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Copyright © 2001 by Thieme Medical Publishers, Inc. This book, including all parts thereof, is legally protectedby copyright. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation,without the publisher’s consent, is illegal and liable to prosecution. This applies in particular to photostatreproduction, copying, mimeographing or duplication of any kind, translating, preparation of microfilms, andelectronic data processing and storage.Important note: Medical knowledge is everchanging. As new research and clinical experience broaden ourknowledge, changes in treatment and drug therapy may be required. The authors and editors of the materialherein have consulted sources believed to be reliable in their efforts to provide information that is completeand in accord with the standards accepted at the time of publication. However, in view of the possibility ofhuman error by the authors, editors, or publisher of the work herein, or changes in medical knowledge, neitherthe authors, editors, publisher, nor any other party who has been involved in the preparation of this work,warrants that the information contained herein is in every respect accurate or complete, and they are notresponsible for any errors or omissions or for the results obtained from use of such information. Readers areencouraged to confirm the information contained herein with other sources. For example, readers are advisedto check the product information sheet included in the package of each drug they plan to administer to becertain that the information contained in this publication is accurate and that changes have not been made in therecommended dose or in the contraindications for administration. This recommendation is of particularimportance in connection with new or infrequently used drugs

Oculoplastic Surgery

The Essentials

William P Chen, M.D., F.A.C.S.

Associate Clinical Professor Department of Ophthalmology UCLA School of Medicine Los Angeles, CA;

Senior Attending Surgeon Ophthalmic Plastic Surgery Service Department of Ophthalmology Harbor-UCLA Medical Center Torrance, CA;

Associate Clinical Professor Department of Ophthalmology University of California Irvine College of Medicine Irvine, CA

2001

Thieme

New York • Stuttgart

Thieme New York

333 Seventh Avenue

New York, NY 10001

Editor: Esther Gumpert

Editorial Assistant: Owen Zurhellen

Developmental Editor: Felicity Edge

Director, Production & Manufacturing: Anne Vinnicombe

Marketing Director: Phyllis Gold

Sales Manager: Ross Lumpkin

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Cover Designer: Kevin Kall

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Printer: Canale

Library of Congress Cataloging-in-Publication Data

Chen, William Pai-Dei

Oculoplastic surgery : the essentials / William P Chen.

p ; cm.

Includes bibliographical references and index.

ISBN 1-58890-027-4 (hardcover : alk paper)

1 Ophthalmic plastic surgery I Title.

[DNLM: 1 Ophthalmologic Surgical Procedures 2 Eyelids surgery 3 Surgery, Plastic WW 168 C518o 2001]

RE87 C466 2001 617.7'1 dc21

2001027297Copyright © 2001 by Thieme Medical Publishers, Inc This book, including all parts thereof, is legally protected

by copyright Any use, exploitation or commercialization outside the narrow limits set by copyright tion, without the publisher’s consent, is illegal and liable to prosecution This applies in particular to photostatreproduction, copying, mimeographing or duplication of any kind, translating, preparation of microfilms, andelectronic data processing and storage

legisla-Important note:Medical knowledge is ever-changing As new research and clinical experience broaden ourknowledge, changes in treatment and drug therapy may be required The authors and editors of the materialherein have consulted sources believed to be reliable in their efforts to provide information that is completeand in accord with the standards accepted at the time of publication However, in view of the possibility ofhuman error by the authors, editors, or publisher of the work herein, or changes in medical knowledge, neitherthe authors, editors, publisher, nor any other party who has been involved in the preparation of this work,warrants that the information contained herein is in every respect accurate or complete, and they are notresponsible for any errors or omissions or for the results obtained from use of such information Readers areencouraged to confirm the information contained herein with other sources For example, readers are advised

to check the product information sheet included in the package of each drug they plan to administer to becertain that the information contained in this publication is accurate and that changes have not been made in therecommended dose or in the contraindications for administration This recommendation is of particularimportance in connection with new or infrequently used drugs

Some of the product names, patents, and registered designs referred to in this book are in fact registered marks or proprietary names even though specific reference to this fact is not always made in the text Therefore,the appearance of a name without designation as proprietary is not to be construed as a representation by thepublisher that it is in the public domain

trade-Printed in the United States of America

5 4 3 2 1

TNY ISBN 1-58890-027-4

GTV ISBN 3-13-127451-4

Contents

1 Ophthalmic Facial Anatomy, Don O Kikkawa and Sunil N Vasani ……… 1

2 Fundamentals of Oculoplastic Surgery, Dipak N Parmar and Geoffrey E Rose ……… 21

3 Entropion, Jan W Kronish ……… 41

4 Ectropion, David T Tse and Ann G Neff ……… 55

5 Trichiasis, Jeffrey A Nerad and Annie Chang ……… 67

6 Ptosis Management: A Practical Approach, Steven Dresner ……… 75

7 Ptosis: Levator Muscle Surgery and Frontalis Suspension, Philip L Custer ……… 89

8 Facial Nerve Paralysis, Steven Dresner ……… 101

9 Essential Blepharospasm, John McCann, Stanley Saulny, Robert A Goldberg, and Richard L Anderson 111 10 Upper Blepharoplasty and Eyebrow Surgery, Clinton D McCord ……… 125

11 Lower Blepharoplasty and Midface Descent, Norman Shorr and Julian D Perry ……… 147

12 Laser Blepharoplasty, Jemshed A Khan……… 165

13 Laser Skin Resurfacing, Jemshed A Khan ……… 179

14 Laser Facial Resurfacing: Dual Mode, Cary E Feibleman ……… 195

15 Asian Blepharoplasty, William Chen ……… 211

16 Periocular Skin Lesions and Common Eyelid Tumors, Gloria M Bertucci ……… 225

17 Full-Thickness Eyelid Reconstruction, Ralph E Wesley, Kimberly A Klippenstein, Samuel A Gallo, and Brian S Biesman ……… 243

18 Lacrimal System, Marc J Hirschbein and George O Stasior……… 263

19 Thyroid Ophthalmopathy: Eyelid Retraction, J Justin Older ……… 289

20 Thyroid Opthalmopathy: Restrictive Myopathy, Sherwin J Isenberg ……… 297

21 Thyroid Ophthalmopathy: Compressive Optic Neuropathy, Clinton D McCord ……… 305

22 Thyroid Ophthalmopathy: Orbital Decompression for Aesthetic Indications, Mark A Codner ……… 315

23 Enucleation, William Chen ……… 327

24 Evisceration, William Chen ……… 347

25 Exenteration, William Chen……… 355

26 Anophthalmic Socket, Richard A Burgett and William R Nunery ……… 369

27 Orbital Diseases, Joseph A Mauriello Jr ……… 387

28 Orbital Surgery, John Shore……… 419

29 Craniofacial and Neurosurgical Approaches to the Orbit, M Douglas Gossman, Dale M Roberts, and George Raque ……… 451

30 Management of Orbital Injuries, Stuart R Seiff ……… 475

Index ……… 490

Director of Laser Research

Center for Eyelid and Aesthetic Surgery

Clinical Assistant Professor

Department of Plastic Surgery

Emory University

Atlanta, GA

Philip L Custer, M.D.

Professor

Department of Ophthalmology and Visual Sciences

Washington University School of Medicine

St Louis, MO

Steven Dresner, M.D.

Assistant Clinical Professor

Doheny Eye Institute

University of Southern California

Robert A Goldberg, M.D.

Associate Professor of Ophthalmology Department of Ophthalmology Jules Stein Eye Institute University of California Los Angeles, CA

M Douglas Gossman, M.D.

Associate Professor Department of Ophthalmology and Visual Sciences University of Louisville

Louisville, KY

Marc J Hirschbein, M.D.

Clinical Instructor Wilmer Eye Institute Department of Ophthalmology The John Hopkins University Sinai Hospital of Baltimore Baltimore, MD

Sherwin J Isenberg, M.D.

Professor of Ophthalmology and Pediatrics Vice Chairman

Department of Ophthalmology Jules Stein Eye Institute University of California Los Angeles, CA

Jemshed A Khan, M.D.

Clinical Professor Department of Ophthalmology Kansas University School of Medicine Kansas City, KS

Don O Kikkawa, M.D.

Associate Professor Department of Ophthalmology UCSD School of Medicine

La Jolla, CA

Kimberly A Klippenstein, M.D.

Assistant Clinical Professor of Ophthalmology

Vanderbilt Medical Center

Nashville, TN

Jan W Kronish, M.D.

Clinical Associate Professor

Department of Ophthalmology

Bascom Palmer Eye Institute

University of Miami School of Medicine

Delray Eye Associates

George Raque, M.D.

Associate Professor and Vice Chair Department of Neurosurgery University of Louisville Louisville, KY

Dale M Roberts, M.D

Clinical Associate Professor Department of Plastic Surgery University of Louisville Louisville, KY

Geoffrey E Rose, M.D., M.R.C.P., F.R.C.Ophth.

Consultant Ophthalmic Surgeon Orbital and Adnexal Department Moorfields Eye Hospital

London, UK

Stanley Saulny, M.D.

Resident Physician Department of Ophthalmology Jules Stein Eye Institute University of California Los Angeles, CA

Stuart R Seiff, M.D., F.A.C.S.

Professor of Ophthalmology Director of Ophthalmic Plastic and Reconstructive Surgery

University of California San Francisco, and Chief, Department of Ophthalmology San Francisco General Hospital San Francisco, CA

John Shore, M.D.

Texas Oculoplastic Consultants Austin, TX

Norman Shorr, M.D., F.A.C.S.

Clinical Professor of Ophthalmology, Director, Fellowship in Orbital Facial Plastic Surgery Jules Stein Eye Institute

University of California at Los Angeles Los Angeles, CA

George O Stasior, M.D., F.A.C.S.

La Jolla, CA

Ralph E Wesley, M.D.

Clinical Professor of Ophthalmology Vanderbilt University Medical College Nashville, TN, and

Clinical Professor of Ophthalmology University of Tennessee Health Sciences Center Memphis, TN

When I was approached three years ago regarding the feasibility of a book project on theessentials of oculoplastic surgery, my thoughts were that there should be a better way topresent the modern concepts of this field in a succinct fashion There are a few excellentoculoplastic surgery books on the market, but the majority of them still present the ideaswith a lengthy and often traditional approach My aim for this book was to solicit the bestgroup of authors who are excellent clinicians as well as teachers in the academic field,and ask them to write about a special topic in their field of expertise

To achieve this ambitious goal, I planned to design and orchestrate the flow of thecontent so that it would be highly readable and clinically practical, supplemented withclear illustrations as well as line drawings The illustrations would include color images,black and white photos, digital images, line drawings, and algorithms We would add

“Pearls”, “Pitfalls”, and “Recommendations” to the text, as well as summaries of clinicalthought processes in the form of decision trees, or “Clinical Pathways” The bibliography

of each chapter would be relevant and not encyclopedic All this would make each vidual chapter and its content informative and practical; the book would serve as an excel-lent teaching textbook, as well as provide updates on the most recent concepts ofoculoplastic surgery

indi-The aim was for our target audience to include comprehensive ophthalmologistsand resident physicians-in-training, as well as subspecialty-trained practitioners inter-ested in a succinct update on the field of oculoplastic surgery This latter group wouldinclude head-and-neck surgeons, plastic surgeons, neurosurgeons, dermatologists, andeye-care professionals

In terms of the breadth of topics covered, traditional texts tend to concentrate onreconstructive aspects of oculoplastic surgery Some specialized textbooks concentrateseparately, and perhaps predominantly, on aesthetic surgery, while others concentrate

on orbital diseases and surgery I have elected to cover fundamental aspects of plastic surgery in a thorough fashion in the first nine chapters of this book, (entropion,ectropion, trichiasis, ptosis, facial nerve paralysis, and blepharospasm) With the increas-ing popularity and interest in aesthetic surgery, I have allocated six chapters to upperand lower blepharoplasty, surgery of the eyebrows, the field of laser eyelid surgery andfacial resurfacing, as well as blepharoplasty methods unique for Asian patients There is

oculo-a rich source of informoculo-ation in these choculo-apters unoculo-avoculo-ailoculo-able oculo-anywhere in oculo-a single text source.The second half of the book has three chapters that deal with common eyelid lesions,the entire spectrum of full-thickness eyelid reconstruction, and the important topic of thelacrimal system and disorders There are four chapters that deal with the problems asso-ciated with thyroid ophthalmopathy, including eyelid retraction, post-inflammatoryrestrictive myopathy, and orbital decompression for sight-threatening as well as aestheticindications

The last seven chapters discuss pathology and trauma of the orbit, as well as cal approaches They include treatment of the anophthalmic socket and a comprehensivechapter on orbital diseases, orbital surgery, orbital injuries, and the combined disciplines

surgi-of cranisurgi-ofacial and neurosurgical approaches to the orbit The three chapters on ation, evisceration, and exenteration provide the most up-to-date information on recon-structive techniques and presently available implant materials, as well as information oncomparative costs and motility results In essence, the book provides a concentrated

enucle-x

collection of information available from the three major fields of general oculoplasticsurgery, aesthetic oculoplastic surgery, and orbital diseases and surgery.

I am very pleased to say that we have achieved our goals for this project, drawing onthe expertise of 38 distinguished colleagues in the fields of oculoplastic surgery, orbitalsurgery, plastic surgery, and other disciplines including neurosurgery, dermatology, andpathology Many of the authors are members of the American Society of OphthalmicPlastic and Reconstructive Surgery, most of whom are actively engaged in universityteaching programs, with nine of the contributors serving as Fellowship Preceptors(Mentors) for accredited fellowship programs of the American Society of OphthalmicPlastic and Reconstructive Surgery

I thank all of the contributing authors for making this project possible I would nothave been able to complete this project without the help of every one of them, and for this

I am most grateful On the personal side, I thank my wife Lydia, my children Katherineand Andrew, and my mother Katie for being supportive and tolerant of my efforts

Equally important, I thank the highly professional staff at Thieme Medical ers for making this project possible: Andrea Seils for kindling my interest in the project;

Publish-Brian Scanlan (President, New York) for supervising the project; Owen Zurhellen,Michelle Carini, and Thomas Soper (Editorial Assistants) for their tireless efforts and help-ful suggestions; Esther Gumpert (Consulting Medical Editor) for helping me stay cen-tered; and Anne Vinnicombe (Director of Production and Manufacturing), Felicity Edge(Development Editor), and Chris Gauss for their editorial skills, as well as keeping meinformed at all stages I am grateful to Linda Warren, Director of Medical Illustrationsand Audiovisual Education at Baylor College of Medicine in Houston, Texas, for her artis-tic talents and uncompromising punctuality in completing the often-arduous assignments

I gave her Lastly, I thank the library staff, including Emi Wong, at the Long Beach rial Medical Center of Long Beach, California, for their assistance in all my articleretrievals and research needs over the period I worked on this project

Memo-William P Chen, M.D., F.A.C.S.

I wish to express my gratitude to Dr Sonny McCord for teaching me oculoplastic surgery.

The expanding realm of the plastic and reconstructive

ophthalmic facial surgeon demands an intimate

understanding of eyelid, lacrimal, orbital, and facial

anatomy With improvements in technique and

instru-mentation, traditional surgical boundaries are now

being surpassed Hence, as always, the surgeon of the

21st century must have a strong foundation in clinical

and surgical anatomy to perform successful surgery

OPHTHALMIC FACIALSURFACE

ANATOMY

Facial Dimensions

The face has ideal aesthetic proportions Artists have

long recognized the visually pleasing ratios of the

spe-cific vertical and horizontal facial dimensions The

ideal facial dimensions are five eye widths wide and

eight eye widths high.1The ideal face also has a

slightly oval shape

Overall facial dimensions and proportions are ical in aesthetic and reconstructive surgery The eyes

crit-and corresponding areas of the upper crit-and midface

represent key aesthetic units that must be visualized

in the context of overall facial features

Topography and Cutaneous Landmarks

The eyebrows are a foundation for the eyelids They

typically arch above the supraorbital rim and their

lower border should lie 1 cm above the lateral portion

of the orbital rim, with its highest point directly above

the lateral limbus.2Eyebrow cilia are directed at

dif-ferent angles in the upper and lower eyebrow In the

upper eyebrow, the cilia are directed downward from

the vertical plane and in the lower eyebrow, they aredirected upward from the vertical plane.3Medially,all cilia are directed superiorly Brow incisions should

be planned accordingly to preserve cilia With aging,repeated frontalis muscle contraction creates deephorizontal furrows in the forehead Vertical glabellarfurrows, medial to the eyebrow, result from repeatedcorrugator muscle contraction, while horizontalglabellar furrows result from the procerus

The adult palpebral fissures measure 9 to 11 mmvertically and 28 to 30 mm horizontally Ideally, thetwo medial canthi are separated by one horizontalpalpebral width The upper eyelid is positioned at theupper limbus and may cover 1 to 2 mm of the cornea.The highest point of the upper lid margin is just nasal

to the central pupillary axis (Fig 1–1) The upper lid crease is formed by the terminal interdigitations ofthe levator aponeurosis along the superior tarsal bor-der.4Typically, the eyelid crease measures 10 to 12 mm

eye-in women and 7 to 8 mm eye-in men Asians have a low orill-defined eyelid crease because of the low insertion

of the orbital septum on the levator aponeurosis.5The lower eyelid normally rests at the inferior lim-bus and its lowest point is just lateral to the pupil Thelower eyelid crease is formed from cutaneous inser-tions of the lower eyelid retractors The retractors con-sists of the capsulopalpebral fascia and the inferiortarsal muscle It begins medially 4 to 5 mm below theeyelid margin and slopes inferiorly as it continues lat-erally The malar and nasojugal folds represent thecutaneous insertion of the orbitomalar ligament.6Hor-izontal skin folds (laugh lines) that emanate from thelateral canthal angle result from skin folding due toorbicularis oculi With aging as well as thinning of

Chapter 1

Don O Kikkawa and Sunil N Vasani

Supratarsal sulcus Superior

lid crease

Superior eyelid skinfold

Lateral commissure

Inferior lid crease

Malar fold Nasojugal

fold

Nasolabial fold

Punctum

Medial commissure

Punctum

FIGURE 1–1 Normal eyelid topography.

P EARL The surgeon dissecting in region of the eyebrow fat must pay careful attention to the presence of the supraorbital nerve and vessels 10

dermis, these laugh lines become static and rhytids

develop (“crow’s feet”) The lateral canthal angle is

normally 2 mm higher than the medial canthal angle,

giving the eyelids a slight upward flare

Surface marking of the nasolacrimal duct is seen by aline joining the medial canthal angle of the eye to the

canine tooth (eye tooth) on the same side The upper and

lower puncta are located in each eyelid 5 to 7 mm

lat-eral to the medial canthal angle The lower puncta is

usually located 1 to 2 mm lateral to the upper punctum

The Eyebrow

The eyebrows form a key landmark of the upper

facial continuum The skin of the eyebrows represents

a transition zone between the thinner skin of the

eye-lids and the thicker skin of the forehead and scalp

Evaluation of eyebrow position is critical in the

plan-ning of surgery of the eyelids

The position of the eyebrows represents a dynamicinterplay between elevating and depressing forces The

two forces are the elevators (frontalis) and the

depres-sors (orbicularis oculi, corrugator, and procerus) A

submuscular fat pad exists under the interdigitation of

the frontalis and orbicularis muscles.7Termed the

eye-brow fat pad or retroorbicularis oculi fat pad (ROOF),

it continues into the eyelid as the posterior orbicularis

fascia.8, 9Eyebrow fat can be mistakenly identified asorbital fat and can be debulked in certain patients withprominent eyebrow bulk Submuscular fat in the eye-brow region (ROOF) is continuous with suborbicularisoculi fat (SOOF) of the lower lid

develop-of this process

One of the key surgical landmarks of the eyelids isthe orbital septum The orbital septum defines theanterior extent of the orbit and the posterior extent ofthe eyelids It arises from the arcus marginalis, a whitefibrous line that arises circumferentially along the

P EARL Surgically, the orbital

sep-tum may be identified by a traction test

to feel its firm attachments to the orbital rim.

periosteum of the bony orbital margin In the upper

lid, the orbital septum fuses with the levator

aponeu-rosis11at or up to 10 mm from the superior tarsal

bor-der, and in the lower eyelid it fuses with the lower

eyelid retractors just inferior to the tarsus The

orbito-malar ligament emanates from the arcus marginalis

of the inferior orbital rim, traversing through the

orbicularis oculi to insert into the dermis of the lower

lid.12This cutaneous insertion corresponds to the

malar and nasojugal skinfolds With aging, the

orbit-omalar ligament elongates and the orbital septum

attenuates, allowing orbital fat to move anterior and

sometimes herniate below the inferior orbital rim

plates and reflects onto the bulbar surface of the globe The medial and lateral canthal ligaments anchorthe eyelids horizontally to the orbital rims The medialcanthal ligament inserts on both the anterior and pos-terior lacrimal crests.14The medial canthal ligament isassociated with Horner’s muscle (the deep head of thepretarsal and preseptal orbicularis muscle) with both

of them inserting on the posterior lacrimal crest.Lacrimal excretory pump function is dependent onthe contraction of Horner’s muscle, which draws theeyelids medially and posteriorly The lateral canthalligament inserts on Whitnall’s tubercle

The tarsoligamentous band normally provides thehorizontal tension to keep the eyelids opposed to theglobe Horizontal laxity that occurs with aging leads

to eyelid malposition With globe protrusion fromexophthalmos a compensatory lengthening mayoccur, reducing eyelid retraction.15

The main eyelid protractor is the orbicularis oculimuscle It forms part of the superficial muscu-loaponeurotic system (SMAS) The orbicularis oculi isdivided into three parts: pretarsal, preseptal, andorbital.16The muscle of Riolan is a small portion of thepretarsal orbicularis that corresponds anatomically tothe gray line.17

Failure or incomplete separation

Complex Inductive Interaction

Frontonasal process

Maxillary process

Upper eyelids

Lower eyelids

Normal eyelids

Separation

at 5 months

Ankyloblepharon

FIGURE 1–2 Eyelid development.

The backbone of each eyelid, the tarsus, is composed

of dense fibrous tissue and houses the meibomian

glands The tarsus measures 10 to 12 mm vertically in

the upper lid and close to 4 mm in the lower eyelid.13

Conjunctiva firmly lines the inner aspect of the tarsal

P EARL Medial dehiscence of the

levator can lead to horizontal instability that may create difficulty in adequately elevat-

ing the upper eyelid during ptosis surgery.

Another manifestation is the lateral shifting of

the tarsal plate.

The levator palpebrae superioris (Fig 1–3) is one

of the retractors of the upper eyelid It is tendinous in

its distal 14 to 20 mm and the transition from

muscu-lar to aponeurotic portions occurs at Whitnall’s

liga-ment The aponeurosis inserts onto the anterior tarsal

surface via an elastic fiber attachment,18and

interdig-itates into the orbicularis muscle fibers and dermis,

creating the upper eyelid crease Medially and

later-ally the horns of the levator anchor to periosteum

with the lateral horn of the levator dividing the

lacrimal gland into orbital and palpebral lobes

With advancing age, the levator rarefies and maydisinsert from the tarsal attachments leading to ptosis.19

Müller’s muscle arises from beneath the levatorpalpebrae superioris, 15 mm from the upper tarsalborder It consists of smooth muscle and is firmlyadherent to the conjunctiva Müller’s muscle is inner-vated by the sympathetic nervous system and inserts

on the superior tarsal border It provides the upperlid an additional 2 mm of lift Recent studies haveshown that Müller’s muscle extends laterally betweenthe orbital and palpebral lobes of the lacrimal glandalong with the lateral horn of the levator Hence itmay accentuate the lateral flare of the palpebral fis-sure frequently seen in eyelid retraction associatedwith thyroid eye disease.21

The lower eyelid retractors depress the lower lid in downgaze They consist of the capsulopalpebralfascia and the inferior tarsal muscle.20 The capsu-lopalpebral fascia arises from the inferior rectus andinferior oblique muscles The inferior tarsal muscleconsists of smooth muscle The lower eyelid retrac-tors are commonly incised during the transconjunc-tival surgical approach, but this leads to a relativelylow incidence of postoperative eyelid malposition(Fig 1–4)

eye-Inferior oblique muscle

Superficial galea Deep galea Anterior and posterior deep galea

Sub-brow fat pad (ROOF) Frontalis muscle Preaponeurotic fat Orbital septum Preseptal fat (ROOF) Orbicularis oculi muscle Müller’s muscle Levator aponeurosis Superior tarsus Conjunctiva

Inferior tarsus Inferior tarsal muscle Capsulopalpebral fascia (CPF) Orbital septum Orbital fat Orbicularis muscle Malar fat pad Suborbicularis oculi fat (SOOF)

FIGURE 1–3 Eyebrow and eyelid

anatomy (cross section).

The Midface

The midface extends from an imaginary line betweenthe medial and lateral canthi to the mouth Medially,the maxilla and laterally the zygoma form most of thebony skeleton of the midface Prominent bony land-marks include the infraorbital foramen, which liesseveral millimeters inferior to the inferior orbital rim,and, laterally, the zygomaticofacial foramen

The muscles of the face that contribute to facialexpressions are called the mimetic muscles (Fig 1–5).Most of these muscles originate from the midfacialregion The levator labii superioris alacque nasi mus-cle originates on the frontal part of the maxilla andinserts on the alar cartilage and the upper lip Itdilates the nostril, raises the upper lip, and deepensthe nasolabial fold The levator labii superioris musclearises just superior to the infraorbital foramen andoverlies the infraorbital vessels and nerve to insert inthe upper lip Its main action is to raise the upper lip.The levator anguli oris muscle arises inferior to theinfraorbital foramen and inserts into the angle ofthe mouth It causes the expression of contempt anddeepens the nasolabial fold The zygomaticus majorand minor clinically appear as one complex Theyarise from the zygoma close to the zygomaticomaxil-lary suture and draw the mouth upward and out-ward, for example in smiling

FIGURE 1–4 Clinical photo of transconjunctival dissection

of lower eyelid Note forceps pointing to lower lid retractors.

Frontalis muscle

Supraorbital artery and nerve

Supratrochlear nerve Orbicularis oculi muscle Infraorbital nerve Levator labii superioris Zygomaticus minor muscle Zygomaticus major muscle

FIGURE 1–6 Clinical photo of suborbicularis oculi fat

(SOOF) in left lower lid Suture being passed through SOOF

prior to advancement to orbital rim.

artery The superficial temporal artery lies superficial

to the muscle plane of the temporalis muscle

The internal carotid artery contributes to the eyelidblood supply by the terminal branches of the oph-thalmic, lacrimal, frontal, supraorbital, and nasalarteries The marginal and peripheral arcades of theupper eyelid are formed by anastomosis betweenthe lacrimal and nasal arteries The marginal arcade

is located 2 to 3 mm from the upper eyelid margin,and the peripheral arcade lies along the upper tarsalborder near its attachment to Müller’s muscle Eyelidreconstruction with tarsoconjunctival pedicles andtarsal fracture techniques should avoid interruption

of the arcades if possible The dual arcade in the lowereyelid is much less developed

P EARL The location of the ficial temporal artery in the subcutaneous plane makes this a good landmark during tem- poral artery biopsy.

super-The orbital and facial veins also anastomose in theeyelids and midface The angular, superior oph-thalmic and supraorbital veins all communicatesuperomedially in the orbit and hence can propagatefacial infection into the cavernous sinus

Medially, lymphatic drainage from the eyelids andconjunctiva drains into the submandibular nodesand laterally into the preauricular nodes

The eyelids are innervated by the facial nerve nial nerve VII), the oculomotor nerve (cranial nerveIII), the trigeminal nerve (cranial nerve V), and sym-pathetic nerves from the superior cervical ganglion.Motor innervation of the levator palpebrae superiorisand Müller’s muscle, as well as sensory innervation ofthe eyelids are discussed in the orbital section, below.After exiting the stylomastoid foramen, the facialnerve passes through the parotid gland and dividesinto the following divisions: temporal, zygomatic,buccal, mandibular, and cervical The frontal brancharises from the temporal division and travels withinthe temporoparietal fascia (superficial temporal fas-cia) to innervate the frontalis muscle

(cra-SMAS AND SOOF

Mitz and Peyronie described the SMAS, a distinct

fibro-muscular layer that spreads out in a fan-like fashion over

the face The SMAS functions to transmit and distribute

the facial muscle contractions to the skin The orbicularis

oculi muscle is part of the SMAS and has a distinct bony

attachment, the orbitomalar ligament.6With aging, the

midfacial soft tissues become ptotic, resulting in the

typ-ical biconvex topographic appearance.23

Fat located deep to the orbicularis oculi and rior to the periosteum in the midface has been termed

ante-the SOOF.22Its descent contributes to the formation of

“malar bags.” The SOOF varies in thickness from

medial to lateral, being most prominent in the central

and lateral positions In the midface it engulfs the

mimetic muscles and lies superficial to the periosteum

P EARL With proper dissection in

the SOOF plane, either subperiosteal or preperiosteal, the entire midface can be ele-

vated and mobilized 22, 24 (Fig 1–6).

NERVES, LYMPHATICS,

ANDVASCULATURE

Both internal and external carotid arteries supply the

eyelids and midface The external carotid artery

con-tributes the facial artery, the superficial temporal

artery, and the infraorbital artery The facial artery

courses from below the mandible and runs superiorly

and medially; it terminates as the angular artery in the

medial canthal region The angular artery lies 6 to

8 mm medial to the medial canthus and 5 mm anterior

to the lacrimal sac Lacrimal and anterior orbitotomy

incisions should be planned accordingly to avoid this

P I T F A L L

The frontal branch is one of the most monly injured nerves in surgical dissections ofthe temporal region, particularly during fore-head lifting procedures Any dissection should

com-be accomplished com-beneath the plane of the poroparietal fascia to avoid injury to the nerve

tem-The orbicularis oculi is innervated by temporal,zygomatic, and buccal divisions with extensive over-

lap between them The remainder of the facial

mimetic muscles are innervated by the zygomatic and

buccal divisions

Orbital Shape and Dimensions

The shape of the bony orbit approximates a

four-sided pyramid, which becomes three four-sided more

pos-teriorly, due to the absence of the orbital floor

posteriorly.25In the adult, the medial walls of the orbit

are 25 mm apart and are parallel until they converge

near the orbital apex The anterior end of the medial

wall lies 20 mm in front of the lateral wall The

entrance to the orbit is rectangular, measuring 40 mm

horizontally by 32 mm vertically In adults, the depth

from orbital rim to apex varies from 40 to 45 mm

Orbital volume is roughly 30 cc, but varies with race

and sex

P EARL Safe subperiosteal tion may be accomplished along the lat- eral wall and orbital floor for 25 mm and along the medial wall and orbital roof for 30 mm 26

dissec-Margins

Superior Lateral Medial Inferior

Frontal bone

Superior 1/4th frontal

Frontal bone

Maxilla medially

Superior Lateral Medial Inferior

Frontal bone anteriorly

Zygoma anterior

Anterior maxilla and lacrimal

Anterior maxilla

Supra-orbital notch

Inferior 3/4th zygomatic

+

Lacrimal (posterior lacrimal crest)

Zygomatic laterally

Lesser wing

of sphenoid posteriorly

Greater wing

of sphenoid posterior

Ethmoid lamina papyracea

Antero-lateral zygoma

Union of medial 1/3 and lateral 2/3

Strongest Facial buttress

Maxilla (ant lacrimal crest)

Infra-orbital foramen

1 cm inferior

to margin

ethmoid suture

zygomatic suture

Fronto-Posterior body of sphenoid

Posterior palatine

Sutura notha (lateral aspect

of maxilla)

Upper limit for bony medial wall removal

Mark for superior incision in lateral wall removal

Posterior and anterior ethmoid foramen

Inferior orbital fissure

Branch of infra-orbital artery

Anterior and posterior ethmoidal arteries

Upper limit medial wall removal

Limit for floor removal

May bleed during dacryocystorhinostomy

Walls Orbit

FIGURE 1–7 Orbital walls and margins.

Orbital Margins (Fig 1–7)

The orbital margin is an incomplete circle and forms aquadrilateral spiral due to the presence of the lacrimalsac fossa medially The superior orbital rim is formed

in its entirety by the frontal bone At the junction of themedial one third with the lateral two thirds of the supe-rior rim is the supraorbital notch (in 75% of the popu-lation) or foramen (in 25% of the population) Themedial orbital margin is formed by three bones: thefrontal bone, the posterior lacrimal crest of the lacrimalbone, and the anterior lacrimal crest of the frontalprocess of the maxillary bone The inferior orbital rim isderived from the maxillary bone medially and zygo-matic bone laterally The zygomaticomaxillary suture

P EARL Along the lateral aspect of

the frontal process of the maxilla, a fine groove, the sutura notha, can be found 27 This

groove lodges a branch of the infraorbital artery,

and is important when performing external

dacryocystorhinostomy in that bleeding may be

encountered from this site.

P EARL Blunt trauma to the head can cause indirect traumatic optic neuropathy due to the transmission of force along the orbital roof to the optic canal.

fore-lies at the junction of the medial one third and lateral

two thirds of the inferior orbital rim The infraorbital

foramen is closer to the orbital margin at birth and

grows further away, being 1 cm from the rim in the

adult The upper one fourth of the lateral orbital rim is

formed by the zygomatic process of the frontal bone

and the lower three fourths is formed by the frontal

process of the zygomatic bone Articulation occurs at

the zygomaticofrontal suture, a site where a palpable

step is found in cases of fracture

Medial Orbital Wall

The medial orbital wall is formed by the maxillary,lacrimal, ethmoid, and sphenoid bones The mainlandmarks of the medial wall are the anterior andposterior ethmoidal foramina located in a plane justsuperior to the medial canthal ligament; they are

20 mm and 35 mm posterior to the anterior lacrimalcrest, respectively.27 The frontoethmoidal suturemarks the boundary between the roof and the medialwall and the upper limit for bone removal duringorbital decompression The optic foramen is locatedapproximately 50 mm posterior from the anteriorlacrimal crest

Frontal bone

Palatine bone

Ethmoid bone

Lacrimal bone

Nasolacrimal canal

Maxilla

Orbital plate of maxillary bone

Infraorbital groove

Inferior orbital fissure

Zygomatic bone

Greater sphenoid

wing

Lesser sphenoid wing

FIGURE 1–8 Right adult human

orbit (anterior lateral view).

Orbital Walls

Seven bones take part in the formation of the orbit:

the frontal, sphenoid, lacrimal, ethmoid, maxilla,

zygomatic, and palatine (Fig 1–8) Of these the

sphe-noid bone is present in three of the orbital walls and

contributes some of the most important structures

Roof

The orbital roof is formed by the orbital plate of the

frontal bone and the lesser wing of the sphenoid

bone posteriorly The anterior part of the roof is

3 mm thick anteriorly near the frontal sinus, but it

of 8.3 mm superior to a point 10 mm rior to the medial canthal tendon.28

poste-and the zygoma anterolaterally Along the course of

the orbital floor from posterior to anterior, the

infraorbital nerve becomes intraosseous within

the infraorbital canal and is lined by periorbita

The thinnest area of the orbital floor occurs teromedially to the infraorbital nerve Most blowout

pos-fractures occur here Dissection along the medial

aspect of the floor can disrupt the origin of the inferior

oblique, located just lateral to the nasolacrimal canal

Orbital Apex (Fig 1–10)

Three key orbital apex landmarks—the optic foramen,the superior orbital fissure, and the inferior orbital fis-sure—communicate with the intracranial cavity,pterygopalatine fossa, and paranasal sinuses The superior orbital fissure lies between the greaterand lesser wings of the sphenoid The annulus of Zinndivides the fissure into three parts The trochlear,frontal, and lacrimal nerves, the superior ophthalmicveins, and the recurrent lacrimal artery pass throughthe upper part The superior division of the thirdnerve, the nasociliary nerve, the sympathetic root ofthe ciliary ganglion, the inferior division of thirdnerve, and the abducens nerve are in the middle sec-tion The inferior part has the ophthalmic veins.The inferior orbital fissure is bounded laterally bythe greater wing of the sphenoid and medially by thepalatine and maxillary bones The inferior orbital fis-sure communicates with both the pterygopalatine andinfratemporal fossae Blood from the temporalis fossacan reach the orbit through this communication Themaxillary division of the trigeminal nerve, the infra-orbital artery, the inferior orbital vein, and autonomicbranches from the pterygopalatine ganglion passthrough the inferior orbital fissure

FIGURE 1–9 Clinical photo showing marrow space of greater wing of sphenoid during orbital decompression Lateral orbital rim and wall have been removed.

P EARL The infraorbital artery gives blood supply to the inferior rectus and inferior oblique muscles The surgeon should be aware of these branches during infe- rior orbitotomy 32

The optic foramen, located in the lesser wing of thesphenoid, houses the optic nerve and ophthalmicartery The canal reaches adult size by 3 years of age

Lateral Wall

The lateral orbital wall divides the orbit from the

tem-poralis muscle anteriorly and the middle cranial fossa

posteriorly It is composed of the zygoma and the

greater wing of the sphenoid Landmarks of the

lat-eral orbital wall include Whitnall’s latlat-eral orbital

tubercle, and the zygomaticotemporal and

zygomati-cofacial foramina The posterior boundary of the

lat-eral orbital wall is the superior and inferior orbital

fissures Whitnall’s tubercle is located approximately

3 to 4 mm behind the orbital rim and 11 mm inferior

to the frontozygomatic suture.29It is an insertion site

for the lateral canthal ligament, the deep pretarsal

orbicularis insertion, the lateral horn of the levator

aponeurosis, the check ligament of the lateral rectus

muscle, the superior (Whitnall’s) and inferior

(Lock-wood’s) transverse ligaments, and an expansion of

the superior rectus muscle sheath.30

During lateral orbitotomy, the noid suture is a natural breaking point for removal of

zygomaticosphe-the lateral rim If furzygomaticosphe-ther removal of bone is desired,

deeper dissection within the greater wing of sphenoid

will reveal a marrow space and brisk hemorrhage

The middle cranial fossa has been found to be 12 to

13 mm posterior from the superior osteotomy made in

a lateral orbitotomy.31

P EARL Deep lateral wall removal

can be safely done during orbital pression Dural exposure can occur if the inner

decom-aspect of the greater sphenoidal wing is

removed (Fig 1–9).

P I T F A L L

The internal maxillary artery lies immediatelybehind the posterior wall of the maxillarysinus Orbital floor dissection posterior to theinferior orbital fissure could damage thismajor vessel

The diameter of the canal is approximately 6.5 mm

but can enlarge with pathologic processes The optic

strut separates the optic foramen from the superior

orbital fissure.33 The optic nerve is vulnerable to

injury within the canal.34, 35

Although the medial aspect of the optic canal is marily formed by the sphenoid, in approximately 50%

pri-of cases posterior ethmoid air cells are present.25, 36

This variability should be considered when

perform-ing extracranial optic canal decompression and

pos-terior ethmoidectomy during orbital decompression

The posterior ethmoidal foramen is an important

landmark in the orbital apex The medial optic canal

ring, the opening of the optic canal, is located 6 mm

posterior to the posterior ethmoidal artery.37

Periorbita

The periorbita is a thick fibrous layer that internally

lines the bony orbit Anteriorly, it is continuous with

the periosteum, and forms the arcus marginalis, the

origin of the orbital septum In the orbital apex,

the periorbita lines the superior orbital fissure, the

inferior orbital fissure, and optic canal, and is uous with dura

contin-The periorbita provides a protective boundary for theintraorbital contents from adjacent disease processes,limiting spread of infections and tumors The subperi-orbital space is an excellent surgical plane because ofthe ease with which the periorbita can be dissected fromthe bone with minimal resulting hemorrhage

Orbital Fascia

Studies by Koornneef38, 39have shown that the globeand orbital soft tissues are suspended in a complex,organized connective tissue matrix (Fig 1–11A) Thisnetwork is divided into three parts: Tenon’s capsule(fascia bulbi), the extraocular muscles fascial sheaths(Fig 1–11A, 2), and the extensions and check liga-ments that attach the muscle sheaths to the periorbitaand eyelids (Fig 1–11A, 3)

Inferior orbital fissure

Infraorbital artery

Inferior orbital vein

Optic foramen

Between greater and lesser wings of sphenoid bone

Laterally greater wing of sphenoid

Medially Palatine bone of maxilla

Housed in lesser wing of sphenoid

Upper Middle Inferior

Frontal nerve Vth

Ophthalmic veins

Superior div–IIIrd N Trochlear

nerve IVth

Nasociliary N Vth N Lacrimal

nerve Vth

Sympathetic nerves Recurrent

lacrimal artery

Inferior div–IIIrd N Superior

ophthalmic vein

VIth Abducens N

Branches of pterygopalatine ganglion

Ophthalmic artery

Sympathetic nerves

FIGURE 1–10 Orbital apex.

Fascial Sheaths (Fibroconnective Tissue Septa)

Throughout their entire length, the extraocular

mus-cles are encompassed by a fascial sheath The sheath

attaches to the orbital walls via check ligaments and to

the intraconal fat septa.19Anteriorly, the muscles are

connected to the fascia, particularly at their insertion

onto the globe

P EARL Anterior Tenon’s capsule,

when closed properly, provides the est barrier to extrusion of an orbital implant

strong-following enucleation.

B

A

P EARL This attachment can aid

surgeons in finding a muscle if it is lost during strabismus surgery.

extends to the optic nerve posteriorly and is loosely

attached to the globe Externally it attaches to the

fibrous septa of the orbital fat

Fine radial septa also connect the optic nerve tothe medial, lateral, and inferior rectus muscles.40The

intermuscular septum is formed by the muscle

sheaths prior to their insertion on the globe

Poste-rior to this, no common muscle sheath can be

identi-fied.38

The superior rectus and the levator palpebraesuperioris share an intermuscular fascia.41The supe-

rior ophthalmic vein is also located in this complex

Whitnall’s ligament arises from the fascial sheath of

the levator, just at the transition from the rotic to the muscular portions of the levator42(Fig 1–11B)

aponeu-Lockwood’s ligament arises from the fused fascia

of the inferior rectus and inferior oblique muscles.43It

is a hammock-like suspensory ligament that isstrongest anterior to the inferior oblique muscle, andwill support the globe after floor removal and maxil-lectomy, provided that its medial and lateral attach-ments are intact Orbital fat, however, is essential forits function in globe support.44

P EARL The periorbita and medial orbital strut, a ledge of bone between the maxillary and ethmoidal sinuses, play a large role in vertical globe support 45, 46

ORBITAL SOFT TISSUES

Orbital Fat

Fat fills the space of the orbit not occupied by fascia,the globe, muscles, nerves, vessels, and glands.Orbital fat is more fibrous anteriorly, due to theincreased density of the fibrous framework, and morelobular posteriorly

P I T F A L L

Although it is an excellent surgical landmark,orbital fat can be obstructive in deeper surgi-cal dissection

FIGURE 1–11 (A) Schematic arrangement of orbital fibrous septa (Reprinted with permission from Koornneef38 )

(B)Clinical photo of Whitnall’s ligament , right upper eyelid This is a fibrous band found approximately 15 mm above the superior tarsal border.

Preaponeurotic fat

Trochlea Nasal fat pad

Lacrimal sac

Nasal fat pad Inferior oblique muscle Central

fat pad

Arcuate expansion

of inferior oblique muscle

Temporal fat pad

Lacrimal gland

FIGURE 1–13 Clinical compartments of anterior orbital fat.

Superior orbital fat is divided into two distinctcompartments, the preaponeurotic and the medial fat

pads (Fig 1–12) They are separated by the trochlea

The preaponeurotic fat pad, which is more yellow in

color, extends laterally over the lacrimal gland to the

superior edge of the lateral rectus muscle.47 The

medial fat pad, being firmer and pale white in color, is

associated with the medial palpebral artery and the

infratrochlear nerve Deeper anesthetic placement is

usually required for removal of this fat pad during

blepharoplasty Because of their close relationship to

the trochlea, superior oblique palsy and Brown’s

syn-drome have been reported from injury during upper

eyelid blepharoplasty.48

The inferior orbital fat can be divided into threecompartments.49The medial fat pad is separated from

the central fat by the inferior oblique muscle The

FIGURE 1–12 Clinical photo showing preaponeurotic

fat pad, right upper eyelid.

medial and central fat pads are continuous, with thevalley of the inferior oblique dividing the two Thecentral fat is separated from lateral fat pad by thearcuate expansion of the inferior oblique muscle,which courses inferotemporally

P EARL The inferior orbital fat is an excellent surgical landmark during tran- sconjunctival inferior orbitotomy (Fig 1–13).

The dissection plane can occur either preseptally,remaining anterior to the orbital fat, or postseptally

to approach the inferior orbital rim

Vasculature

The ophthalmic artery, the first branch of the internalcarotid artery, provides the major blood supply to theorbit The external carotid artery also contributes viathe middle meningeal and maxillary arteries

The main venous drainage system of the orbitoccurs via the superior and inferior ophthalmic veins,which lie within the connective tissue septa The largersuperior ophthalmic vein (SOV) arises superomediallynear the superior oblique tendon with contributionsfrom the angular, supraorbital, and supratrochlearveins It travels near the medial aspect of the superiorrectus muscle, then enters the muscle cone andreceives branches from ciliary and superior vortexveins The SOV then travels beneath the superior rec-tus muscle along the lateral border of the muscle toenter the superior orbital fissure and subsequently thecavernous sinus The SOV hammock is a connective

The oculomotor nerve (CN III) divides into rior and inferior divisions within the cavernous sinusprior to entering the orbit The two divisions enterthe orbit through the superior orbital fissure, sepa-rated by the nasociliary nerve The superior divisionsupplies the superior rectus and the levator The infe-rior division enters the intraconal space beneath theoptic nerve and supplies the medial rectus, inferiorrectus, and inferior oblique The branch to the infe-rior oblique carries pupillomotor fibers to the ciliaryganglion.

supe-FIGURE 1–14 Computed tomography (CT) scan of

patient with left orbital abscess Note stretching of left optic

nerve with globe tenting.

The trochlear nerve (CN IV) enters the orbit side the annulus of Zinn through the superior orbitalfissure It is unique in four aspects: it is the only motornerve to the extraocular muscles that remains outsidethe muscle cone, it has the longest intracranial course,

out-it arises from the brainstem dorsum, and out-it completelydecussates

The abducens nerve (cranial nerve VI) enters theorbit through the superior orbital fissure withinthe annulus It travels between the optic nerve and thelateral rectus muscle to innervate the muscles throughits inner surface

The ophthalmicAV1B and maxillary AV2B divisions

of the trigeminal nerve supply cutaneous sensoryinnervation to the upper two thirds of the face andthe orbit The ophthalmic division enters the orbitthrough the superior orbital fissure and divides intothe lacrimal, frontal, and nasociliary nerves Thelacrimal nerve courses superotemporally along theupper border of the lateral rectus to supply thelacrimal gland, lateral conjunctiva, and lateral uppereyelid The frontal nerve travels between the perior-bita and the levator and branches into supraorbitaland supratrochlear nerves The supratrochlear nerveinnervates the medial upper eyelid and glabellarregion The supraorbital nerve exits the orbit throughthe supraorbital notch or foramen and supplies theforehead The nasociliary nerve is the only branch toenter the orbit above the optic nerve through theannulus, and travels between the superior obliqueand medial rectus muscles Branches of the nasocil-iary nerve include the posterior and anterior eth-moidal nerves, several long ciliary nerves, a sensoryroot to the ciliary ganglion, and the infratrochlearnerve

tissue structure seen on magnetic resonance imaging

(MRI), which supports the SOV in its course The

ham-mock courses from the lateral rectus toward the

super-omedial orbital wall.50The smaller, more variable,

inferior ophthalmic vein (IOV) forms along the orbital

floor from a plexus with contributions from the

infe-rior extraocular muscles and infeinfe-rior vortex veins The

IOV then courses posteriorly along the inferior rectus

muscle and then empties into either the SOV or

inde-pendently into the cavernous sinus

Although the orbit has been traditionally thought

to be devoid of lymphatics, recent studies in the

mon-key orbit have identified the presence of lymphatics in

the dura of the optic nerve and the lacrimal gland.51

Orbital Nerves

Five of the twelve cranial nerves (CNs) supply the

orbit Along with sympathetic and parasympathetic

contributions, these nerves enter the orbit through the

orbital apex

The optic nerve (CN II) is essentially a neural tractextending from the brain, being covered by meninges,

surrounded by circulating CSF, and containing

neu-roglial cells The nerve has intraocular, intraorbital,

intracanalicular, and intracranial segments The optic

nerve is formed by retinal ganglion cells axons and exits

the globe at the lamina cribrosa This intraocular

seg-ment is 1 mm long and 3 mm in diameter.52The

intra-orbital segment measures 24 mm, 6 mm longer than the

direct length between the sclera and the opening of the

optic foramen This slack allows unrestricted globe

movement and some slack if proptosis should occur

P EARL Globe tenting, a radiologic

sign, is seen with severe proptosis, ing optic nerve tethering on the back of the

caus-globe 53 If the posterior scleral angle is less than

90 degrees, severe tension is present (Fig 1–14).

P I T F A L L

Injury to the nerve has been described inpatients undergoing repair of orbital floorfractures, causing pupillary dilation.54

The maxillary division AV2B enters the gopalatine fossa through the foramen rotundum.

ptery-After branching as the zygomatic, sphenopalatine,

and posterosuperior alveolar nerves, the majority of

the nerve enters the orbit via the infraorbital fissure

as the infraorbital nerve The zygomatic nerve

becomes the zygomaticofacial and

zygomaticotempo-ral nerves The zygomaticofacial nerve exits through

its named foramina to supply the cheek, while the

zygomaticotemporal nerve passes through its named

foramen into the temporalis fossa to innervate the

lat-eral forehead The infraorbital nerve exits the

infraor-bital foramen to supply the lower eyelid, the lateral

aspect of the nose, and the upper lip

Sympathetic nerve supply to the orbit causes lary dilation, Müller’s and inferior tarsal muscle con-

pupil-traction, vasodilation, and hidrosis Sympathetic

nerve fibers begin in the superior cervical ganglion

and enter the cavernous sinus surrounding the

inter-nal carotid artery

Parasympathetic nerves supply the ciliary muscle,pupilloconstictor fibers, lacrimal gland innervation,

and vasodilatory fibers Preganglionic fibers from the

Edinger-Westphal nucleus destined for the orbit

travel with the inferior division of the oculomotor

nerve and, as mentioned previously, course with

the nerve to the inferior oblique They then synapse

in the ciliary ganglion before postganglionic fibers

enter the globe as short posterior ciliary nerves Most

of these fibers (90%) supply the ciliary body and the

remainder innervate the iris sphincter Traditional

thought is that lacrimal gland innervation is supplied

by the nervus intermedius portion of the facial nerve

The ciliary ganglion is located between the lateralrectus and the optic nerve approximately 15 mm pos-

Frontonasal ostium

Inferior turbinate

Middle turbinate

Sphenoid sinus ostium

Ethmoidal ostia

Frontonasal duct Ethmoidal bulla Uncinate process Semilunar hiatus Maxillary sinus ostium Nasolacrimal duct ostium

FIGURE 1–15 Lateral wall of the nose.

terior to the globe Parasympathetic fibers synapse inthe ganglion, while sympathetic and sensory axonspass through Several short ciliary nerves exit the cil-iary ganglion, the majority of which supply the globelateral to the optic nerve

NOSE ANDPARANASALSINUSES

Because of the proximity to the orbit, paranasal sinusdiseases often present with orbital signs Thus, itbehooves the orbital surgeon to be familiar with nasaland sinus anatomy The nasal cavity is divided intotwo parts by the nasal cartilaginous septum and thevomer of the ethmoid bone The turbinates (inferior,middle, superior, and sometime supreme) are located

on the lateral nasal wall, and the space below eachturbinate is named respectively The inferior turbinate

is the largest, whereas the smaller middle and rior turbinates arise from the ethmoid bone The mid-dle turbinate is easily seen on external examination

supe-P EARL The turbinates function to moisturize the inhaled air, filter particu- late matter, and provide resistance during inhalation Due to their importance, attempts should be made to preserve them during naso- lacrimal procedures.

The maxillary sinus is the largest of the sinuses.Due to its predominantly inferior growth, the maxil-lary sinus drains superiorly into the hiatus semilu-naris just posterior to the uncinate process ofthe middle meatus (Fig 1–15) Relationships of the

with the internal carotid artery, the optic nerve, andthe cavernous sinus.

GLOBE ANDEXTRAOCULARMUSCLES

The globe is located slightly superior and lateral to thecenter of the anterior orbit The front surface of theglobe is in the same plane as the superior, medial, andinferior orbital rims but is anterior to the lateral rim by

12 to 18 mm Changes in eye position occur withaging when measured by exophthalmometry, orbitalwidth, and interpupillary distance.58Exophthalmom-etry readings generally increase until age 20 In theelderly, interpupillary distance increases, most likelydue to atrophic changes

All extraocular muscles arise from the orbital apexexcept the inferior oblique The four recti musclesarise from the annulus of Zinn; the levator muscle andsuperior oblique originate superomedially from thelesser wing of the sphenoid; and the inferior obliquearises from the orbital floor anteriorly, just lateral tothe lacrimal sac

LACRIMALSYSTEM(FIG 1–18)

Secretory System

The lacrimal secretory system consists of the lacrimalgland and the accessory lacrimal glands They pro-duce the aqueous component of the tear film Thelacrimal gland is divided into a larger orbital lobe and

a smaller palpebral lobe by the lateral horn of the ator (Fig 1–19)

lev-The orbital lobe molds within the space betweenthe globe and the lateral orbital wall The palpebrallobe resides beneath the levator aponeurosis and isseparated from the conjunctiva by Müller’s muscle.Lacrimal gland prolapse can occur with laxity of theattachments, causing a noticeable bulge in the lateralportion of the upper eyelid

maxillary sinus include the nasolacrimal duct

medi-ally, and the pterygopalatine fossa and maxillary

artery posteriorly Creation of nasal antral window

can injure the nasolacrimal duct

The ethmoid sinuses arise during the fifth month

of gestation and continue to expand until puberty

The ethmoid sinus is the most exhuberant sinus and

it may pneumatize the frontal, sphenoid, palatine,

and lacrimal bones The ethmoids are best

visual-ized as a box that is slightly wider posteriorly

(Figs 1–16 and 1–17) Anterior and middle air cells

drain into the middle meatus, whereas posterior air

cells open into the superior meatus Anterior

eth-moidal air cells can extend anteriorly past the

pos-terior lacrimal crest,25, 55 and may be encountered

during dacryocystorhinostomy

FIGURE 1–16 CT scan (axial view) of ethmoid and

sphe-noid sinuses Note opacification of right anterior ethmoidal

air cells.

FIGURE 1–17 CT scan (coronal view) of ethmoidal and maxillary sinuses Note orbital strut found at the junction

of ethmoid and maxillary sinuses.

The frontal sinus expansion begins at about 6 years

of age and continues until adulthood The frontal

sinus is divided by a midline septum and is a

com-mon site for mucocele development It drains via the

nasofrontal duct.57

The sphenoid sinus is pneumatized to a variabledegree Ethmoidal air cells may pneumatize the sphe-

noid sinus It typically has a midline septum and

drains into the sphenoethmoidal recess The lateral

wall of the sphenoid sinus has a close relationship

P I T F A L L

Ethmoidectomy performed endoscopically orexternally can breach the lamina papyracea ofthe medial orbital wall, placing the medialrectus and optic nerve at potential surgicalrisk.56

Lacrimal System

*M.C.T., Medial Canthal Tendon

Secretory

Main lacrimal gland

Accessory glands

Basic tear secretors

No parasympathetic supply

Divided by lateral horn

of levator

10–12 secretory lobes

Open at superolateral conjuctival fornix

Reflex tear secretion

Both parasympthetic and sympathetic innervations

Krause Wolfring

Orbital lobe

Palpebral lobe

Open superior fornix 40–42 glands

Open upper border of superior tarsus 2–5 glands

Inferior fornix 6–8 glands

Lower border of inferior tarsus 2 glands

Excretory

Lacrimal pump

Upper and lower puncta 1.0–1.5 mm diameter

Pretarsal orbicularis

Horner's muscle

Compress ampullae

Preseptal orbicularis +

Shortens canaliculi

Compress and expand lacrimal sac

Canaliculi Vertical (2 mm)Horizontal (8 mm)

Lacrimal sac (15 mm

x 5 mm)

4–5 mm extension above M.C.T (fundus) of sac

Valve of Hasner

in inferior meatus

Nasolacrimal duct (15 mm

x 3 mm)

Interosseous groove between maxilla and lacrimal bones

*

FIGURE 1–18 The lacrimal system.

Secretory ducts (10 to 12) from the orbital lobe passthrough the palpebral lobe or stay very close to it, to

open into the superotemporal conjunctival fornix

Both sympathetic and parasympathetic fibersinnervate the lacrimal gland The lacrimal gland is

supplied by the lacrimal artery and from a branch of

the infraorbital artery Recent studies show that the

lacrimal artery also supplies the lateral aspect of

Müller’s muscle.59

The accessory lacrimal glands of Krause and fring lack parasympathetic innervation Approxi-

Wol-mately 20 accessory lacrimal glands are present in the

superior conjunctival fornix, and about half that

num-ber are present in the lower eyelid Because they do

not have parasympathetic innervation, the accessory

glands are thought to be basic secretors, with the mainlacrimal gland responsible for reflex tearing.60

Excretory System

Tear flow and excretion is a dynamic process dent on eyelid blinking Tear excretion begins in thepuncta, which measure 0.3 mm in diameter and arenormally in firm opposition to the globe

depen-P EARL Usually not visible on ternal examination, if the puncta can be seen without eyelid eversion, punctal ectropion

ex-is present.

The upper and lower canaliculi measure 2 mm tically and 8 mm horizontally Most of the time, the

ver-canaliculi join to form a common canaliculus, located

within the central portion of the medial canthal

liga-ment (Fig 1–20) The valve of Rosenmüller is a

func-tional valve present at the opening of the common

canaliculus into the lacrimal sac Its function is to

pre-vent reflux, and in the presence of a coexistent

naso-lacrimal duct obstruction it may precipitate the

development of dacryocystitis Recent studies have

found that the canaliculi bend posteriorly behind the

medial canthal ligament, then anteriorly to enter

the sac at an angle of 58 degrees to the lateral wall

of the sac This anatomic configuration may also

contribute to the one-way valve.61

The lacrimal sac is located within the bony lacrimalfossa and is covered by periorbita and surrounding

fascia, making it technically external to the orbit The

sac measures 12 mm vertically, with 4 mm of it being

superior to the medial canthal ligament The

intraosseus nasolacrimal duct measures 12 mm and it

extends an additional several millimeters into the

inferior meatus

Levator aponeurosis

Ductules Palpebral

lobe of lacrimal gland

Valve of Krause

Valve of Hasner Nasolacrimal duct

Inferior canalicus Spiral valve of Hyrtl

Valve of Taillefer Inferior turbinate Lacrimal sac

FIGURE 1–20 Nasolacrimal excretory system.

REFERENCES

The authors wish to acknowledge Alexander Lee,

B.A., for his assistance with reference research

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3. Lemke BN, Stasior OG: Eyebrow incision making Adv

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4. Gavaris P: Editor’s note: The lid crease Adv Ophthalmic

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P EARL Lacrimal sac swelling ondary to infection typically occurs infe- rior to the medial canthal ligament Swelling superior to the medial canthal ligament is a warning sign of a lacrimal sac malignancy.

sec-SUMMARY

Integrated knowledge of the superficial and deep ers of the face, eyelids, orbit, and lacrimal system isessential for the clinical practitioner who deals withaesthetic and reconstructive surgery of the eyelids,orbit, and surrounding adnexa This chapter provides

lay-a blay-asic foundlay-ation of core knowledge in lay-anlay-atomyneeded for oculoplastic surgery

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System New York: Aesculapius, 1976.

Oculoplastic surgery draws upon a wide variety of

techniques and disciplines, but has emerged in recent

years as a distinct subspecialty Although general and

periocular plastic procedures have been described as

early as the 6th or 7th century B.C., contributions from

other disciplines have led to a plethora of oculoplastic

techniques; such specialties including general plastic

and reconstructive surgery, otorhinolaryngology,

neurosurgery, neuroradiology, dermatology, and

radiation oncology.1, 2Many oculoplastic procedures

are now available to treat any distinct surgical entity,

but adherence to the basic principles outlined below

will generally provide a good result with minimal

scarring and excellent aesthetics

EVALUATION

Oculoplastic surgery is largely performed for

func-tional reasons, but aesthetic factors are invariably

involved It is therefore important to evaluate the

patient from a medical, functional, aesthetic, and

psy-chological perspective

An appropriate history and physical examination

is mandatory in all patients, with particular attention

directed toward factors that may cause problems

dur-ing or after surgery Risk factors for intraoperative

hemorrhage should be sought, including

hyperten-sion, liver disease, anticoagulation therapy, and

treat-ment with vitamin E, aspirin, or nonsteroidal

antiinflammatory agents Such medications should be

stopped at least 14 days prior to surgery, although

anticoagulants cannot always be discontinued—as,

for example, in patients with mechanical heart valves;

in these cases anticoagulation should be reduced to a

minimum acceptable level by an internist tively, a rapidly reversible agent, such as intravenousheparin, may be used to maintain anticoagulationduring the perioperative period, before full oral anti-coagulation is resumed Conditions that may causeimmune suppression and predispose to postoperativeinfection should be sought, including diabetes melli-tus, human immunodeficiency virus infection,chemotherapy, or transplant-related immunosup-pression Specific inquiry for previous periocularsurgery, trauma, or radiation should be made, the lat-ter alerting the physician to the possibility of inducedmalignancy A family medical history is important toexclude hereditary disorders, such as malignanthyperthermia and congenital ptosis

Alterna-A problem-oriented general, ophthalmic, andoculoplastic examination should be performed andthis also provides a time to gain rapport with thepatient, a rapport vital to determining the patient’sexpectations for surgery and whether these can berealistically achieved Functional and aesthetic con-siderations are closely linked in oculoplastic surgeryand so it is important to identify the patient who ispsychologically unstable.3, 4Such cases are unsuitablefor aesthetic surgery and require a prompt reevalua-tion of the indications for functional surgery

Most nonorbital oculoplastic surgery is performedunder local anesthesia, with the option of monitoredintravenous sedation, and hence little preoperativeworkup is required from the anesthetic aspect Opticnerve function may be assessed in orbital disease bycolor vision testing, visual field analysis, and possi-bly visual-evoked potentials, whereas lacrimal prob-lems may entail dacryocystography Computed

occurs in an open, untreated wound The sequence ofphysiologic events is similar in both categories,although wound contraction plays a predominantrole in secondary wound healing.

Although wound healing has traditionally beenclassified into four phases, it is important to realizethat this is actually a dynamic process with remodel-ing continuing often for years after the initial injury.9

Inflammatory Phase (4 to 7 Days After Injury)

Immediately following injury, the acute inflammatoryresponse is orchestrated to allow epithelialization ofthe wound Inflammatory mediators and cytokines arereleased, which cause localized vasodilatation andincreased capillary permeability, recruiting acuteinflammatory cells such as granulocytes, macrophages,and lymphocytes to the wound

A fibrin-platelet clot initially bridges a sutured wound Epithelial cells migrate and prolifer-ate from the wound edges downward to the basewithin hours, completely covering the wound within

well-12 to 24 hours Capillary budding provides a work for proliferation of epithelium, which is reorga-nized and aligned during days 10 to 15

frame-Fibroblastic Phase (Week 1 to 4)

Fibroblasts migrate into the wound during the matory phase and produce increasing amounts of col-lagen, followed by collagen lysis after day 17, so that

inflam-by 4 weeks an equilibrium is reached An acellular

“ground substance” produced during this phase isessential for fibroblast proliferation and collagen syn-thesis, being rich in chondroitin sulfate, hyaluronicacid, and other mucopolysaccharides

Maturation Phase (Week 4 to Several Years)

Fibroblasts leave the wound during this phase lowed by alignment and restructuring of collagen

fol-FIGURE 2–1 Photograph demonstrating the use of head lighting to show image depth by shadowing.

over-tomography is invaluable in defining orbital and

adnexal disease, particularly when the expertise of

an orbital radiologist is available, although magnetic

resonance imaging occasionally provides further

information when there is associated optic nerve

pathology

Photography

Photography is essential in the evaluation of any

ocu-loplastic patient, and ideally should be performed at

the first preoperative visit, in the operating theater,

and postoperatively.5Although the medicolegal

ben-efits are obvious, photographs also provide a record

of both functional and aesthetic changes following

treatment, which is particularly useful in patients who

are excessively anxious

It is important to photograph the patient in the mary position of gaze, but further positions may also

pri-be useful—looking up or down, looking left or right,

and lateral views can be taken if required.6The

photo-graphic system used should provide consistent and

correctly exposed images The 35 mm single-lens reflex

camera is ideal for oculoplastic use, particularly in

con-junction with a macrolens, to take well-magnified,

undistorted images The 50 mm macrolens is

practi-cally the lightest with which to work, but requires close

proximity to the subject A better option for the

oper-ating theatre is the 90 mm macrolens, which allows a

greater distance between the photographer and the

operating field Polaroid photography is a useful

alter-native, allowing instant images for discussion with the

patient, but with a compromise in quality

Digital photography is increasingly popular intoday’s environment, with an image resolution that is

continually improving and now comparable to

tradi-tional methods Although this provides an efficient

method of image capture and storage, it also allows

the likely postoperative appearance to be

demon-strated to the patient using image manipulation

P EARL Oculoplastic photographs

are best taken with eccentric illumination from above, to show image relief (Fig 2–1).

WOUNDHEALING

An understanding of cutaneous wound healing is

important for the oculoplastic surgeon and has been

traditionally divided into two categories.7, 8Primary

wound healing, or healing by primary intention,

occurs when wound edges are apposed as they are in

a sutured surgical wound Conversely, secondary

wound healing, or healing by secondary intention,

FIGURE 2–2 Secondary wound healing of a left lower eyelid medial defect following excision of a basal cell

carci-noma (A) Day 1 (B) Month 5 postoperatively.

B A

fibers, thus leading to near maximum wound strength

at 3 months Although this process may continue for a

year or more, overall wound strength never quite

reaches that of uninjured skin

Wound Contraction

Wound contraction plays a prominent role in

sec-ondary wound healing and is often extensive in open

wounds Epithelial migration and proliferation

advances centrally with the release of proteolytic

enzymes along the advancing edge, using the fibrin

clot as a scaffold Myofibroblasts contain contractile

elements and drive the centripetal movement of the

wound edges The rate of wound contraction is

high-est for 2 weeks after injury (resulting in an initial rate

of closure of 0.6 to 0.75 mmday), continuing

there-after for several months at a slower rate Closure of a

contracting wound does not always proceed at the

same rate in all directions and depends on several

fac-tors, including attachments to surrounding tissues

and the shape of the defect

Secondary wound healing is of limited use in loplastic surgery, confined to selected cases of infec-

ocu-tion and burns Its use in periocular reconstrucocu-tion is

controversial, although successful results have been

reported after resection of medial canthal, glabellar,

and eyelid margin cutaneous tumors (Fig 2–2).10, 11

Matrix Metalloproteinases

Matrix metalloproteinases (MMPs) are a family of

zinc-dependent endopeptidases capable of

degrad-ing almost all extracellular matrix components,

including collagen.12They are central to a wide range

of physiologic and pathologic processes and are

intricately involved in the fine balance between

col-lagen synthesis and degradation during wound

heal-ing MMPs are an important determinant of final

wound strength, being regulated by tissue inhibitors

of MMP Inhibition of MMP activity has been shown

to enhance wound strength in rats, suggesting that

in due course MMP modulation may provide apotential means of influencing wound healing andmaturation.13

TECHNIQUES

Anesthesia

The anesthetic options for oculoplastic surgery rangefrom local infiltration to general anesthesia, depend-ing on the patient’s age, level of anxiety, degree ofcooperation, and systemic status.14, 15Most oculoplas-tic procedures can be carried out under infiltrativelocal anesthesia, but the surgeon must be aware ofrare cardiovascular reactions that may necessitateresuscitation

Adjunctive sedation with a benzodiazepine is oftenuseful in anxious patients or those undergoing pro-longed procedures Intravenous sedation, titrated by

an anesthetist, is also useful in supplementing thelocal block, particularly when a deeper level of seda-tion is required or systemic problems preclude the use

of a general anesthetic The level of sedation can ily be lightened to increase the level of patient coop-eration, as may be required during levator musclesurgery A general anesthetic is used in children andfor more extensive procedures such as major recon-structions or orbital surgery

eas-PEARL Levator muscle surgery is best accomplished using minimal local anesthetic placed in the pretarsal orbicularis oculi muscle.

Commonly used local anesthetic agents includelidocaine (Xylocaine) 2% and the longer-acting bupi-

vacaine (Marcaine) 0.5% As a vasoconstrictor,

epi-nephrine 1 : 100,000 or 1 : 200,000 is useful in reducing

operative hemorrhage and slows the systemic

absorp-tion of local anesthetic, thereby prolonging the

dura-tion of anesthesia Hyaluronidase is only rarely

required but, if used, may facilitate the spread of the

anesthetic through tissue planes

Discomfort associated with the local injection isgenerally due to acidity of premixed solutions of lido-

caine containing epinephrine This may be avoided by

a two-stage injection technique using a 28-gauge

nee-dle to initially inject a mixture of dilute local

anes-thetic before infiltrating with the complete mixture

The first-stage injection consists of lidocaine 0.1% in

injectable saline solution, warmed to body

tempera-ture if possible, and is followed by the full-strength

second-stage injection a few minutes later

Asepsis

Oculoplastic surgery is performed in a modern

oper-ating theater environment exercising standard

meth-ods of infection control Aqueous povidone-iodine

solution is used to clean and prepare the skin,

although chlorhexidine may be substituted if the

patient is allergic to iodine Because these substances

are irritating to the conjunctiva, it is important to

irri-gate the eye immediately if there is inadvertent

exposure

Due to the extensive palpebral vascular supply, theeyelids are remarkably resistant to infection The role

of prophylactic antibiotics before and during surgery

is controversial, but may be of value in cases

involv-ing the sinuses, trauma, preoperative infection, or

orbital or lacrimal reconstruction.16, 17

Incisions

The ideal incision allows maximal access to the geon while minimizing visible scarring A preopera-tive discussion with the patient regarding the skinincision is mandatory and the site marked before infil-tration with local anesthetic

sur-A cutaneous scar can be avoided altogether byusing transconjunctival approaches for eyelid ororbital surgery (Figs 2–3 and 2–4).18Alternatively, thescar may be hidden by the hairline as is the case with

a coronal incision for endoscopic brow lifting Theincision should be placed in preexisting skin creaseswhere possible, utilizing, for example, the upper lidskin crease for surgery in the upper part of the orbit.19Otherwise incisions should be aligned parallel to therelaxed skin tension lines of the face (Fig 2–5).20The skin is held taut, to avoid beveling or irregularwound edges, and the incision made perpendicular

B A

FIGURE 2–4 (A)A 25-mm-diameter dermoid cyst being removed through a medial left transconjunctival approach

(globe indicated by arrow) (B) Everted upper eyelid (white arrow) showing large conjunctival cyst exposed through

an upper fornix incision (black arrows).

FIGURE 2–5 Relaxed skin tension lines of the face,

including periocular skin.

to the surface to reduce scarring An exception is in

hair-bearing areas, such as the brow or scalp, where

the incision is angled parallel to the hair shafts to

avoid damage to the follicles The incision is

com-pleted in a single steady motion, starting from the

lowest point of the operating field and working

upward, so as to avoid blood obscuring the view

Consideration of the lymphatic drainage is tant before any lid surgery, since a poor lymphatic

impor-outflow can adversely affect wound healing

(Fig 2–6).21 The normal lymphatics of the eyelidextend posteroinferiorly from the lateral eyelids to thepreauricular and submandibular lymph nodes Verti-cal incisions in the lateral canthus are thus highly dis-ruptive to lymphatic outflow, while medial canthalvertical incisions are less problematic

Instruments and Tissue Handling

Instruments for oculoplastic surgery are larger thanthose used for intraocular surgery, but generallysmaller and more delicate than those used in generalplastic surgery It is important to use the appropriateinstrument for a given procedure, to minimize tissuetrauma that would impede wound healing To allowgripping of tissues without crushing, forceps should

be toothed rather than smooth, and scissors mustalways be sharp The size of instrument chosen shouldalso be of appropriate strength, such that the ruggedAdson forceps is used for scalp flaps requiring trac-tional manipulation, whereas the smaller, toothedJayle’s forceps are more suitable for eyelid work withrelatively stationary tissue handling Similarly West-cott spring-action scissors are extremely useful for finework, whereas the sharp straight scissors are bettersuited for cutting tougher tissues, such as skin flaps orlarge skin-muscle flaps Fine skin hooks are of particu-lar use in retracting tissue flaps with minimal trauma.Orbital and lacrimal surgery demand sturdierinstruments, which include rongeurs, bone saws,

FIGURE 2–6 Persistent edema of right lower eyelid following injury running across lines of lymphatic drainage.

(A) Four weeks after injury with marked edema (B) Six months later with resolution.

B A

P I T F A L L

Chronic severe eyelid lymphedema mayresult from simultaneous vertical incisions ofmedial and lateral canthi on the same eyelid

Cautery allows immediate intraoperative stasis with minimal tissue destruction and is achievedusing thermal, electrocautery, or laser modalities Bat-tery-powered high-temperature thermal cautery(2200°C) is useful for oculoplastic surgery, unlike thelow temperature (1000°C) instrument, which is onlysuitable for conjunctiva or fine ocular tissues.

hemo-High-frequency electrocautery (diathermy) can beused for dissecting as well as cauterizing tissue,depending on the electromagnetic waveform emanat-ing from the tip In monopolar mode an indifferentelectrode is attached to the patient’s thigh or buttock,allowing the instrument to be used for either cutting

or coagulation.24Since current passes through thepatient, monopolar electrocautery is contraindicated

in the presence of a cardiac pacemaker, and careshould be exercised to keep the indifferent electrodedry during surgery—otherwise skin burns may result.Bipolar electrocautery does not require an extra elec-trode and allows direct coagulation of vessels that can

be held between the diathermy forceps It is also ful for shrinking prolapsed orbital fat during surgery,which obviates the risk of bleeding associated withexcising fat Bipolar electrocautery provides highlylocalized coagulation and, therefore, is ideal whenworking in the posterior part of the orbit where theoptic nerve would otherwise be at significant risk ofinjury.25The carbon dioxide laser can also be used forcutting or coagulation, depending on the intensityand duration of the beam, and is particularly useful inthe presence of vascular scar tissue.26

use-Topical thrombogenic agents are useful when orrhage is so diffuse that cautery is impractical, asseen with the mucosal surface bleeding during anexternal dacryocystorhinostomy Examples includeabsorbable gelatin foam (Gelfoam), charged collagenproducts (Collistat, Helistat), oxidized cellulose (Sur-gicel, Oxycel) and microfibrillar collagen (Avitene).All may be left in the eyelids or orbit, apart from theoxidized cellulose products, which cause unaccept-able degrees of inflammation Bone wax is extremelyuseful to control bleeding from the bone and can beapplied directly to sites of hemorrhage, especiallyduring orbital surgery

hem-Suture Materials

A wide variety of sutures are available to the plastic surgeon and these can be broadly classifiedinto absorbable or nonabsorbable types They may bebraided or monofilament, and constructed from nat-ural or synthetic material (Tables 2–1 and 2–2) Con-siderations influencing choice of suture include tissuetype, wound tension, potential for tissue reaction andinfection, handling characteristics, patient tolerance,and pigmentation

oculo-drills, and plating sets Endoscopic surgical

instru-mentation now permits a further means of accessing

lacrimal and orbital structures, allowing transnasal

lacrimal surgery and posterior orbital work such as

orbital or optic canal decompression.22

A scalpel with a disposable supersharp blade, such

as the Bard-Parker 15, is excellent for most skin

inci-sions Alternatively, the carbon dioxide laser or

high-frequency unipolar cutting electrocautery enable

virtually bloodless dissection and are appropriate in

revision surgery with markedly vascular scar tissue

P EARL Use toothed forceps of

appropriate size to avoid crushing tissue during manipulation.

Hemostasis

The rich vascular supply of the eyelids and ocular

adnexa promotes healing and reduces the risk of

infection, but also makes hemostasis a challenge

Excessive hemorrhage prolongs operating time and

may lead to a postoperative orbital hematoma, which

may impede wound healing or lead to visual loss

A history of abnormal bleeding should be cally sought and the patient’s medication list scruti-

specifi-nized Aspirin and nonsteroidal antiinflammatory

drugs should be stopped at least 14 days before

surgery, although it may not be possible to

discon-tinue anticoagulants in certain patients If surgery is

essential in these cases, admission to hospital and

con-version to intravenous heparin may be required, this

being stopped just prior to surgery and recommenced

postoperatively

Perioperative blood pressure control should beoptimal, ensuring that patients continue to take their

medications if hypertensive, and hypotensive

anes-thesia may be required for complex orbital surgery

Addition of vasoconstricting drugs, such as 1 : 100,000

epinephrine, to infiltration local anesthesia

signifi-cantly reduces intraoperative hemorrhage Similarly,

topical intranasal cocaine 4%, intranasal

oxymetazo-line 0.05%, or conjunctival phenylephrine 2.5% or 10%

may be used during nasolacrimal or

transconjuncti-val surgery to markedly reduce hemorrhage at these

sites

Intraoperative hemostasis is achieved using sure tamponade, cautery, and topical thrombogenic

pres-drugs.23Pressure tamponade represents the simplest

method, but has the disadvantage of taking a

rela-tively long time (up to 10 minutes) to achieve control

and often produces a rather fragile clot, which can be

easily dislodged

T ABLE 2–1 A BSORBABLE S UTURES

Time to lose 50% Synthetic lament tensile (S) or (M) or Suture (days) natural braided material strength (N) (B)

Nonabsorbable sutures should be removed within

10 days and are often used for skin closure, since they

induce much less tissue reaction than absorbable

sutures Synthetic sutures, such as polyglactin

(Vicryl), are broken down by hydrolysis and are

absorbed more slowly than natural material, such as

catgut, which is degraded enzymatically Compared

to monofilament, braided sutures are easier to handle

but are thought to be associated with a higher rate of

infection It should be noted that silk causes

signifi-cantly more inflammation, suture tracks, and

ab-scesses than other nonabsorbable synthetic materials,

and, therefore, should probably not be a suture of first

choice Stainless steel wire is occasionally used for

canthal reconstruction, causing little reaction if well

buried, but with minimal advantage over larger

gauge nonabsorbable artificial sutures, such as

polypropylene

Patient tolerance and pigmentation further ence choice of suture Polypropylene or nylon is less

influ-painful to remove than silk when the suture has been

left in place for a while, as with, for example, a

bol-stered intermarginal eyelid suture In children, an

absorbable suture is preferred for skin closure, to

avoid removal at a later stage

Needles

Four main needle configurations are available to the

oculoplastic surgeon (Fig 2–7): The cutting needle is

triangular in cross section with a sharp cutting edge

along the inner diameter of a circle The reverse

cut-ting needle is similar, but with a cutcut-ting edge along the

outer diameter The spatula needle is flatter with sharp

sides and is useful for partial-thickness tarsal or

scle-ral sutures Round needles are for loose connective

tis-sue, but are generally not used in oculoplastic surgery

since they are difficult to pass through the relatively

tough structures of the eyelid Half-circle needles are

3 8

excellent for confined spaces such as the medial andlateral canthi and for lacrimal surgery Longer com-pound-curved needles are very useful for suturingdeeply during socket reconstruction, whereas slightlycurved needles are more helpful for suturing eyelidand tarsus

Wound Closure

The goal of optimal wound closure is to achieve anaesthetically acceptable result with minimal scarring.The wound should be prepared so that necrotic tissue

is removed and the margins straight with no raggedtissue Any foreign bodies or clots should be removedand the wound thoroughly debrided in cases oftrauma or infection Care is taken to prevent tissuefrom drying out, as this distorts tissue planes andretards healing

All wounds should be closed in appropriate layers

so as to eliminate any dead space and relieve tension

on the wound Deeper tissues are closed usingabsorbable sutures with the knot buried downwardcarrying most of the tension, whereas skin is closed

T ABLE 2–2 N ONABSORBABLE S UTURES

Suture Synthetic (S) Monofilament (M) material or natural (N) or braided (B)