D., F.A.C.S. Editors: SUNITA AGARWAL, M.S.;D.O.;F.S.V.H. ATHIYA AGARWAL, M.D.;D.O.;F.R.S.H. AMAR AGARWAL, M.S.;F.R.C.S.;F.R.C.Ophth i Project Director: Andres Caballero, Ph.D Production Manager: Kayra Mejia Page Design and Typesetting: Kayra Mejia Laura Duran Art Design: Eduardo Chandeck Spanish Translation: Prof. Juan Murube, M.D. Sales Manager: Tomas Martinez Marketing Manager: Eric Pinzon Customer Service Manager: Miroslava Bonilla International Communications: Joyce Ortega ©Copyright, English Edition, 2002 by HIGHLIGHTS OF OPHTHALMOLOGY All rights reserved and protected by Copyright. No part of this publication may be reproduced, stored in retrieval system or transmitted in any form by any means, photocopying, mechanical, recording or otherwise, nor the illustrations copied, modified or utilized for projection without the prior, written permission of the copyright owner. Due to the fact that this book will reach ophthalmologists from different countries with different training, cultures and backgrounds, the procedures and practices described in this book should be implemented in a manner consistent with the professional standards set for the circumstances that apply in each specific situation. Every effort has been made to confirm the accuracy of the information presented and to correctly relate generally accepted practices. The authors, editors, and publisher cannot accept responsibility for errors or exclusions or for the outcome of the application of the material presented herein. There is no expressed or implied warranty for this book or information imparted by it. Any review or mention of specific companies or products is not intended as an endorsement by the authors or the publisher. Boyd, Benjamin F., M.D.; Agarwal, Sunita, M.S.; Agarwal, Athiya, M.D.; Agarwal, Amar, M.D. "LASIK and Beyond LASIK - Wavefront Analysis and Customized Ablation" ISBN Nº 9962-613-04-3 Published by:Highlights of Ophthalmology Int'l P.O. Box 6-3299, El Dorado City of Knowledge Clayton, Bldg. 207 Panama, Rep. of Panama Tel: (507)-317-0160 FAX: (507)-317-0155 E-mail: [email protected] Worldwide Web:www.thehighlights.com Printed in Bogota, Colombia. You may contact HIGHLIGHTS OF OPHTHALMOLOGY INC., for additional information about other books in this field or about the availability of our books. ii EDITOR-IN-CHIEF BENJAMIN F. BOYD, M.D., D.Sc. (Hon), F.A.C.S. Doctor Honoris Causa Immediate Past President, Academia Ophthalmologica Internationalis Honorary Life Member, International Council of Ophthalmology Editor-in-Chief and Author, HIGHLIGHTS OF OPHTHALMOLOGY, 25 Hard Cover Volumes and the 15 million copies of HIGHLIGHTS OF OPHTHALMOLOGY Bi-Monthly Journal. Recipient of the Duke-Elder International Gold Medal Award (International Council of Ophthal- mology), the Barraquer Gold Medal (Barcelona), the First Benjamin F. Boyd Humanitarian Award and Gold Medal for the Americas (Pan American), the Leslie Dana Gold Medal and the National Society for Prevention of Blindness Gold Medal (United States), Moacyr Alvaro Gold Medal (Brazil), the Jorge Malbran Gold Medal (Argentina), the Favaloro Gold Medal (Italy). Recipient of The Great Cross Vasco Nuñez de Balboa Panama's Highest National Award. EDITORS DR. SUNITA AGARWAL, M.S.;D.O.;F.S.V.H. (Germany) Pioneer in the world in the field of Laser Cataract Surgery. She heads Dr.Agarwal’s Eye Hospital at Bangalore, India and Dr.Agarwal’s Eye Clinic at Dubai (UAE). She is an expert in the field of Lasik Laser as she is in the field of cataract surgery under No Anesthesia. She has brought out for the first time in the world the use of the Air Pump as a new method to prevent surge and also found out that the internal tube of the phaco machine can lead to endophthalmitis . She practices at Dr.Agarwal’s Eye Hospital, 15 Eagle Street, Langford town, Bangalore-560 025, India and at Dr.Agarwal’s Eye Clinic,Villa No.2, Roundhouse 3, Al Wasl Road, Dubai Post box 9168, UAE. DR. ATHIYA AGARWAL, D.O.;F.R.S.H. (London) Excellent surgeon who trains ophthalmologists from all over the world in Lasik and Phaco. She performs No anesthesia cataract surgery, Phakonit and Lasik Laser quite easily. Dr.Athiya is a very good speaker and teaches routinely in various conferences nationally and internationally. She practices at Dr.Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai (Madras) – 600 086, India. DR. AMAR AGARWAL, M.S.;F.R.C.S.;F.R.C.Ophth (London) Started for the first time in the world "No anesthesia cataract surgery", "Phakonit (cataract removal through a 0.9 mm incision)" and "Favit" a new technique to remove dropped nuclei. He is a very dynamic speaker. He has a double FRCS to his credit. His parents Dr. J. Agarwal and Dr. Mrs.T.Agarwal, Sister Dr.Sunita Agarwal, wife Dr.Athiya Agarwal and Brother-in-law Mr.Pankaj Sondhi help him in his aim to perfection. He practices at Dr.Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai (Madras) – 600 086, India. Dr.Agarwal’s Eye hospital at Chennai is the only eye hospital in the world built in the shape of an eye and has been included in the Ripley’s Believe it or not series. Dr.Agarwal’s Eye Hospital is at Chennai (India), Bangalore (India) and Dubai. The web site of the hospital is: http://www.dragarwal.com iii Contributing Authors Agarwal, Amar, M.S.,FRCS;FRCOphth Avalos U., Guillermo, M.D. Carvalho, Luis A., PhD. Medical Director, Chief, Department of Ophthalmology Institute of Physics Dr. Agarwal's Group of Eye Hospital Hospital Sagrado Corazon; University of Sao Paulo, Brazil Chennai, India Medical Director, Clinica Laser Oftalmico Castro, Jarbas C., PhD. Agarwal, J., FORCE;DO;FICS Guadalajara, Mexico Professor, Chairman, Institute of Physics Dr. Agarwal's Group of Eye Hospital, Belda, Jose I., M.D. University of Sao Paulo, Brazil Chennai, India; Instituto Oftalmologico de Alicante Bangalore, India; Alicante, Spain Cigales, Melania, M.D. Dubai (UAE) Instituto Oftalmologico de Sabadell Benelli, Umberto, M.D. Sabadell, Spain Agarwal, Sunita, MS;DO;FSVH Department of Neurosciences Medical Director; Section of Ophthalmology Coelho, Etelvino, M.D. Dr. Agarwal's Group of Eye Hospital University of Pisa Director, Centro de Microcirugia Bangalore, India Pisa, Italy Refrativa & Excimer Laser de Minas Gerais Agarwal, T.; FORCE;DO;FICS Border, Andrea D., O.D. Belo Horizonte, MG Brazil Managing Director, Discover Vision Centers Dr. Agarwal's Group of Eye Hospital, Kansas City, Missouri Coret, Andreu, M.D. Chennai, India; Medical Director, Bangalore, India; Instituto Oftalmologico de Barcelona Dubai (UAE) Boyd, Benjamin F., M.D., F.A.C.S. Barcelona, Spain Editor-in-Chief, Alio, Jorge L., M.D. Highlights of Ophthalmology Int., Cummings, Arthur, MB, ChB Mmed Director, Panama, Rep. of Panama (Ophth) FCS(SA), FRCS (Edin) Instituto Oftalmologico de Alicante Wellington Ophthalmic Laser Clinic Alicante, Spain Butler, Jason, M.D. Dublin, Ireland Long Beach Laser Center Attia, Walid, M.D. Long Beach, California Charles, Steve, M.D. Instituto Oftalmologico de Alicante Clinical Professor Alicante, Spain Carriazo E., Cesar, M.D. Department of Ophthalmology Medical and Scientific Director University of Tennessee Carriazo Ophthalmological Center, Center of Health Science Colombia Memphis, Tennessee iv CONTRIBUTING AUTHORS Chamon, Wallace, PhD. Hardten, David R., M.D. Lindstrom, Richard, M.D. Refractive Surgery Division Director of Refractive Surgery Medical Director, Escola Paulista de Medicina Minnesota Eye Consultants; Phillips Eye Center for Teaching University of Sao Paulo, Brazil Clinical Associate Professor of and Research; Ophthalmology Clinical Professor, Choudhry, Saurabh, D.O., FERC. University of Minnesota University of Minnesota, Fellow, Dr. Agarwal's Eye Hospital, Minneapolis, Minnesota Minnesota, Minneapolis Chennai, India Haw, Weldon, M.D. Mahmoud M. Ismail, M.D., Ph.D. Choudhry, Reena, M., DO.;FERC. Cornea & Refractive Surgery, University of Al-Azhar, Fellow, Dr. Agarwal's Eye Hospital, Department of Ophthalmology, Cairo, Egypt Chennai, India Stanford University School of Medicine Stanford, California Manche, Edward E., M.D. Davis, Elizabeth, A., M.D. Assistant Professor of Ophthalmology Associate, Hoyos, Jairo E., M.D. Stanford University Minnesota Eye Consultants, PA; Medical Director School of Medicine Assistant Clinical Professor Instituto Oftalmologico de Sabadell Stanford, California University of Minnesota Sabadell, Spain Minneapolis, Minnesota Martiz, Jaime R., M.D. Hoyos-Chacon, Jairo, M.D. Refractive Surgery Consultant; Denning, James A., B.A., B.S. Instituto Oftalmologico de Sabadell The Laser Center, Houston, Texas; Discover Vision Centers Sabadell, Spain Course Director & President Kansas City, Missouri International Lasik Course Katsanevaki, VJ, M.D. Houston, Texas Doane, John F., M.D. Department of Ophthalmology Discover Vision Centers University of Crete-Medical School McDonald, Marguerite, M.D. Kansas City, Missouri Crete, Greece Director, Southern Vision Institute EuDaly, Lon S., O.D. Knorz, Michael C., M.D. New Orleans, Louisiana Discover Vision Centers Klinikum Mannheim Kansas City, Missouri Mannheim, Germany Morris, Scot, O.D. Discover Vision Centers Feinerman, Gregg, M.D. Koch, Paul S., M.D. Kansas City, Missouri Medical Director, Koch Eye Associates Feinerman Vision Institute, Warwick, Rhode Island Murube, Juan, M.D. Long Beach Laser Center, Professor of Ophthalmology, Long Beach, California; Krueger, Ronald, M.D. University of Alcala; Assistant Clinical Professor, Medical Director, Chairman, Dept. of Ophthalmology, University of California, Department of Refractive Surgery, Hospital Ramon y Cajal Irvine, California The Cleveland Clinic Foundation Madrid, Spain Cole Eye Institute Gatell, Jordi, M.D. Cleveland, Ohio Narang, Sameer, M.S. Instituto Oftalmologico de Barcelona Director, Narang Eye Clinic Barcelona, Spain Lara, Elvira, O.D. Ahmedabad, Gujarat, India Instituto Oftalmologico de Barcelona Ginis, HS., BSc Barcelona, Spain Narang, Priya, M.S. Department of Ophthalmology Director, Narang Eye Clinic University of Crete-Medical School Lavery, Frank, MCh FRCSI FRCS Ahmedabad, Gujarat, India Crete, Greece (Edin) DOMS Wellington Ophthalmic Laser Clinic Narasimhan, Smita, M.B.B.S.,FERC Gomez, Javier J., M.D. Dublin, Ireland Consultant, Dr. Agarwal's Eye Hospital, Instituto Oftalmologico de Alicante Chennai, India Alicante, Spain v CONTRIBUTING AUTHORS Nardi, Marco, M.D. Preetha R., M.B.B.S; FERC Simon-Castellvi, Jose Ma., M.D. Associate Professor Fellow, Dr. Agarwal's Eye Hospital, Clinica Oftalmologica Simon, Department of Neurosciences Chennai, India Barcelona, Spain Section of Ophthalmology University of Pisa Probst, Louis E., M.D. Simon-Castellvi, Sarabel, M.D. Pisa, Italy Medical Director, Clinica Oftalmologica Simon, TLC The Windsor Laser Eye Center, Barcelona, Spain Nguyen, Kim, M.D. Windsor, Ontario, Canada Long Beach Laser Center Slade, Stephen G., M.D. Long Beach, California Sasikanth, RR., MD The Laser Center, Dr. Agarwal's Eye Hospital Houston, Texas Oliveira, Canrobert, M.D. Chennai, India Director, Hospital de Olhos de Brasilia Viera de Carvalho, Luis A., PhD. Brasilia, DF Brazil Schor, Paulo, PhD, M.D. Professor, Bioengineering Division University of Sao Paulo Pallikaris, Ioannis G., M.D. Escola Paulista de Medicina Brazil Department of Ophthalmology University of Sao Paulo University of Crete-Medical School Sao Paulo, Brazil Waring, George, M.D. Crete, Greece Professor of Ophthalmology Emory University; Parul, Goel, M.S., F.E.R.C. Shalaby, Ahmad, M., M.D. Co-Founder Consultant, Dr. Agarwal's Eye Hospital, Instituto Oftalmologico de Alicante Emory Vision Correction Center Chennai, India Alicante, Spain Atlanta, Georgia Perez-Santoja, Juan J., M.D. Simon-Castellvi, Cristina, M.D. Werner, Leonardo P., M.D. Refractive Surgery and Cornea Unit Clinica Oftalmologica Simon, Department of Ophthalmology, Alicante Institute of Ophthalmology Barcelona, Spain São Geraldo Eye Hospital, Miguel Hernandez University Federal University of Minas Gerais School of Medicine Simon-Castellvi, Guillermo L., M.D. and the "Instituto Vizibelli" Alicante, Spain University of Barcelona, Belo Horizonte, Minas Gerais, Brazil Faculty of Medicine, Peters, Tim, M.D. Dept. of Ophthalmology; Wilson, Steven E., M.D. Nationwide Vision Laser & Eye Center, Chief Anterior Segment Surgeon, Chair, Department of Ophthalmology, Clinical Lecturer, Clinica Oftalmologica Simon, and Professor of Vision Research University of Arizona Barcelona, Spain University of Washington Phoenix, Arizona Seattle, Washington vi Contents SECTION I - LASIK FUNDAMENTAL PRINCIPLES OF DIAGNOSIS, CORNEAL MAPPING, MECHANISM OF ACTION OF EXCIMER LASERS CHAPTER 1 CHAPTER 3 UNDERSTANDING REFRACTIVE LASERS EVALUATION OF THE LASIK FLAP BY CONFOCAL MICROSCOPY Therapeutic Principles of Excimer Lasers 1 Advances in Excimer Laser Technology 2 Scanning Lasers 2 Frequent Problems With the Flap 61 Eye Tracking Systems 6 What is Confocal Microscopy? 61 How the Corneal Tissues are Affected in Confocal Microscopy Procedure 62 LASIK vs Incisional Keratotomy 6 Results 62 The Importance of Confocal Microscopy to the CHAPTER 2 Sands of Sahara’s Syndrome 63 How to Prevent Sands of Sahara Syndrome 63 FUNDAMENTALS ON CHAPTER 4 CORNEAL TOPOGRAPHY Introduction: Human Optics and the PREDICTIVE FORMULAS FOR LASIK Normal Cornea 9 Instruments to Measure the Corneal Surface 10 The Predictive Formulas Main Components 65 Causes of Artefacts of the Corneal Developing Individualized Predictive Formulas 65 Topography Map 14 The Healing Pattern of the Cornea 65 Understanding and Reading Corneal Topography15 Excimer Laser Ablation Nomograms for: Topographic Scales 16 Photorefractive Keratectomy 66 Computer Displays: Presentation of LASIK 66 Topographic Information 16 Predictive Formulas for LASIK with: 67 Special Software Applications and Displays 23 VISX S2 SmoothScan 68 ATLAS OF CORNEAL TOPOGRAPHY 31-42 Chiron Technolas 116 69 TOPOGRAPHERS NOW AVAILABLE 43 Technolas 217 Excimer Laser 70 vii CONTENTS SECTION II - LASIK HIGHLIGHTS OF SURGICAL INSTRUMENTATION (MICROKERATOMES) AND SURGICAL TECHNIQUES CHAPTER 5 CHAPTER 9 MICROKERATOMES LIMITATIONS AND CONTRAINDICATIONS OF LASIK Different Mechanical Components 78-80 Applanation Lenses 80 Preoperative Evaluation 127 Tonometer 80 Special Cases 134 Guidelines for Microkeratome Use 80 LASIK after IOL Implantation 134 Astigmatism Inductions by Hinge Ablation 86 Bilateral Simultaneous vs. Sequential Surgery 134 Free Cap 87 LASIK after RK 134 The Main Microkeratomes: 87-99 Alternatives to LASIK 135 Outline PRK 135 Description Refractive Lensectomy 135 How to Use Them Phakic Intraocular Lens 136 Thermokeratoplasty (LTK) 136 CHAPTER 6 AUTOMATIC CORNEAL SHAPER CHAPTER 10 Note from the Editor-in-Chief 101 Different Components & Instrumentation 101-3 LASIK SURGICAL TECHNIQUE Surgical Technique Step by Step 104-5 Troubleshooting 105 Patient Selection 139 Care, Handling & Sterilization 107 PREOPERATIVE PREPARATION 140 The Patient 140 CHAPTER 7 The Instruments 140 The Laser 140 DOWN UP LASIK The Keratome 141 The Surgeon 142 Setting up of the Hansatome 109 PREPARATION IN OPERATING ROOM 142 Care, Maintenance & Sterilization 112 Draping 142 Troubleshooting 114 Speculum 142 Surgical Technique Step by Step 114 Positioning the Patient 143 Advantages & Disadvantages 114 THE LASIK PROCEDURE 143 Marking 143 CHAPTER 8 Placement of the Suction Ring 143 The Microkeratome Cut 144 Laser Ablation 145 ALL LASER LASIK With the Replacing the Flap 146 Pulsion FS Laser Intraoperative Bleeding in LASIK 148 Postoperative Care 150 Preoperative Evaluation 119 Home Care Instructions 150 Surgical Logistics 120 Surgical Technique Step by Step 120-4 Postoperative Care 125 viii CONTENTS CHAPTER 11 Maintain Consistent Hydration 153 Perform the Appropriate Ablation 154 PEARLS IN LASIK TECHNIQUE Prevent and Remove Debris from Beneath the Flap 155 Properly Align the Flap 156 Patient Counseling 151 Achieve Good Flap Adhesion 157 Achieving Adequate Exposure 151 Avoid and Treat Loose Epithelium 157 Achieve and Confirm Adequate Suction 152 Conclusion 158 Create a Complete Flap 153 SECTION III LASIK IN COMPLEX CASES CHAPTER 12 Compound Myopic Astigmatism 188 Simple Hyperopic Astigmatism 188 Compound Hyperopic Astigmatism 188 LASIK FOR HYPEROPIA Mixed Astigmatism 189 Negative Cylinder Ablation to Treat Technique, Safety and Efficacy 161 Mixed Astigmatism 189 Hyperopic Correction using the Excimer Laser 162 Positive Cylinder Ablation to Treat Patient Selection and Preoperative Considerations163 Mixed Astigmatism 190 Technique 164 Bitoric Ablation to Treat Mixed Astigmatism190 Clinical Results 164 Results of Lasik in Mixed Astigmatism 192 Secondary Hyperopia 165 Conclusion 192 Hyperopia with Astigmatism 165 CHAPTER 15 CHAPTER 13 RELASIK LASIK FOR IRREGULAR ASTIGMATISM Procedure 195 Results 196 Etiology of Irregular Astigmatism 169 Discussion 198 Diagnosis 170 Clinical Classification 170 CHAPTER 16 Corneal Topography Patterns 170 1. Irregular astigmatism with defined pattern 170 LASIK AFTER RK AND PRK 2. Irregular astigmatism with undefined Results of LASIK After RK and PRK 201 pattern 171 RK Group 202 Preoperative Evaluation 171 PRK Group 203 Treatment of Irregular Astigmatism 175 Discussion 204 Surgical Techniques with Excimer Laser 175 Automated Anterior Lamellar Keratoplasty 184 CHAPTER 17 Intracorneal Ring Segments (INTACS) 184 Other Non-Surgical Procedures 184 LASIK AFTER PENETRATING Contact Lens Management 184 KERATOPLASTY Eligible Patients 208 CHAPTER 14 Timing of Surgery 208 Surgical Technique 209 LASIK IN MIXED ASTIGMATISM Postoperative Treatment 209 Risks and Possible Complications 210 Classification 187 Results 210 Simple Myopic Astigmatism 187 Conclusions 212 ix