Ординатура / Офтальмология / Английские материалы / Mastering Corneal Collagen Cross-linking Techniques (C3-R CCL CxL)_Garg, Kanellopoulos, O'Brart, Lovisolo, Pinelli_2008

Mastering Corneal Collagen

Cross-linking Techniques

(C3-R/CCL/CxL)

System requirement:

•Windows XP or above

•Power DVD player (Software)

•Windows media player 10.0 version or above (Software)

Accompanying DVD ROM is playable only in Computer and not in DVD player.

Kindly wait for few seconds for DVD to autorun. If it does not autorun then please do the following:

•Click on my computer

•Click the DVD drive labelled JAYPEE and after opening the drive, kindly double click the file Jaypee

Published by

Jitendar P Vij

Jaypee Brothers Medical Publishers (P) Ltd

Corporate Office

4838/24 Ansari Road, Daryaganj, New Delhi - 110002, India, +91-11-43574357

Registered Office

B-3 EMCA House, 23/23B Ansari Road, Daryaganj, New Delhi 110 002, India

Phones: +91-11-23272143, +91-11-23272703, +91-11-23282021, +91-11-23245672, Rel: +91-11-32558559 Fax: +91-11-23276490, +91-11-23245683 e-mail: jaypee@jaypeebrothers.com, Website: www.jaypeebrothers.com

Branches

2/B, Akruti Society, Jodhpur Gam Road Satellite

Ahmedabad 380 015, Phones: +91-79-26926233, Rel: +91-79-32988717

Fax: +91-79-26927094, e-mail: ahmedabad@jaypeebrothers.com

202 Batavia Chambers, 8 Kumara Krupa Road, Kumara Park East

Bengaluru 560 001, Phones: +91-80-22285971, +91-80-22382956,

+91-80-22372664, Rel: +91-80-32714073

Fax: +91-80-22281761, e-mail: bangalore@jaypeebrothers.com

282 IIIrd Floor, Khaleel Shirazi Estate, Fountain Plaza, Pantheon Road Chennai 600 008, Phones: +91-44-28193265, +91-44-28194897,

Rel: +91-44-32972089, Fax: +91-44-28193231, e-mail: chennai@jaypeebrothers.com

4-2-1067/1-3, 1st Floor, Balaji Building, Ramkote Cross Road

Hyderabad 500 095, Phones: +91-40-66610020, +91-40-24758498, Rel:+91-40-32940929 Fax:+91-40-24758499, e-mail: hyderabad@jaypeebrothers.com

No. 41/3098, B and B1, Kuruvi Building, St. Vincent Road

Kochi 682 018, Kerala, Phones: +91-484-4036109, +91-484-2395739, +91-484-2395740 e-mail: kochi@jaypeebrothers.com

1-A Indian Mirror Street, Wellington Square

Kolkata 700 013, Phones: +91-33-22651926, +91-33-22276404, +91-33-22276415, Rel: +91-33-32901926

Fax: +91-33-22656075, e-mail: kolkata@jaypeebrothers.com

Lekhraj Market III, B-2, Sector-4, Faizabad Road, Indira Nagar Lucknow 226 016, Phones: +91-522-3040553, +91-522-3040554 e-mail: lucknow@jaypeebrothers.com

106 Amit Industrial Estate, 61 Dr SS Rao Road, Near MGM Hospital, Parel

Mumbai 400012, Phones: +91-22-24124863, +91-22-24104532,

Rel: +91-22-32926896 Fax: +91-22-24160828, e-mail: mumbai@jaypeebrothers.com

“KAMALPUSHPA” 38, Reshimbag, Opp. Mohota Science College, Umred Road Nagpur 440 009 (MS), Phone: Rel: +91-712-3245220,

Fax: +91-712-2704275, e-mail: nagpur@jaypeebrothers.com

USA Office

1745, Pheasant Run Drive, Maryland Heights (Missouri), MO 63043, USA, Ph: 001-636-6279734 e-mail: jaypee@jaypeebrothers.com, anjulav@jaypeebrothers.com

Mastering Corneal Collagen Cross-linking Techniques

© 2009, Editors

All rights reserved. No part of this publication and Video DVD Rom should be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the editors and the publisher.

This book has been published in good faith that the material provided by contributors is original. Every effort is made to ensure accuracy of material, but the publisher, printer and editors will not be held responsible for any inadvertent error(s). In case of any dispute, all legal matters are to be settled under Delhi jurisdiction only.

First Edition: 2009

ISBN 978-81-8448-493-9

Typeset at JPBMP typesetting unit

Printed at Ajanta Press

Dedicated to

–My Respected Param Pujya Guru Sant Gurmeet Ram Rahim Singh Ji for his blessings and motivation.

–My Respected Parents, teachers, my wife Dr. Aruna Garg, son Abhishek and daughter Anshul for their constant support and patience during all these days of hard work.

–My dear friend Dr. Amar Agarwal, a renowned International Ophthalmologist for his constant support, guidance and expertise.

—Ashok Garg

–All patients affected by Keratoconus, in the hope that a near future will offer a solution avoiding for many of the them the corneal transplant.

—Roberto Pinelli

–My parents, the endless and willing teachers and my family : my wonderful wife Nathalie, and our children: Alexander, Angelina and Konstantine.

—A John Kanellopoulos

–My wife Elizabeth.

—David O. Brart

–My kids Alessandro and Luca Ghigo, the lastcomers, two potentially brilliant researchers in the field of nanotechnology.

—Carlo Francesco Lovisolo

Foreword

This is one of the most exciting times for ophthalmology in general, and cornea and refractive surgery in particular. The breakthroughs over the last several years are changing the way we approach the cornea and offering our patients new and exciting opportunities for visual rehabilitation. At present, there is no technology with more promise than corneal collagen cross-linking. It combines two relatively mundane entities: riboflavin or vitamin B2, which is a naturally occurring photosensitizer found in all human cells, and ultraviolet light. A remarkable change occurs in the cornea stroma when riboflavin and ultraviolet light react together at the right concentrations and for the correct duration. The crosslinking of the corneal collagen fibrils strengthens the biomechanical properties of the cornea with a resultant increase in the tensile strength of the collagen fibrils. Although

there may also be a slight flattening of the cornea, the most important effect of the cross-linking is that it stabilizes the corneal curvature and prevents further steepening and bulging of the corneal stroma. There is no significant change in the refractive index or the clarity of the cornea. The clinical applications of collagen cross-linking offers for the first time, a treatment for one of the most common corneal disorders, keratoconus, as well as the most dreaded complication of corneal refractive surgery, ectasia.

Corneal ectasia is a rare but well-described complication of laser in-situ keratomileusis (LASIK) and an even more rare complication of photorefractive keratectomy (PRK). Over the last several years, risk factors for ectasia have been identified, which include high myopia, deep ablations, reduced residual corneal bed, young age, thin pachymetry, and most importantly, pre-operative corneal irregularity. However, ectasia may occur with no risk factors despite our best attempts to prevent it. Corneal ectasia is a condition in which the cornea is weakened by LASIK or PRK so that it protrudes irregularly and bows outward. This creates progressive steepening and thinning of the cornea, loss of uncorrected visual acuity, and loss of best spectacle-corrected visual acuity. The final results of ectasia may be as minimal as the need for the patient to return to the use of glasses. However, many patients may require a lifetime of rigid contact lenses, intracorneal ring segments, or penetrating keratoplasty for visual rehabilitation. Collagen cross-linking may arrest the progression of ectasia and when combined at the same time or subsequently with topographic or wavefront guided photoablation, may return uncorrected visual acuity. Patients at risk for ectasia may be prophylactically treated to prevent its occurrence. The elimination of corneal ectasia as a risk of LASIK and PRK has the potential to open an era of refractive surgery where the most dreaded complication has been eliminated.

Keratoconus is a naturally occurring ocular condition similar to ectasia and characterized by progressive thinning and steepening of the central cornea. Keratoconus frequently affects patients in their teens and early twenties, progresses over the course of a decade, and leaves patients visually handicapped, often with high myopia, irregular astigmatism, and significant loss of best corrected visual acuity. Rigid contact lenses can be used to improve visual acuity in many patients, but keratoconus frequently progresses to the point that corneal transplantation is required to restore useful vision. It may recur following corneal transplantation and require further transplant surgery. The incidence of keratoconus in the general population is estimated to be approximately one in 2000 and in the United States, keratoconus is the third most common indication for penetrating keratoplasty. Corneal transplantation has undergone remarkable improvements, but it still has inherent risks