The Art of Phacoemulsification

The ArThe ArThe ArThe ArThe Art oft oft oft oft ofPhacoemulsificationPhacoemulsificationPhacoemulsificationPhacoemulsificationPhacoemulsification


Editors

Keiki R Mehta MD MBBS DOMS MS (Ophth) FORCE (India) DO (Ireland) DO (London) FRSH (London) FIOS (USA)

Medical Director: Mehta International Eye InstituteChief: Ophthalmic Services, Colaba Eye Hospital

Chief: Surgical Services, Netra Rukshak, Rural Eye Services Wing, Mumbai, IndiaHead: Eye Department, Breach Candy Hospital and Research Centre, Mumbai

Hon Ophthalmic Consultant Surgeon: Armed Forces, IndiaHon Ophthalmic Consultant to the Governor of Maharashtra

Past President: All India Ophthalmological Society, Intraocular Implant Society, India

and

John J Alpar MD FACS FICS PADiplomate: American Board of Ophthalmology

Diplomate: Hungarian Board of OphthalmologyClinical Professor: Texas Tech University School of Medicine

Medical Director: Panhandle Ophthalmological Research Foundation, Texas, USAFellow: American Academy of Ophthalmology, Saint Luke Eye Institute

Amarilo, Texas, USA

JAYPEE BROTHERSMEDICAL PUBLISHERS (P) LTD

New Delhi

Published byJitendar P VijJaypee Brothers Medical Publishers (P) LtdB-3 EMCA House, 23/23B Ansari Road, DaryaganjPost Box 7193, New Delhi 110 002, IndiaPhones: 3272143, 3272703, 3282021 Fax: 011-3276490E-mail: [email protected] our web site: http://www.jpbros.20m.com

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The Art of Phacoemulsification

2001, Editors

All rights reserved. No part of this publication should be reproduced, stored in a retrievalsystem, 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 on good faith that the material provided by editors is original.Every effort is made to ensure accuracy of material, but the publisher, printer and editors willnot be held responsible for any inadvertent error(s). In case of any dispute, all legal mattersto be settled under Delhi jurisdiction only.

First Edition: 2001

ISBN 81-7179-790-3

Publishing Director: RK Yadav

Typeset at JPBMP typesetting unitPrinted at Gopsons Paper Ltd., Noida

Contributors

Alpar John J MD FACS FICS PAClinical ProfessorTexas Tech University School of MedicineMedical DirectorPanhandle Ophthalmological ResearchFoundation, Texas, USAFellowAmerican Academy of OphthalmologySaint Luke Eye InstituteAmarilo, Texas, USA

Fine Howard I MDClinical Assistant ProfessorOregon Health Sciences UniversityPortland, OregonOregon Eye Assocciates, EugeneOregon, USA

Richard S Hoffman MDOregon Eye Associates, Eugene, Oregon, USA

Fry Luther L MDDirector and ChiefFry Associates PA/Ophthalmology310 East Walnut, Garden City, Kansas, USA

Jonathan P Ellant MDChiefSt Clares Hospital and Health Care CenterAssistant ProfessorMt Sinai School of MedicineNew York, USA

Luis W Lu MD FACSInstructorUniversity of Pittsburgh School of MedicineELK County Eye ClinicCenter for Advanced Eye CareSt. Marys, Pennsylvania, USA

Garry P Condon MDDirector, Division of GlaucomaAllegheny General HospitalMCP Hahnaman UniversityPittsburgh, Pennsylvania, USA

Louis D Nichamin MDMedical DirectorLaurel Eye ClinicBrookville, Pennsylvania, USA

Masket Samuel MDClinical ProfessorJules Stein Eye InstituteUCLA, Los Angeles, USA

Allen David E MD FRCOphthConsultant OphthalmologistCity Hospitals, SunderlandSunderland Eye InfirmaryQueen Alexandra Road, Sunderland, UK

Arnott Eric J MD DO FRCS FRCOphthConsultant OphthalmologistArnott Eye Centre, Trottsford FarmHeadley, Nr Brandon Hamshire, UK

Packard Richard MD FRCS FRCOphthOphthalmic SurgeonPrince Charles Eye UnitWindsor, UK

Durval Carvalho M MDChiefCataract DepartmentCentro Brasileiro de Cirurljia, de Olhros (CBCO);MemberConselho da Sociedade Brasileria deCataracta, Brazil

Durval Carvalho M Jr MDDoctorate, Departamento de Oftalmologia daUniversidade Sao Paulo (USP)Member, Departamento de Oftalmologia daUniversidade Federal de Goias (UFG), Brazil

Arshinoff Steve A MD FRCSCOphthalmic SurgeonYork Finch Eye Associates2115 Finch Avenue W, Suite 316, Toronto,Ontario, Canada

Davis Peter L MD, FRCS (C)Senior OphthalmologistNorth Okanagan Health DistrictVernon BC V1T 2M9, Canada

Aron-Rosa Danielle MDOphthalmic Surgeon28 Ave, Raphael, Paris, France

Joseph Leon A MDConsulting SurgeonPolyclinique Comiti,Dept of Ophthalmology20000, Ajaccio, France

Claude S Leon MDFrance

Emilio Balestrazzi MDProfessor, Dipartimento Di DisciplineChirurgiche, Via Vettoio, Blocco 117A, 6710Coppito (AQ), Italy

Leopoldo Spadea MDUniversity of LAQuilaS Salvatore Hospital, LAQuila, Italy

Luigi Mosca MDUniversity of LAQuilaS Salvatore Hospital, LAQuila, Italy

Oshika Tetsuro MDOphthalmic SurgeonUniversity of Tokyo School of Medicine7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan

Alio Jorge L MD PhDProfessor and Chairman of Ophthalmology,Medical DirectorInstituto Oftalmologico de AlicanteIOIS General Secretary, AVDADEDenia, Alicante, Spain

Enrique Chipont MD PhDOphthalmic SurgeonInstituto Oftalmologico de AlicanteIOIS General Secretary, AVDADEDenia, Alicante, Spain

Agarwal Amar MS FRCS FRCOphth (Lon)Consultant Ophthalmic SurgeonDr Agarwals Eye Institute13 Cathedral Road, Chennai, India

Agarwal Athiya MD (Path) FRSH (Lon) DOConsultant Ophthalmic SurgeonDr Agarwals Eye Institute13 Cathedral Road, Chennai, India

Agarwal Jaiveer MDDirector and ChiefDr Agarwals Eye Institute13 Cathedral Road, Chennai, India

Agarwal Sunita MD FSVH (WG) FRSH (Lon) DODirector and ChiefDr Agarwals Eye Institute15 Eagle Street, Bangalore, India

Agarwal T MDConsultant Ophthalmic SurgeonDr Agarwals Eye Institute13 Cathedral Road, Chennai, India

Col Akhil Bharadwaj MDChief Eye Surgeon, Armed Forces, Asvini, ColabaMumbai, India

Dada Vijay K MD DOMSChief and ProfessorDr Rajendra Prasad Centre for OphthalmicSciences, All India Institute of Medical SciencesNew Delhi, India

Namrata Sharma MDDr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical SciencesNew Delhi, India

Tanuj DadaDr Rajendra Prasad Centre for OphthalmicSciences, All India Institute of Medical SciencesNew Delhi, India

Kapoor Shashi MDConsulting Ophthalmic SurgeonKapoor Eye Clinic, 409 Om ChambersKemps CornerMumbai, India

vi THE ART OF PHACOEMULSIFICATION

Kelkar Shrikant MDDirector and ChiefNational Institute of Ophthalmology1187/30, Ghole Road, Shivaji NagarPune, India

Lahane Tatyarao P MDProfessor and HeadGrant Medical CollegeJJ Group of HospitalsMumbai, India

Maniar Ranjit H MDHead, Shushrusha Hospital, MumbaiHonorary Ophthalmic ConsultantJankikund Hospital, Chitrakoot

Mehta Cyres K MDConsultant OphthalmologistMehta International Eye InstituteColaba Eye HospitalMumbai, India

Mehta Keiki R MDMedical DirectorMehta International Eye InstituteChief, Ophthalmic ServicesColaba Eye HospitalChief, Surgical ServicesNetra Rukshak: Rural Eye Services WingHead, Eye DepartmentBreach Candy Hospital and Research CentreSea Side, 147 Shahid Bhagat Singh Road,Mumbai, India

Mody Kirit K MD FRCSMedical DirectorSalil Eye Clinic & Contact Lens Centre,506 Om Chambers, 123 August Kranti Marg,Kemps Corner, Mumbai,Hon ProfessorGrant Medical CollegeHon Eye SurgeonGT General HospitalConwest Jain Clinic HospitalSmt. Lilavati HospitalMumbai, India

Murthy Gowri J MDConsultant Ophthalmic SurgeonPrabha Eye Clinic504, 40th Cross, 8th BlockJayanagar, Bangalore, India

CONTRIBUTORS vii

Murthy KR MDConsultant Ophthalmic SurgeonPrabha Eye Clinic504, 40th Cross, 8th BlockJayanagar, Bangalore, India

Sachdev Mahipal S MDCornea Fellowship (USA),Phacoemulsification, Excimer Laser, Corneaand Contact Lens SpecialistNew Delhi Centre for SightA-23 Green Park, Aurobindo MargNew Delhi, India

Pradeep VenkateshPool OfficerDr Rajendra Prasad Centre for OphthalmicSciences, All India Institute of Medical SciencesNew Delhi, India

Shroff Noshir M MDMedical DirectorShroff Eye CentreA-9 Kailash ColonyNew Delhi, India

Ranjan Dutta MDShroff Eye CentreA-9, Kailash ColonyNew Delhi, India

Gurpreet Singh DOShroff Eye CentreA-9, Kailash ColonyNew Delhi, India

Vajpayee Rasik B MDProfessorDr Rajendra Prasad Centre for OphthalmicSciences, All India Institute of Medical SciencesNew Delhi, India

Vishal Gupta MDDr Rajendra Prasad Centre for OphthalmicSciences, All India Institute of Medical SciencesNew Delhi, India

Inderjit SinghProfessor and HeadCoffs Harbour Hospital69 Albany Street, Coffs HarbourNew South Wales 2450, Australia

Preface

Advances in the field of Cataract surgery and intraocular implantation over the last50 years have been astonishing. Phacoemulsification, had a slow beginning, but inthe last 5 years has exploded forwards. Improvements in technique are increasing ata rapid pace, as the advantages of small incision cataract surgery, the instant patientrehabilitation physical and visual are obvious. Nevertheless, the ultimate expressionof minimal patient inconvenience and minimal delay in resumption of patients lifestyleis the legacy of Phacoemulsification

It was in the winter of 1989 when one of us (KRM) performed our first cataractoperation utilizing Phacoemulsification. From that moment onwards, we had no doubtsthat this was a winning combination and in future all cataract operations would beperformed with this technique and with this technique only. The procedure has changedsince then. It has evolved and improved significantly. The technique has been perfected.The technology has progressed. The quality of the surgery is now virtuallyunsurpassable, and most importantly, surgeons all over the world now trust and relyon the Phacoemulsification technique.

Old concepts change, giving way to new ideas, as fresh advances in all fields ofscience and medicine forge ahead. Phacoemulsification surgery and its complicationsare no exception. We have tried to be highly selective in modifying old concepts andincluding not only those changes that have widespread acceptance but also haveincluded newer developments which will make their mark in the new millennium.

The visual needs of patients are dictated by their circumstances, which include age,occupation, leisure interests, and their independence. As an adviser to a patient, theophthalmic surgeon must consider the individual requirements of the patient andbalance these against the potential risks of surgical treatment. As a surgeon, his orher attitude is tempered by his or her experience, knowledge of the experiences ofothers and confidence in his or her own ability to achieve perfection of results thatshould shine as a beacon of excellence in the community.

The primary intent of the book, The Art of Phacoemulsification is to provide anintroduction to the subject of Phacoemulsification as well as the framework on whichcould be constructed the study of that discipline. Presentation of the material beginswith the most fundamental aspects and builds up successive levels of knowledge.

x THE ART OF PHACOEMULSIFICATION

The purpose of this volume is to consider, in-depth, all aspects of Phacoemulsi-fication. It is hoped that it will provide the ophthalmic surgeon who intends tocommence Phacoemulsification surgery with the information necessary for effectiveand safe participation. For those who are already in this exciting field, this book shouldprovide a useful source of reference. It is designed to consider both the problem andits solution. The solution has many variations but all should take into account thevulnerable tissues that are required to be protected during surgery.

Every step of Phacoemulsification procedure is critical in determining the finalsurgical outcome. The surgery is a sequence of steps, each fundamentally importantto the entire procedure. Thus while this treatise has designed to allow the readersto refine and enhance their surgical technique, it should reveal the latest advancesin both the science and art of the modern technique of Phacoemulsification cataractsurgery.

The Art of Phacoemulsification has been conceptualized by some of the foremostcataract surgeons in the world. These contributing authors share their preferredtechniques and ideas presenting the most advanced methods of surgical procedures,the newest equipment available, and their methods of managing the cataract patient.

It will undoubtedly be apparent to many readers that some subjects have receiveda greater emphasis than others. These represent to some extent, our special interestsand experiences.

The major task of keeping abreast of the dynamic changes in Phacoemulsificationsurgery is nearly nondescribable. No single surgeon can speak authoritatively aboutevery subject. Nor can every aspect of the subject be covered. This book covers a fairset of surgical methods and complications. Each chapter thus is an insight into thetechnique suitable for each surgeon and most importantly; the technique, which bestsuits that particular case. Each surgeon provides a detailed description directly fromhis or her experience of the more important Phacoemulsification techniques and hisor her reaction to each new development.

All contributors are aware that the production of a book having such a large volumeof information, takes many months. Time and tide wait for none and certainly; thefast changing field of Phacoemulsification has new developments literally every day.The subject is developing rapidly, but it is our hope that the wealth of experienceincorporated here will be valuable not only in the present time, but also for the future.

This book is a multi-authored text and is, as such, abounds in differing literarystyles. The editors have sought to provide a level of organizational conformityand scientific balance without sacrificing the originality and style of the individualauthors. A distinctive feature of this book is the diversity of its many outstandingcontributors.

Probably the outstanding characteristic of this book is the editors ability to selectcritically important contributions to the management of cataract problems. Theseare analyzed and evaluated based on their vast experiences as ophthalmic surgeonsand consultants.

PREFACE xi

We would like to thank the contributing authors who are by their own right,considered the outstanding leaders in the field of Cataract surgery. This book wouldbe non-existent without the devoted and tireless efforts of these physicians whocontributed to this text while maintaining a rigorous daily practice.

With promising laser techniques on the horizon, non-invasive Cataract surgery maysoon be feasible. Many of these exciting developments are arriving so rapidly thateven senior consultants in the field are often hard-pressed to keep up with the latestadvances. What the future holds for us is difficult to portend, but one thing is certain,it will be exciting.

Finally, the editors wish to take the liberty to express their deep appreciation toJaypee Brothers Medical Publishers, Indias premier medical publication company, fortheir unflagging encouragement and tireless assistance in the production of The Artof Phacoemulsification. Mr Jitender P Vij, the Managing Director of Jaypee is truly agem of a man, not only for his great faith that I would, one day, finally finish thisepitome, but also for the general all-round editorial assistance given, the well laid-out pages and the crisp photographs which have made it, truly, a world class book.

Keiki R MehtaJohn J Alpar

Contents

1. Commencing Phacoemulsification: The Basics ..................................................1Keiki R Mehta, Ranjit H Maniar

2. The Phacomachine ...................................................................................................15Mahipal S Sachdev, Pradeep Venkatesh

3. New Phacomachines Offer More Control .........................................................32David E Allen

4. Cavitating Microbubbles Create Shock Waves thatEmulsify Cataract ......................................................................................................45Peter L Davis

5. Local Anesthesia .......................................................................................................51KR Murthy

6. Ocular Anesthesia for Small-IncisionCataract Surgery ........................................................................................................58Samuel Masket

7. The Limbal Incision ................................................................................................64Shashi Kapoor

8. No Anesthesia Cataract Surgery ..........................................................................76Amar Agarwal, Athiya Agarwal, Sunita Agarwal

9. Clear Corneal Cataract Surgery............................................................................86Keiki R Mehta, Cyres K Mehta

10. Capsulorrhexis: A Beginners Guide ..................................................................94Shashi Kapoor

11. Capsulorrhexis: Principles and Advanced Techniques ................................103Shrikant Kelkar

12. Hydrodissection and Hydrodelineation ........................................................... 112Keiki R Mehta, Cyres K Mehta

13. Phacoemulsification: The Quadrantic Cracking, Chopping andStuffing Technique ................................................................................................. 118Noshir M Shroff, Ranjan Dutta, Gurpreet Singh

14. Current Phacoemulsification Techniques .........................................................130Richard Packard

15. Phaco Slice and Separate .....................................................................................154Steve A Arshinoff

16. Cataract Extraction and Lens Implantation:The Implosion Technique ....................................................................................161Eric J Arnott

17. Phacoemulsification in Special Situations ......................................................170Rasik B Vajpayee, Tanuj Dada

18. Zen in the Art of Phaco ......................................................................................177Jonathan P Ellant

19. My Personal Technique of Vertical HubbingPhacoemulsification ................................................................................................187Keiki R Mehta

20. Innovative Nucleotomy Techniques ..................................................................204Vijay K Dada, Namrata Sharma, Tanuj Dada

21. Phacoemulsification in White Cataracts ..........................................................214Rasik B Vajpayee, Tanuj Dada, Vishal Gupta

22. Phacoemulsification in Difficult Cases ............................................................223Inderjit Singh

23. Irrigation and Aspiration following Phacoemulsification ..........................246Keiki R Mehta, Cyres K Mehta

24. Foldable Intraocular Implants ............................................................................253Vijay K Dada, Namrata Sharma, Tanuj Dada

25. History of Lens Implantation .............................................................................263Eric J Arnott

26. Implantation Techniques of Acrylic Foldable Intraocular Lensand its Clinical Results ........................................................................................268Tetsuro Oshika

27. The Mini-loop Plate and Accommodating Lenses .......................................288J Stuart Cumming

28. Suprahard Cataracts: Their Evaluation and Management .........................299Keiki R Mehta, Kirit K Mody

xiv THE ART OF PHACOEMULSIFICATION

29. Stretch Pupilloplasty for Small Pupil Management inCataract Surgery ......................................................................................................314Luther L Fry

30. Management of Glaucoma in Cataract Patients ...........................................322Gowri J Murthy, KR Murthy

31. Phacoemulsification in the Previously Filtered Eye ....................................329Garry P Condon, Luis W Lu

32. Phacoemulsification in Patients with Significant Astigmatism................344Luis W Lu, Louis D Nichamin

33. Cataracts in Patients with Uveitis .....................................................................353Enrique Chipont, Jorge L Alio

34. Corneal Endothelium and its Protection inPhacoemulsification ................................................................................................365Keiki R Mehta, Cyres K Mehta

35. Phacoemulsification in the Presence of Pseudoexfoliation:Challenges and Options .......................................................................................381I Howard Fine, Richard S Hoffman

36. Phacoemulsification in Severe Chronic ObstructivePulmonary Disease .................................................................................................388I Howard Fine, Richard S Hoffman

37. The Prevention of Complications and their Management inPhacoemulsification ................................................................................................393Keiki R Mehta

38. Management of Posterior Chamber IOL Capture ........................................415Durval M Carvalho, Durval M Carvalho Jr

39. IOL Scleral Fixation in Aphakic Eyes .............................................................422Durval M Carvalho, Durval M Carvalho Jr

40. Phakonit and Laser Phakonit .............................................................................446Amar Agarwal, Athiya Agarwal, Sunita Agarwal

41. Pharmacology of Intraocular Solutions and Drugs used inPhacoemulsification ................................................................................................453Keiki R Mehta, TP Lahane

42. Triple Procedure with Phocoemulsification before Trephination ............462Emilio Balestrazzi, Leopoldo Spadea, Luigi Mosca

43. Multiport Phaco Tip: A Safer and More EffectiveTraining Device for Phacoemulsification ........................................................471Keiki R Mehta

CONTENTS xv

44. Intraocular Lenses Dislocated into the Vitreous ..........................................479John J Alpar

45. Favit: A New Technique to Manage Dropped Nuclei ................................486Amar Agarwal

46. Laser Phaco Cataract Surgery .............................................................................493Sunita Agarwal, J Agarwal, T Agarwal

47. Endoscopy-Assisted Phacoemulsification .........................................................500Claude S Leon, Joseph A Leon, Danielle Aron-Rosa

48. Phacoemulsification: The Eye Camp Way ......................................................507Keiki R Mehta, Kirit K Mody, Ranjit H Maniar, Cyres K Mehta, Akhil Bharadwaj

Index ............................................................................................................................ 529

xvi THE ART OF PHACOEMULSIFICATION

The primary intent of this book is to provide an introduction to the subject of Phacoemulsification. Presentation of thematerial begins with the most fundamental aspects and builds up successive levels of knowledge. Every step ofPhacoemulsification procedure is critical in determining the final surgical outcome. The surgery is a sequence of steps,each fundamentally important to the entire procedure.

This book has been prepared by some of the foremost cataract surgeons in the world. These contributing authorsshare their preferred techniques and ideas presenting the most advanced methods of surgical procedures, the newestequipment available, and their methods of managing the cataract patient.

This is a uniquely up-to-date book which covers scientific principles and current clinical and research trends, withpractical information on patient assessment, variable surgical techniques, clinical results and the identification, avoidanceand the management of complications.

Keiki R Mehta, one of Indias foremost cataract surgeons, commenced intraocular implants inIndia in 1972, and developed in 1975, for the first time in the world, a soft HEMA Intraocular implant.He initiated Phacoemulsification for cataract surgery in 1979 and is known as the Father ofPhacoemulsification in India.

An exceptional surgeon, he has operated live in workshops, teaching phaco all over India. Dr Mehtais a popular teacher in great demand at conferences and symposia and has written many scientificbooks and published scientific papers, both at national and international level. He has been awardedeight gold medals and innumerable oration awards from national / international bodies. Extremelyinnovative, he has been on the cutting edge of technology and has devised multiple new techniquesand instruments.

John J Alpar is an exceptionally skilled surgeon , edited an extremely popular book, which literallybecame in the 1990s, a bible for implant surgeons, termed Fechners Intraocular Lenses,. WithProfessor Fechner of Hanover, Germany, Dr Alpar produced a book, impressive by its well-organizedstructure, its wealth of information, its practicality and the superb technique of presentation.

A prodigious speaker and author, Dr Alpar has delivered 178 lectures, published 158 scientificarticles , 11 chapters, 4 books and attended over 320 meetings. Widely traveled, he is a life memberof the All India, Mexican and Hungarian Ophthalmological Societies, the Indian and Canadian ImplantSocieties, and is member of the Medical Societies in Peru, Japan, France. Dr John Alpar is respectedworldwide for the quality of his work, the scope of his knowledge, his sharp intellect and brillianceand his keen, incisive analysis of facts.

Contributors include Alpar John J Fine Howard I Fry Luther L Jonathan P Ellant Luis Lu W Masket Samuel Allen David E ArnottEric J Richard Packard Durval Carvalho M Durval Carvalho M Jr Arshinoff Steve A Davis Peter L Aron-Rosa Danielle Joseph Leon A Emilio Balestrazzi Oshika Tetsuro Alio Jorge L Enrique Chipont Agarwal Amar Agarwal Athiya Agarwal Jaiveer Agarwal Sunita Agarwal T Col Akhil Bharadwaj Dada Vijay K KapoorShashi Kelkar Shrikant Lahane Tatyarao P Maniar Ranjit H

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INTRODUCTION

Phacoemulsification is a superb technique, but to be able to conduct it comfortablyand effectively all the appliances, solutions and even the personnel in the theatreneed to be properly located and trained to respond to any situation which mayarise. It is imperative that the surgeon understands the basic applications of eachof the different requirements. For maximum efficiency and safety, proper locationand arrangements, right from the operating table, the microscope, the surgeonschair, the instruments on the trolley, the placement of the staff nurse, the assistants,and even that of the wardboys, have to be carefully planned and worked out inadvance.

Phacoemulsification is an instrument-based surgery. It is also a high-pressuresurgery, with periods of calm alternating with high tension. Moreover, as such theremust be adequate space in the theatre so that effective and rapid movement whenand if required can take place smoothly. Too compact a theatre is a sure prescriptionfor disaster.

THE OPERATING ROOM: REQUIREMENTS AND NECESSITIES

The operating roomrequirements and necessities of primary importance is a properlydesigned and functioning operating room or theatre (Fig. 1.1). There are manyimportant points, which need to be considered. Some of them will be felt unnecessary,but the strength of any chain is dependent on the weakest link. Thus every linkhas to be given its importance and considered on its own merits.

CommencingPhacoemulsification:The Basics

Keiki R MehtaRanjit H Maniar

1

2 THE ART OF PHACOEMULSIFICATION

Lighting

Lighting often does not get the importance it deserves. It is important that the theatrecan be lighted up properly, but equally important can also be darkened adequately.

It should be lighted sufficiently with shadowless theatre lamps of adequate power(minimum 50,000 Lux lamps). Though most of the surgery is done under the operatingmicroscope, there are times when good peripherally focused lights are an advantageas for squint or oculoplasty surgery. Additional, movable goose-neck direct orfiberoptic side theatre lamps are a necessity with good illumination and are especiallygood for capsulorrhexis in hard opaque cataracts. In addition, in case the theatreis darkened, provision should be made for spot lighting of the instrument trolley,the phaco unit, life-support systems, anesthetic equipment, with a lighting deviceon a rheostat so that the intensity is adequate for the scrub and circulating nurseand the anesthetist to see the equipment clearly, but is not so bright as to blindthe surgeon. Many surgeons need a spot of light focusing on the operating tablein addition to the operating microscope lights.

General illumination of the theater is also an important requirement. Thoughthe powerful focused lights may be shut off, gentle illumination is needed in atheatre to allow for movement. Tube lights, ideally should never be used in thetheatre as they are very distracting especially when the flicker increases as the tubegets a little older. In addition the flicker fusion frequency of the operating stafftend to be affected by the tube light especially when they are tired after a longsession, increasing surgeon and staff irritability

Darkening the theatre enhances the contrast under the operating microscope andis extremely useful when doing a capsulorrhexis especially in a hard cataract. Whenthe main theatre is darkened, provision needs to be made to gently illuminate thefloor so that personnel can still move around without tripping on objects.

It is important that spot lighting should be kept off places where high reflectancestainless steel appliances and instruments are placed. This is to prevent extraneousglare from reflection from these shiny surfaces. The colors of the clothing wornby the operating room personnel should be soft and muted avoiding harsh colors.Pastel shades of blue, green or yellow are quite acceptable, however; red and ochershould be avoided

Air-conditioning and Ventilation

The ventilation of the room should be adequate and the air-conditioning sufficientto compensate for the number of personnel who are going to be in the room. Theair-conditioning vents should be so arranged that they do not allow the air to be blownover the operating surfaces and at the same time keep the theatre cool. The idealoperating temperature would vary from surgeon to surgeon, however, a goodcomfortable temperature level in India is 70o C. The ideal air-conditioning would beone-way, taking in air from outside, filtering it, cooling it, and then expelling it outagain after circulating through the operation theatre. Most theatres in India and inmost of the smaller hospitals and nursing homes would seem to have window- mounted

COMMENCING PHACOEMULSIFICATION: THE BASICS 3

air-conditioning. The size and number should be adequate to provide good coolingwith the air intake for fresh air always remaining open. It is very important that everyevening following surgery the filters of the air-conditioner should be washed and soakedin a dilute solution of Cetavalon for half an hour prior to being re installed in theair-conditioner. The position of the units should be such that they do not blow overthe sterile field, or blow directly onto the operating staff.

Noise Level in the Theatre

An operating theatre should be an oasis of calm. It is therefore important that theoperating room should be located in a quiet area of the hospital or facility, andaway from distracting sounds. It is essential that the windows be double-glazed(twin sheets of glass with an air-space between them) to keep the noise level downto a minimal level. It should be imperative that the operating staff learn from thebeginning that unnecessary talk be kept to a minimum level and communicationsas far as possible should be by hand signs. This would guarantee that the surgeon,and the staff enjoy adequate peace and quiet to be able to concentrate on doinga good job. Background soft music should always be played in the operating theatreas it defuses tensions. The music should neither have a harsh beat nor irregularcadences.

Electrical Power and Outlets

The power points in the operating theatre should use high-quality reputable switchesof an adequate output so that they are not overloaded and at the same time, goodcontacts are obtained between the plugs and the sockets. Often, even in so-called,Five Star facilities, it is seen that from a single outlet, using multipoint extensions,a number of lines are drawn. The wires then are left carelessly on the floor. Allpower points should be far away from the surgical field and preferably from acentral hanging pod so that one cannot accidentally trip over the wires. In caseit is required to trail a wire on the floor, it must be well protected with a maskingtape so it is not accidentally pulled out in the dark.

The power outlets should be rated at a sufficient level to comfortably run themedical equipment. Over loading of the points often leads to failure at a criticaltime during surgery. It is also imperative that fuses be provided for every mediaoutlet in the theatre of the self-adjusting type which could be reset simply by pushingin a button rather than the older wire-looped fuses. Sensitive instruments like aphacoemulsification machine and life-support evaluation systems (cardiac monitoror oxygen saturation monitors should always be run through an on-line UPS(uninterrupted power supply). This permits the surgery to be completed even ifthe lights go off or the power supply fluctuates or even trips (Fig. 1.2).

Power Generators

In India, as with many developing countries, power outage is not uncommon. Itis important when the theatre is planned that one should compensate for this problem.


Though it would be nice to have automatic switch-over power systems where theload is taken temporarily on batteries and then automatically shifted to the generatedsupply, it is a very costly system which is rarely used. Instead small power generatorsare utilized, adequate to run the theatre lamps, general lighting and power theinstruments, including the Phacoemulsifier and support systems. It is importantthat the wiring be so organized that all that needs to be done, at the time of apower failure, is to turn on the switch and start the generator. The load on thegenerator should never exceed 75 percent of its rated output to prevent overloadand tripping. The generators, which are usually run off petrol, kerosene or diesel,all have a few common features. They are all noisy, smelly and temperamental.Hence they need to be placed in a room with good ventilation, and isolated sothat the sound and smell does not reach in the hospital or theatre complex. Theyshould be serviced regularly, and personnel trained to start and run the units.

Scrubbing Facilities

The scrubbing room should be separate and kept outside the theatre. There is aspecific reason for this. When gloves are worn there is always glove powder scatteredaround which is then be circulated in the room leading to contamination. Not onlydoes this choke up the filters of the air-conditioner, but leave a patina of dust allover the sterile surfaces of the room.

Personnel in the Theatre

The ideal theatre room composition should be a scrub nurse, who surgically assiststhe surgeon, and a circulating nurse, who remains unsterile. In my theatre, whereI like to have a turnover of around 12 to 15 cases per day, preferably in a three-hour period, I find it best to use two separate teams. The scrub nurse who surgicallyassists me in the surgery will, after the case is finished, wash the instruments, placethem into the sterilizing box and then put it herself into the autoclave. The scrubnurse then washes up again, dons a fresh gown and gloves and commences preparingfor the next case preparing the table and opening up the disposables which arehanded to her by the circulating nurse. The unsterile circulating nurse will openthe presterile disposables, remove the instruments from the sterilizer, and handthem across to the scrub nurse. The second scrub nurse, who has been assistingme with the second cases, finishes, moves out, and the totally prepared first scrubnurse is ready to commence the next case.

This technique has a big advantage that the scrub nurse knows all about theinstruments, where they are placed and their functional status. In addition it makesfor far faster and more efficient application.

Theatre Autoclave

The autoclave should be a rapid action unit with flash sterilizing ability. A numberof sterilizing systems are now available. Statim is a common one in usage (I use


the Statim Cassette Autoclave, which has an 8-minute cycle, just perfect) and haspreset operative timing levels, has adequate safety fail-safe built-in, and even hasa small printout which confirms that the autoclaving cycle was complete and effective.The cassette system makes it very simple to insert and remove the instruments.Another good system is the Totawer and the Korean system which work in essentiallyidentical manner. It is important to have a proper place to store the autoclavedinstruments and theatre linen. The corridors and wall nooks are not for this purpose.It has to be in a well-ventilated room, far away from any traffic so that sterilityis not compromised.

The Operating Table

The operating table has, as its primary requirement rock-solid stability even underdeflecting forces, like inadvertent pressure at the head end, or accidental tail endpressure or lateral pressure. The standard operating table with the rotating axisin the middle is not suitable for ophthalmic surgery as the slightest pressure ateither the head end of the table or the tail end of the table causes the entire platformto rock. When an operating microscope is being used, zero movement is permissiblewith any level of safety and efficiency. A very steady table is mandatory.

Some of the operating tables are exceptional, like the Marquette system whichis, however extremely costly. Alternately, more economical systems like the EyeTechtable seem to work equally well and are sufficiently rigid for ophthalmic use.

The table should be motorized permitting free movement both up and downin fine increments so that it could be fine tuned with the surgeon and the microscopein position. There should be the ability to tilt the head end of the patient a littleup or down to compensate for those with a larger anterior/posterior diameter ofthe head, or when little children are being operated. It should wide enough toaccommodate the patient, but narrow at the head end so that it does not impedethe surgeon especially when temporal; surgery is being undertaken. It is also importantthat there should be adequate place under the table for the surgeons feet, the footpedal console of the phacoemulsification unit, as well as for the foot pedal consoleof the operating microscope.

Foot-mounted electrical controllers for an operating table should be avoided asthe irrigating fluid, be it normal saline, Ringer lactate, or balanced salt solution(BSS) is bound to splash on the floor leading to a short circuit. The operating tableshould also have the ability to take a right sided arm rest where the arm can bepositioned by the anesthesiologist for placing an IV cannula for any intravenousinjection or sedation as may be needed the need for inserting a very uncomfortablearm support under the back of the patient (Fig.1.3).

The mattress of the operating table should be at least 3 inches thick. The primitive1 inch hard, unyielding, uncomfortable theatre mattress should be dispensed offwith. Unlike general and orthopedic surgery where the patient is deeply sedatedor even unconscious, the average ophthalmic patient is wide awake. With the adventof topical anesthesia, with the patient having to lie, totally without moving for


long minutes at an end, the minimum which could be expected is a comfortablerubber mattress. The discerning and concerned surgeon should try sleeping on hisor her own operating table to see its comfort level.

There has always been discussion as to whether wrist support is required. Proponentsof the wrist support system feel that it helps in stabilizing the wrist, and at the sametime permits a little cavity or gully for collection of fluids rather than letting the fluidrundown the face. On the other hand, there are others who feel that it restricts thefreedom of movement of the hand around the face and since usually the foreheadis already being used to support the fingers the presence of a wrist rest is superfluous.It is basically a surgeons choice. I personally feel it interferes more with the surgerythan helps, and though I have used it in many operating theatres, have never felt thatit was really necessary. Personally I feel it restricts the free movement of the phacohandpiece. However, it is an individual choice.

The Surgical Chair

Phacoemulsification requires both hands and both feet to be utilized simultaneously.It stands to reason that the surgical chair is an important piece of surgical equipment.It gives the surgeon stability, supports his back, it gives a comfortable seatingarrangement. It is important to remember that the feet have to be kept on the pedalsfor the full time of the surgery, and the surgical chair must be so designed that it preventsany pressure on his thighs. It is imperative that the chair be very comfortable, forthe surgeon will need to sit on it for long hours every day if he is to complete hissurgical list. Any discomfort, overtime, tends to get magnified, which affects, in thefinal score, the surgical competence.

In the intracapsular days, most surgeons operated without any magnifying aidsexcept for low-powered spectacle magnifiers or head-worn loupes, and operatedstanding.

The advent of extracapsular cataract surgery changed the entire gambit. Thenecessity of visualizing the red glow meant the use of a coaxial operating microscopebecame mandatory. With the use of automated irrigation/aspiration units, both feetneeded to be utilized. Thus the surgeon had no option except to sit and operate.

Ideally the operating chair should have a minimum of five and preferably sevensmoothly moving, nylon castors, to give total stability, with a lock on at least twoof them, to immobilize the chair. The arm rest should be of adjustable height andproperly padded and designed with a slight hollow so that during surgery theresting elbows should not slip off (with, as one may well expect, dire consequences).They should support the elbow, but at the same time, should neither restrict, norinterfere with, the surgeons movement. The chair should also fit easily under theoperating table, with adequate space for the surgeons thighs. The area below thehead rest should not be in contact with the chair or its armrests, neither shouldthe base touch against the operating table. The height of the chair could be eitherelectrically or hydraulically adjusted so that the appropriate height for each individualpatient and the surgeon can be utilized. Finally, the chair must be grounded.


Operating Microscope

The microscope is perhaps the most important single piece of equipment in thetheatre. Without an exceptional microscope, good phacoemulsification is difficult,if not impossible.

The basic requirements are as follows:

Excellent optics with clear vision at the edge of the optics There shouldbe no blooming or distortion of the image and the lenses need to be color corrected.The latest microscopes (Zeiss) have apochromatic optics.

Adequate depth of focus The entire lens should be visible from the front tothe back without refocusing. This is very important since when doing phaco thetraverse of the tip from the front to the back of the lens is almost 4 to 5 mm andit is important that excellent focus be available at all times.

Perfect coaxial optics Are of prime importance if a good red glow is to bevisualized. In modern extracapsular cataract extraction (ECCE) and, even more so,phacoemulsification, the surgeon literally operates against the background of thered glow. A good glow from one edge of the pupil to the other is thus a basicrequirement.

Good X-Y device The advantage is that the position of the microscope can beadjusted during surgery utilizing the foot controls without having to manually pusha heavy microscope around. A good X-Y device also compensates for the little headmovement which is to be expected during surgery.

Automated zoom magnification It is not absolutely essential but is extremelyuseful as one can zoom in for a difficult situation ( doing rhexis in a hypermaturecataract, or to see the edges of the capsule while doing posterior rhexis) and thenzoom out with a reduced magnification for more effective surgery.

Easily movable without damaging the unit Should be mounted on movable castorsso that it could be positioned easily and locked in place in the operating theatre.

Proper and stable optics delivery The arm connecting the microscope head tothe supporting pillar should have adequate movement but at the same time shouldpossess rock-solid stability. It should be possible to position the microscope headeasily and then lock the arms.

Tilt optics Not mandatory but makes a great deal of difference in comfort. Thehorizontal to vertical tilt arrangement (range of 90 degrees) is in the opinion ofthe author a really useful device as it makes the difference between operatingcomfortably and struggling and operating. It is particularly useful when operatingon patients who cannot lie flat and who have to be literally operated in a 45-degreeposition. One can position the microscope to be parallel to the plane of the headand then simply tilt the optics to operate comfortably.


Fig. 1.1: Layout of operation theatre with phaco on right

Fig. 1.2: Showing set-up with video, VCR, cardiac monitor, oxygensaturation monitor and cautery on right side of surgery

Preoperative Microscope Positioning

It is imperative that the microscope be positioned accurately at the time of commencingsurgery. Ideally the microscope should be on the right side of the patient, the sameside at which the phacoemulsification unit is kept. The left side is reserved for


Fig. 1.3: Taken from the foot end of the patient. Anesthetist on the surgeonsright side and instrument table on the surgeons left side

Fig. 1.4: Showing the double tubing Surge Suppression Systemattached to the author s Alcon Legacy

permitting the patient to be shifted from the gurney or trolley to the table andthe subsequent removal after surgery. The ideal place for keeping the instrumenttrolley is at patients left. The surgical assistant stands on the same side. The operatingmicroscope camera should have its monitor placed at the surgeons right, set slightly


behind the surgeon so that the scrub nurse and the anesthetist can both followthe progress of the surgery, at the same time it will not distract the surgeon.

An X-Y attachment is a very useful adjunct as it allows the stabilization of theoptical axis to the patients eye during surgery without unnecessary coarse movementsof the optical head. The X-Y device should be placed at its zero position priorcommencing the surgery.

Most microscopes have removable autoclavable plastic, metal or silicone caps for themicroscope. Alternatively, cloth covers, which can be autoclaved, can be utilized.

It is important that all the arrangements and positioning of the microscope bedone prior to commencing the surgery.

The luminosity of the microscope should be kept at the lowest level consistentwith good vision. It is important to remember that the so-called cold fibreopticlight is not really cold but simply not too hot. A good heat shield must be fittedin the microscope especially if the microscope has a filament bulb. Keep the lightintensity low until required.

Prior commencing, the surgeon should place the focus at one-third position, i.e.if the traverse can be visually divided into three parts, it should be fitted in theupper third. This allows the surgeon to have more than adequate range duringsurgery. The surgeon should commence with the microscope focused at the limbuswhere the initial incision will be made. Placing the setting at the upper one-thirdposition of the head traverse, enables the available traverse ( up-down movement)of the microscope to be utilized effectively.

It is also important to adjust the microscope optics to the surgeons ametropiaand his interpupillary distance if the microscope is used in a multi-user environment.

Fig. 1.5: The balancing balls designed byDr Tony Fernandez for softening eye


To enable good coaxiality so as to obtain an excellent red glow the corneal planemust be exactly at right angles to the microscope tube. Be certain to position theeye perfectly prior commencing. Many microscopes come with a small round macularoccluder which can be brought into position after the critical part of the surgeryis over to diminish the quantum of light entering the macula. A simple alternatetechnique is to change the angle of the optics immediately after the cortical aspirationis over and to dim the light. Modern phaco surgery is now so fast that sometimesone wonders whether it is really required, however it is a good practice and shouldbe followed.

Footwear Use in the Theatre

The use of footwear is very much dependent upon the surgeon. I personally preferto use stocking feet rather than using slippers or shoes as I personally feels thatit gives far better control. The use of thin-soled tennis shoes would perhaps workjust as well. The thick-soled Nike and Adidas shoes though excellent in the sportfield are not really useful as the fine control is lost.

Using the X-Y control with stocking feet is a snap as the toes can easily encircle theknob. However, thin-soled shoes do seem to work well. The problem comes about inutilizing the X-Y control on the microscope. Stockinged feet are able to comfortably goaround the tip of the X-Y knob permitting exquisite control. The important guidelinesto observe are comfort. Be careful not to use loose floppy footwear like rubber slippersor cotton slippers, as they tend to slide over the footswitch area and can, in a criticalmoment, jam the footswitch and precipitate problems.

The Patient in the Operating Theatre

Positioning the Patient in the Theatre

The patients head should be positioned in such a manner that the iris plane isparallel to the floor and perpendicular to the coaxial light of the microscope. Incase the patients eyebrow is pronounced or the nose is pronounced, both of whichwould interfere with the surgery, one can easily shift to a full temporal approach.I personally prefer to enter at the 10 oclock position in the right eye and the samein the left eye. The only time I change positions to a full temporal approach iswhen space is inadequate for a proper exposure.

It is always very tempting, after scrubbing, to enter the operating room andwear the gloves from the instrument trolley, next to the patient. It is importantto don the rubber gloves prior to entering the theatre, and as far away from theinstruments trolley as possible. Whenever gloves are snapped on, talcum/glovepowder, which is on the gloves, tends to be liberated and then falls as a fine patinaall over the instruments and the eye. Prior to commencing surgery the surgeonshould wipe his or her hands with a sterile dry towel, after putting on the glovesso as to remove the excess gloves powder. Washing is also acceptable but mustthen be in copious distilled water as otherwise it simply cakes the gloves, makingmatters worse. The dry towel scrub is the best to remove excess glove powder.


Preparation of the Eye

The area around the eye and the eye itself are washed with 10 ml of 50 percentdiluted Betadine 5 percent ( povidone-iodine) solution. A cotton bud soaked infull strength Betadine solution is swept along the lashes to make sure that theyare well cleaned. Subsequently the eye is flushed out with distilled water or withRinger lactate to remove all the impurities. There is never any need to cut lashes.

Draping the Eye

The area around the eye is dried thoroughly with a sterile towel. A sterile self-adhesiveplastic drape, either individually, or as a part of a complete drape, must now be placedover the eye. The method of placement is fairly simple. The eyelids are kept widelyopen either by the surgeons left hand or kept open by the surgical assistant usingcotton buds. The sterile drape is positioned over the opened eye, the tip of the indexfinger is allowed to press the drape in between the opened area, gradually lettingthe drape stick onto the lashes and then onto the area around the eye.

Using a blunt-tipped scissors, the plastic drape is tented and then incised downthe middle being careful that the cornea is not accidentally touched. A soft wirespeculum or a self-retaining speculum is then inserted in such a manner that theincised drape turns over the lashes, and then passes under the lids, held in placeby the speculum, isolating them from the sterile field. Another big advantage ofdraping is that at no time is there any accidental touch at the time of insertionof the phacoemulsification probe or the implant in the eye.

Following the application of the drapes, a second cloth drape can be put overthe site. It has three functions: (i) it acts as an additional sterile barrier, (ii) cutsdown on reflections, and (iii) acts as an absorbent media.

Use of Lid Stitches

In the days of intracapsular and later extracapsular cataract surgery, the use oflid sutures or superior rectus sutures was almost a routine. In the phaco era, lidstitches are used extremely rarely and are quite unnecessary. The only time anysutures are used is a superior rectus suture placed if the surgeon requires moreexposure as when he or she wishes to do a combined glaucoma and cataract procedure.By eliminating the use of a superior rectus stitch, postoperative ptosis incidenceis markedly reduced, it is infinitely less traumatic, eliminates the hematomas, whichoccasionally accompanied the placing of the stitch, and reduces postoperativeinflammation. Since more often than not, topical anesthesia is the technique of choice,the eye is kept stable enough by the patient and the use of the superior rectusstitch is thus redundant.

Suction Facilities

To maintain a dry field during surgery is important. It is very difficult to operatewith a pool of liquid reflecting back the microscope light. Rather than repeatedly


swabbing the area dry, which leads to conjunctival irritation and interferes withthe surgeon, the best is to keep a small suction available. A good option is theuse of self-retaining speculum with aspiration ports attached to a small dental suctionwhich gives suction in the range of 5 to 7 mm Hg. An alternate method is to utilizea drainage device like a sterile plastic bag which can be attached on to the sideof the eye to hold the excess fluid as it drains out, or to use an absorbent wickdrape which permits easy leakage. Which ever device is used, it is important tokeep the floor dry. Dripping irrigating solution can be a source of great irritationto the surgeon when it falls on his or her feet, or wets his or her clothes. In additionthe dripping liquids tends to cause the phaco foot switch to become slippery andmay even jam in time thanks to the dried salt crusts. In addition, the saline iselectrically conductive and is thus an electrical hazard.

FURTHER READING1. Mehta KR, Sathe SM, Karyekar SD: Computer Terminal Usage and Eye Fatigue, Xth Congress APAO.

Soc Proc 2:946-48, 1985.2. Mehta KR: Phacoemulsification cataract extraction with foldable IOLS-First 50 cases. All India Ophthl

Soc Proc 56-60, 1989.3. Mehta KR: Progressive corneal endothelial decompensationextended wear contact lenses with aphakia.

All India Ophthl Soc Proc 109-14, 1989.4. Mehta KR: Endocapsular phacoemulsification and posterior chamber IOL implantation. All India Ophthl

Soc Proc 217-20, 1989.5. Mehta KR: Post-cataract astigmatism: A comparison between phacoemulsification and ECCE procedure:

cataract with and without intra-ocular implantation. All India Ophthl Soc Proc 226-29, 1989.6. Mehta KR: Posterior capsular capsulorrhexis with shallow core vitrectomy following implantation in

paediatric cataracts. All India Ophthl Soc Proc 207-10, 1995.7. Mehta KR: The loop tri suction nonphaco technique of small incision cataract surgery. All India Ophthl

Soc Proc 210-12, 1995.8. Mehta KR: The clear corneal phacoemulsification with injectable silicone lenses. All India Ophthl Soc

Proc 218-22, 1995.9. Mehta KR: An Advanced but simple keratometer for control of postoperative astigmatism. All India

Ophthl Soc Proc 122-23, 1990.10. Mehta KR: Posterior chamber implantation. All India Ophthl Soc Proc 143-44, 1990.11. Mehta KR: YAG laser damage to intraocular implantsan evaluation. All India Ophthl Soc Proc 147-

50, 1990.12. Mehta KR: Phacoemulsificationis it the true III world answer for eye camps. All India Ophthl Soc

Proc 301-303. 1990.13. Mehta KR: An analysis of causative factor leading to eye strain caused by computer monitor screens.

All India Ophthl Soc Proc 334-36, 1990.14. Mehta KR: Single stitch elliptical funnel incision for cataract surgery. All India Ophthl Soc Proc 253-

54, 1991.15. Mehta KR: Bifocal intraocular implantsa functional evaluation based on 425 cases. All India Ophthl

Soc Proc 271-74, 1991.16. Mehta KR: Phacoemulsification with flexible PC IOLis it really a step forward. All India Ophthl Soc

Proc 287-88, 1991.17. Mehta KR: The new phaco cleave technique for hard cataracts. J Intraocular Implant and Refractive Society,

India 1(1): 74-75, 1996.18. Mehta KR, Sathe SN, Karyekar SD: The new soft intraocular lens implant. Am Intraocular Implant Society

J4(4):200-05, 1978.19. Mehta KR, Sathe SN, Karyekar SD: New soft posterior chamber implant, X Congress of the Asia-

Pacific Academy of Ophthalmology. New Delhi,1985.20. Mehta KR: Clear corneal phaco with injectable silicone IOL proc. All India Ophthl Soc Proc (Mumbai)

1995.


21. Mehta KR: Phaco with flexible IOLis it a step forward. All India Ophthl Soc Proc (Bangalore) 1991.22. Mehta KR: The tripod posterior chamber flexible acrylic implant the answer to better stability. APIIA

Conference, 1997.23. Mehta KR: Intralenticular hubbing technique for simple eye camp phacoemulsificationa simple

technique. APIIA Conference, 1997.24. Mehta KR: Newer techniques for eye camp safe phaco techniques. APIIA Conference, 1997.25. Mehta KR: Intralenticular hubbing phaco technique for safe phaco. Proc of SAARC Conference, Nepal,

1994.26. Mehta KR: The New Multiport Phaco Tip for Safer, More Effective Phacoemulsification, with Virtually

Zero Capsular Damage. Proc of SAARC Conference, Nepal, 1994.

The Phacoemulsifier

Mahipal S Sachdev

2INTRODUCTION

It is very important than a thoroughknowledge of the phacoemulsificationmachine is available to the operating surgeon.There are many machines available in themarket, each with their own characteristics.However once the basics of the machine areunderstood, it becomes simple to analyzethem, and having done so, understand howexactly they work. All machines fall into twobasic categories, those utilizing a peristalticpump and those using a Venturi pump. Itis critical that every surgeon learns about themachine parameters and their individualeffects, how they interrelate and in total howthey affect the environment in which thesurgery is performed.

The Machine: Basic Features

The phacoemulsification machine (Fig. 2.1) isessentially a system which generatesultrasound energy transmitted to the tip ofthe handpiece. The machine console onlygenerates the electrical energy. The conversion

Fig. 2.1: The Laser PhacoemulsifierMachine (Alcon Legacy)


of electrical energy into ultrasound is at the handpiece level. The body of the machinethus basically has controls which modulate every key requirements, be it diathermy,irrigation-aspiration control, ultrasound energy stability, or even the height of theirrigation bottle, etc. The fine-tuning is done by the foot switch which gives thesurgeon more flexibility.

Every phacoemulsifier has five basic functions; diathermy, irrigation, irrigation-aspiration, ultrasonic fragmentation and vitrectomy. Each of these functions hasa handpiece to match them.

Irrigation Handpiece

The irrigation handpiece is used when only irrigation is required. It is connectedto an irrigating cystitome for anterior capsulotomy, or to an irrigating loop forhydrodissection. Many machines have the ability to preset controls so that whenonly irrigation is required, the foot switch functions purely as an on-off mechanism.

Irrigation-Aspiration (I-A) Handpiece

The infusion liquid is sent to the anterior chamber through the connected tubes.The basic function of the I-A handpiece is to aspirate liquid and cortical materialthrough the aspiration port, at the same time infusing chamber-maintaining liquidinto the anterior chamber. Essentially the irrigation-aspiration (I-A) handpiece, hasa either single piece metal (stainless steel or titanium) irrigation-aspiration sleeveor has an aspiration sleeve with a silicone sleeve that fits snuggly around the aspiratingtip.

The I-A tip differs from the phaco tip in being smooth and rounded with asingle aspiration port on the side of the tip and not at the end. The sleeve maybe turned to orient the irrigation port in any direction. The irrigation ports in thesilicone sleeve should be kept perpendicular to the metallic aspiration port as thishelps direct the infusion fluid along the iris plane. This reduces iris flutter duringthe surgery.

Typically the I-A handpiece has a rounded tip with the aspirating port at oneside usually 0.75 mm to 1.5 mm away from the tip. The opening can be in a diameterof 0.2, 0.3, 0.4, or 0.5 mm. The overall diameter of the I-A handpiece usually variesfrom 2.5 to 3.0 mm depending on whether the aspiration sleeve is metal, or ofsilicone. The angulations of the I-A handpiece can be straight, 45 bent, or has a90 bend. Most surgeons prefer to utilize the curved I-A tip. Recently Alcon inits Legacy phaco machine has taken out a tip which can be varied as desired termeda steerable tip.

The commonly used I-A port is a 0.3 nun port. It has the safety feature thatit will aspirate the cortex and not the capsule. It is however wise to keep on onestable a 0.5 port so that at times when you wish to aspirate larger particles it isavailable. The larger port is also useful when doing a direct aspiration, as is oftendone in a congenital cataract.

Irrigation/aspiration handpieces corne with metal or silicone sleeves, each havingtheir own advantages.

THE PHACOEMULSIFIER 17

Metal Sleeves

Metal sleeves allow a more regular inflow since they neither are compressed bythe incision edges nor are they compressed if the tip is moved in a tunnel obliquelywhen oar-locking can obstruct the flow. Having smoother edges they are easierto introduce into the phaco tunnel. They also do not snag on the edges of theiris. Naturally being metal, they last much longer (Fig. 2.2).

Fig. 2.2: Irrigation/aspiration metal sleeved handpiece curved, and 90 degrees bent

Silicone Sleeves

Silicone sleeves have greater flexibility and by molding themselves to the walls ofthe tunnel (basically, once a tunnel is opened, it is no longer a slit but ellipticalin shape) give a better fit, thus diminishing the leakage from the chamber. Thisis important especially if the eye pressure is a bit high, chamber is shallow, orin children (Fig. 2.3).

Fig. 2.3: Silicone-sleeved bent for irrigation/aspiration bent

The Diathermy Handpiece

In diathermy handpiece is a very essential adjunct and is ideal when a blood-freefield is required typically in preparation of squared or smile (chexron) scleral orsemiscleral incision.


Diathermy handpieces can be coaxial (Erasertm) or of the forceps type. The coaxialtype is excellent in preparing and having a bloodless scleral area. The forceps onthe other hand can also be used for sealing the edges of the conjunctiva together(coaptation) at the end of the surgery.

It is essential that the minimum quantum of diathermy be utilized. In most modernmachines the control of the quantum of diathermy is linear, i.e. it is controlledby depressing the foot pedal. The maximum and minimum values can be preseton the console.

Anterior Vitrectomy Handpiece

The unit can be either of the guillotine type or of the rotating type with a triangulartip. In the earlier days most machines had the rotating vitrectomy tip, but it wassoon recognized that the moment the unit got a little older it tended to entrapand tug on the vitreous and hence the guillotine vitrector has now become a standardin most machines.

For anterior vitrectomy, the tip usually comes with a perfusion sleeve whichcan be removed if so desired. On the console, the essential values of flow rate,cut rate and vacuum can be set to suit individual requirements.

Ultrasonic Handpiece

Bimanual

It has become customary for many surgeons to use separate handpieces for irrigationand aspiration. This helps immensely in cortical removal (Fig. 2.4).

Fig. 2.4: Bimanual hand pieces, separate for irrigation/aspiration

Phacoemulsification of a lens nucleus depends upon ultrasonic power which isthe function of the acoustic vibrator that has been incorporated into the ultrasonichandpiece. Attached to this vibrator is a hollow titanium needle or the phaco tip.The acoustic energy produced along the ultrasonic handpiece is then transmittedonto the phaco tip (Fig. 2.5).


Fig. 2.5: Phacoemulsification handpiece with four crystals (Alcon Legacy)

The acoustic vibrator is of two types: magnetostrictive or piezoelectric device.The acoustic vibrator converts electrical energy into mechanical energy under theinfluence of an electrical signal. The acoustic vibrator oscillates longitudinally ata frequency between 30,000 and 60,000 Hz. This imparts a linear motion to theultrasonic tip. The stroke amplitude of the linear movement is 3.1000 of an inchand the acceleration 80,000 to 2,40,000 G.

Magnetostrictive Handpiece

Magnetostrictive handpiece was the first in use, and has now been phased out.It uses an electric current to induce a magnetic field which results in the linearmovements of the ultrasonic tip. The electromagnetic field is generated by a coilof wires wrapped around the handpiece.

Advantages and Disadvantages of Magnetostrictive Handpiece

Can be autoclaved repeatedly with no risk to the handpiece Much sturdier. Does not break if dropped Can be repaired easily The handpiece is larger (almost the width of the base of a billiard cue) It is much heavier Needs to be water-cooled The greatest problem is that power delivery is inadequate and often at peak

powers tends to be erratic, more so as the handpiece gets older.

Piezoelectric Handpiece

Piezoelectric handpiece uses electric energy to reorient the piezoelectric crystal whichin turn is translated into linear movement. The piezoelectric transducer requiresa direct electrical contact to be made with the crystal.


Advantages and Disadvantages of Piezoelectric Handpiece

Has a more efficient power delivery. With the use of multiple crystals the fullrange of delivery can be made very smooth even at very small increments.

It is air-cooled Is very much lighter, almost featherweight as compared to the magnetostrictive

handpieces It is however very fragile and can break on being dropped Costly to repair. Some handpieces may need to be calibrated every 1500 phaco

procedures for optimal output.

Phaco Tip

The phaco tip can have various bevel anglesranging from 0 to 60 and comes in variousshapes and sizes. The phaco tip is made oftitanium and is hollow with the distal openingfunctioning as the aspiration port. The acousticenergy produced along the ultrasonic handpieceis then transmitted onto the phaco tip.

The angle of the tips are for basically tworeasons: a flat tip, like the 0 and 15 are excellentfor holding but very poor for cutting; on the otherhand to make a trench in a hard cataract the60 tip is ideal, but because of its large surfacearea of the oblique opening, its holding poweris poor.

Tips may also be of various types, flared atthe end (Cobra tip) or with the tip bent (Mackooltip) or with small ports, termed ABS port (Fig.2.6).

Entering into the anterior chamber is easy withthe 60 tip and progressively harder with a 15or a 0 tip.

The commonly used tips are 30 and 45 phaco tips.

Analyzing the Tips

0 Tip Basically a flat, square cut tip with minimum cutting power but excellentholding capacity. Ideal for phaco chop techniques.

15 Tip Less cutting and more holding power. Suitable for improving follow ability.30 Tip Balanced cutting and holding power. Suitable in most of the phaco

procedures.45 Tip Sharp cutting with good cutting ability and less holding power.60 Tip Very sharp cutting edge with minimum holding power. Ideal for grooving

hard cataracts.

Fig. 2.6: Peristaltic pump of AlconLegacy machine


Tuning the Phaco Tip

The phaco tip is screwed into the handpiece directly using a wrench. The handpieceis then tuned so as to synchronize the mechanical movement of each tip with thehandpiece. Autotuning also allows the handpiece to maintain its frequency irrespectiveof change in the density of the medium. A loose or a heavily used needle willnot tune. It is also customary to tune every time a needle is changed. Some ofthe newer machine (Sovereign Allergan) can retune the needle in few seconds.

The irrigation fluid is made to flow through the two side ports on the siliconesleeve. The silicone hub threads the sleeve onto the outer casing of the handpiece.In some instruments (Alcon), an internal rigid sleeve has also been designed toseparate the aspiration and the irrigation fluids. This is also supposed to reducethe bubble formation that is often encountered during the phaco procedure.

Phaco Power Settings

There is no predetermined correct power. Initially the manufacturers recommendedsettings are used. With experience, each surgeon fine-tunes his settings.

Power variables are adjusted intraoperatively depending on Density of nucleus where phaco tip is engaged Amount of tip engaged Linear velocity of the tip during emulsification.

When the power is inadequate, the tip will fail to cut the nucleus, and tendthe push excessively on the nucleus which lead to zonular stress and can be dangerous.

When the power is too much, rather than holding the nucleus it will cause thenucleus to flyaway from the ultrasound tip, termed chatter. Too much power canalso accidentally pierce the nucleus, making a hole in the capsule and leading toa dropped lens, a catastrophe, best avoided.

Thus setting a safe power setting prior commencing is important. A safe standardsetting is as under.

The ultrasound power is set to 50 to 70 percent. If the lens is soft, it is decreasedto about 30 percent and if it is hard, the power is increased to 80 percent or 90percent. Power is reduced if the nucleus chatters. At this stage, the linear ultrasoundmode is changed to pulse mode, which tends to hold the nucleus better againstthe tip and by giving a break between each pulse enables the fragments to corneto the tip easier.

The third-generation machines, having four crystals per handpiece, have far betterfragmentation control and rarely need the power to be turned up above 70 percent.It is best to consult each individual manufacturer regarding their safe recommendedsettings and only after experience is derived on that machine gradually change thevalues to suit ones individual style of phaco.

Ultrasound is inaudible. The buzzing audible sound often mistaken for ultrasound,is simply the harmonic overtones of the handpiece and phaco tip.


Phacoemulsification Terminology

Phaco power Phaco power is the ability of the phaco handpiece to cut or emulsifya cataract. Phaco power is directly related to stroke length, frequency and efficiencyof handpiece.

Stroke length Stroke length is the distance by which the titanium phaco tip movesto and fro. It is the most important factor in deciding the phaco power. The strokelength can be altered by changing the phaco power setting of the machine.

Frequency Frequency is the number of times the tip oscillates and is fixed for aparticular phaco handpiece. It is measured in kHz.

Preset levels Each surgeon sets his level which he does not wish to exceed duringthe surgery, both for minimum levels as well as maximum levels. This is doneso that the safe levels are not exceeded inadvertently during the stress of surgery.

Linear v/s panel In linear control, pressing the foot-pedal leads to gradual rise ofthe parameters from zero to preset maximum with a linear relation to the foot-pedal control. In panel mode, the parameter reaches the preset panel maximumon pressing the foot switch without any linear foot pedal control. Essentially itpanel is simply on or with no variables in between, panel mode is normally utilizedfor diathermy, flow rate or for vitrectomy settings, never for power settings oraspiration settings on phacoemulsification.

Constant v/s pulse phaco power In constant mode, power is delivered continuouslyand it can be linear or panel controlled. Pulse mode allows phaco power to bedelivered at preset intervals which can be varied. The pulse mode gives relativeintervals where there is absence of tIP movement. This improves the flow characteristicsand helps in evacuating small nucleus particles towards the end of the surgery.The pulse mode is also relatively safer for the epinucleus because a more consistentand predictable cutting power will provide greater stability in the posterior chamber.

Maximum phaco power Maximum phaco power is preset by the surgeon. It determinesthe maximum obtainable ultrasonic energy when the foot pedal is fully depressed.

Actual phaco power Actual phaco power in a machine with a linear foot-pedal controlis proportional to foot pedal position and denotes the power actually being deliveredat a given time.

Effective phaco time (EPT) Effective phaco time is the total phaco time at 100 percentphaco power. It can be less than the total foot-pedal time. EPT is very significantas less EPT indicates proportionately less energy delivered to the eye thereby reducingthe side effects of phaco power. When one compares the energy used between differenttypes of procedures, or even between different instruments, one has to comparethe EPT which is a much more accurate index.


How does phacoemulsificatlon work?

There are various steps involved in the actual phacoemulsification process. Mechanical contact of the tip with the lens Acoustical wave transmitted through fluid in front of the tip Cavitation At the cessation of the forward stroke, the tip has imparted forward

momentum to the fluid and the lens particles in front of it. On the tip beingretreated, the fluid cannot follow thereby creating a void in front of the tip.The void is collapsed by the implosion (cavitation) of the tip thereby creatingadditional shock waves.

There is an impact of fluid and lens particles being pushed forward in frontof the tip.Considering the mechanics of phaco it is clear that there is attenuation of energy

on phacoemulsifying within nuclear material. This reduces the deleterious effectson the corneal endothelium. Therefore, posterior chamber phaco helps to maintainthe safety of the procedure by increasing the working distance from the endothelium.Further, if phaco power is used only when the tip is in the nucleus, the safetymargin is significantly enhanced.

The ultrasonic handle has three functions, namely, irrigation, aspiration andfragmentation. These can be operated separately or simultaneously. The dynamicsof irrigation and aspiration are now considered in detail.

Irrigation System

In most phacomachines, irrigation during phacoemulsification is provided by gravityfeed through the space between the titanium phaco tip and the sleeve. The amountof irrigation is determined by the bottle height relative to the patients eye, by thesleeve diameter, and most importantly by the loss of fluid from the eye.Stable anterior chamber dynamics:

Irrigation = aspiration + leakage from the wound.Rigid sleeves may be preferred over flexible sleeves because the irrigation does

not get compromised while manipulating the handpiece in the incision. The heightof the irrigation bottle during phaco is usually placed between 65 cmand 75 cmabove the eye level. The eye should be at the same level above the floor as thepump (cassette) of the phacoemulsifier.

Aspiration System

Aspiration is defined as the evacuation of fluid through a closed system. Two importantconcepts concerning aspiration are flow rate and vacuum level.

Flow rate Flow rate is the quantity of the fluid pulled from the eye per minutethrough the instrument tip and irrigation tubing. Flow rate therefore helps in bringingthe material towards the tip. Flow rate is measured in cc/min and is dependenton the level of vacuum created in the aspiration tubing by the aspiration pump


and surface area of the port of aspirating tip. Flow rate determines the rate ofrise of the aspiration vacuum when the aspiration port is occluded.

Vacuum Vacuum level is the difference in pressure between atmospheric pressureand the pressure inside the aspiration tubing. This is a negative suction pressurethat is created by the pump.

Port vacuum (mm Hg/min) = the vacuum created (mm Hg)

port area (mrn)2

The vacuum level created at the port therefore varies inversely with the diameterof the tip. The vacuum or negative suction force created helps in holding the materialto the tip and its final aspiration.

Aspiration Pumps

Depending on the machine, three kinds of pumps are used to control aspirationand produce the negative suction pressure, i.e. the vacuum (Fig. 2.7). They are Peristaltic pump Venturi pump Diaphragmatic pump.

Fig. 2.7: The peristaltic pump of the opticon P4000 machine

The peristaltic pump is also known as a constant flow pump while the Venturiand the diaphragmatic pumps are of the constant vacuum variety.

Peristaltic Pump

Peristaltic pump (Figs 2.8 and 9) was popularized by the heart-lung machine. Inthese pumps, a pressure differential is created by compression of the aspirationtubing in a rotatory motion. When the rotational speed is low, vacuum developsonly when the aspiration port is occluded. On occlusion, vacuum builds up to preset


value in a stair-stepped pattern. By increasing therotational speed, as in the newer generationmachines, a linear build-up of vacuum occurs evenwithout occlusion of the tip. It can thus be madeto simulate a Venturi or a diaphragmatic pump.

Advantages of a Peristaltic Pump

Vacuum build-up occurs only on occlusion ofthe aspiration port.

There is a large safety margin in this pump asit is slower in building up vacuum

The peristaltic pump is a dedicated anteriorsegment system

The peristaltic system is a more forgiving systemas there is no inadvertent pull on the ocularstructure since vacuum builds up only onocclusion

The fluidics of the peristaltic pump are morecontrolled with little or no deflation of the ante-rior chamber on sudden removal of occlusion

Vacuum level and flow rate may be controlledindependent of each other

Peristaltic pump allows both zero and highvacuum phaco.

Disadvantages of a Petlstaltlc Pump

The vacuum build-up is directly related to the density of occlusion which inturn would depend upon the bevel angle of the titanium tip and the tissue density

The vacuum build-up is in a stair-stepped pattern

Fig. 2.8: Full functiondisplay of the AlconLegacy Machine

Fig. 2.9: Hand-held full functionremote control of Alcon whichcontrols the Alcon Legacy Machine


Because of the stair-stepped pattern of the vacuum build-up, there could be morepulsations in the anterior chamber

True linear aspiration is not seen, however newer pumps do simulate a linearbuild-up of vacuum

One has to mechanically approach the nuclear or cortical matter to first achieveocclusion for vacuum to build up in order to aspirate the tissue. However, therapid rotation mode has significantly improved the followability of the tissue,even in the peristaltic pump.

Venturi Pump

A Venturi pump uses compressed gas to create inverse pressure. Vacuum generatedis related to gas flow which in turn is regulated by a valve (vacuum build-up occurslinearly in a consistent manner from zero to a preset value. The build-up is almostinstantaneous on pressing the foot-pedal. Due to this there is an increased risk ofiris trauma and posterior capsular rents which make these pumps unsafe, particularlyso for beginners.

Advantages of a Venturi Pump

There is a good follow ability of the tissue The vacuum build-up is linear There is a consistent increase in the vacuum from zero to the preset level on

depressing the foot switch Nuclear and cortical material can be attracted towards the probe on depressing

the foot pedal.

Disadvantages of a Venturi Pump

This pump has the least safety margin and is not forgiving to the surgeon The rise time is too fast There is an immediate rise in the vacuum on pressing the foot switch to position

3 without any linear foot pedal control The incidence of iris chaffing and posterior capsular rents have been reported

to be much higher with this pump as compared to the peristaltic pump Venturi pump does not allow either zero to high . vacuum phaco.

Diaphragm Pump

A diaphragm pump uses a flexible membrane within a cassette to generate vacuum.Build up of vacuum is more linear and reaches the preset level even without occlusion.This makes it unsafe. However, lens material can be aspirated without having tomechanically approach it.

Advantages of Diaphragm Pump

There is an improved linearity of vacuum build-up The flow rate and aspiration are faster Tissue can be pulled towards the center as vacuum builds up to preset even

without occlusion


There is a greater control with the diaphragm pump during posterior segmentsurgery.

DIsadvantages of a DIaphragm Pump

This being a faster pump it offers lesser safety margin Foot pedal depression does not have a very good graded control over vacuum

build-up Rise of vacuum depends on the fluid in the chamber Vacuum build-up reaches preset level even without occlusion. This leads to

inadvertent pull on ocular tissue resulting in a higher complication rate A Venturi is not a forgiving pump and has to be handled by newcomers with

caution though in the hands of an expert it can give excellent results.

Physics of Phaco: Certain Aspects

Aspiration pressure It is modified depending on the stage of surgery and is inverselyproportional to the diameter of the aspirating port. The ultrasonic tip has a portdiameter of 1.00 to 1.20 mm with which the maximum vacuum achievable is 70to 100 mm of Hg. However, in new machines (Alcons Legacy, and the AllerganSovereign series, etc.) the vacuum can be raised to 500 mm of Hg in the phacomode. The I-A tip has a diameter of 0.3 mm and the aspiration pressure may beincreased to 500 mm of Hg.

Rise Time and Pump Flow

Rise time Rise time is a measure of how rapidly vacuum builds up once the aspirationport is occluded.

Pump flow Pump flow is a measure of the rotational speed of the peristaltic pumphead (which in turn determines flow rate and aspiration). This changes from machineto machine.

RelationshIp of Illse TIme and Pump Flow

As the pump flow increases, vacuum builds rapidly as the tip is occluded and thereforethe rise time decreases.

Pump flow is usually preset by the surgeon and is measured as a percentage.Normally 100 percent is equal to flow rate of 35 cc/minute. It is an overall measurementof fluid turnover in the eye. Pump flow determines rise time and event time.

Vacuum Settings

Maximum vacuum Determine the maximum obtainable vacuum when the aspirationport is fully occluded. Maximum vacuum is preset by the surgeon and is measuredin mm of Hg. Typical settings are 65 to 75 mm Hg for phaco and 400+ mm Hg


for irrigation aspiration. The speed at which this vacuum is achieved is determinedby the pump flow setting and the bore of the aspirating tube.

Actual vacuum It indicates pressure at the aspirating port at a given time. This dependson the maximum preset pump flow, degree of tip occlusion and position of thefoot pedal when linear control is used.

RelationshIp Between Pump Flow, Irrigation and Aspiration

With an increase in the pump head rotational speed, the pump flow increases. Dueto this, both aspiration rate and irrigation flow also increase.

Relationship between pump flow, rise time and vacuum To reach a preset vacuum, aspump flow increases the rise time decreases, e.g. if pump flow is doubled the risetime gets halved.

Fluidic Balance

Fluidic balance is the balance between inflow of fluid into the eye and the outflowof fluid out of the eye, which helps in maintenance of the IOP.An adequate fluidic balance provides Constant lOP Stable anterior chamber Protects corneal endothelium and posterior capsule.

The amount of irrigation is determined by the bottle height relative to the patientseye, by the sle

The Art of Phacoemulsification

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