Eye Emergencies : The Practitioner’s Guide (Second Edition) by Dorothy Field, Emma Whittingham, and Julie Tillotson


0040d579_medium.jpg Author Dorothy Field, Emma Whittingham, and Julie Tillotson
Isbn 9781905539956
File size 27MB
Year 2015
Pages 204
Language English
File format PDF
Category medicine



 

eye 2 prelims:M&K 1 16/02/2015 10:53 Page i Eye Emergencies The practitioner’s guide 2nd Edition eye 2 prelims:M&K 1 16/02/2015 10:53 Page ii eBook version also available Eye Emergencies: The practitioner’s guide 2nd Edition ISBN: 9781907830952 For the full range of M&K Publishing books please visit our website: www.mkupdate.co.uk eye 2 prelims:M&K 1 16/02/2015 10:53 Page iii Eye Emergencies The practitioner’s guide 2nd edition Dorothy Field Julie Tillotson Emma Whittingham eye 2 prelims:M&K 1 16/02/2015 10:53 Page iv Eye Emergencies: The practitioner’s guide 2nd edition Dorothy Field, Julie Tillotson & Emma Whittingham ISBN: 9781905539-95-6 First published 2008, this edition published 2015 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior permission of the publishers or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London, W1T 4LP. Permissions may be sought directly from M&K Publishing, phone: 01768 773030, fax: 01768 781099 or email: [email protected] Any person who does any unauthorised act in relation to this publication may be liable to criminal prosecution and civil claims for damages. British Library Catalogue in Publication Data A catalogue record for this book is available from the British Library. Notice Clinical practice and medical knowledge constantly evolve. Standard safety precautions must be followed, but, as knowledge is broadened by research, changes in practice, treatment and drug therapy may become necessary or appropriate. Readers must check the most current product information provided by the manufacturer of each drug to be administered and verify the dosages and correct administration, as well as contraindications. It is the responsibility of the practitioner, utilising the experience and knowledge of the patient, to determine dosages and the best treatment for each individual patient. Any brands mentioned in this book are as examples only and are not endorsed by the publisher. Neither the publisher nor the authors assume any liability for any injury and/or damage to persons or property arising from this publication. Disclaimer M&K Publishing cannot accept responsibility for the contents of any linked website or online resource. The existence of a link does not imply any endorsement or recommendation of the organisation or the information or views which may be expressed in any linked website or online resource. We cannot guarantee that these links will operate consistently and we have no control over the availability of linked pages. To contact M&K Publishing write to: M&K Update Ltd · The Old Bakery · St. John’s Street Keswick · Cumbria CA12 5AS Tel: 01768 773030 · Fax: 01768 781099 [email protected] www.mkupdate.co.uk Designed & typeset in 11pt Usherwood Book by Mary Blood Printed in England by H&H Reeds, Penrith. eye 2 prelims:M&K 1 16/02/2015 10:53 Page v Contents List of illustrations vii About the authors viii About this book ix Acknowledgments x Chapter 1: Anatomy and physiology of the eye 1 Protection of the eye 1 The conjunctiva 4 The lacrimal apparatus 5 The external eye muscles 7 The eye 8 The optic pathways 15 References 16 Chapter 2: Initial assessment 17 Ophthalmic triage 17 Recording an eye history 19 Vision testing 20 Basic eye examination kit 25 Eye examination with a pen torch 26 Slit lamp examination 31 References 32 Differential diagnosis guide: acute red eyes 33 Visual Disturbance assessment chart 34 Chapter 3: Differential diagnosis of emergency eye conditions 37 Chemical injuries 38 Major eye injuries 44 Acute glaucoma 48 Ophthalmia neonatorum 53 Orbital infections 55 Sudden painless loss of vision 58 Sudden loss of vision with pain 66 Hypopyon and hyphaema 69 References 72 Chapter 4: Major accidents and injuries 75 Accidents and injuries 75 Infections 88 Recurrent erosion of the cornea 92 Corneal inflammations 93 Corneal infections 96 Uveal tract disorders 101 Visual perception disorders 104 Post-operative related eye problems 107 References 108 Chapter 5: Non-urgent eye conditions Face and eyelids 111 111 eye 2 prelims:M&K 1 16/02/2015 10:53 Page vi Conjunctival problems 123 Differential diagnosis guide: types of conjunctivitis 129 Scleral problems 135 Other presentations 137 References 139 Chapter 6: Drugs commonly used for acute eye conditions 141 General principles 141 Pregnancy and lactation 142 Eye drops and contact lens wear 142 Acute glaucoma 143 Antibiotics 144 Antihistamine and mast cell stabilisers 145 Antivirals 146 Steroids 146 Lubricants 147 Local anaesthetics 148 Pupil dilators 148 Diagnostic eye drops 150 References 151 Chapter 7: Ophthalmic pain 153 General principles 153 Severe aches 153 Stabbing pain 154 Children and eye pain 156 Ophthalmic sensation table 150 References 157 Chapter 8: Concluding notes 159 The changing face of ophthalmic ED provision 159 Telephone triage 159 Instructions for all eye emergency patients on discharge 161 Practitioner responsibilities 162 Patient Assessment – Eye Accident and Emergency flow chart 163 Signs & Symptoms based Ophthalmic Triage Tool 164 Record of Telephone Triage Advice – Eye Unit 166 Chapter 9: Ophthalmic procedures 167 Irrigating an eye 167 Checking the pH of an eye 169 Everting an eyelid 169 Checking eye movements 171 Checking for relative afferent pupillary defect (RAPD) 172 Visual fields by confrontation 173 Seidel test to detect a wound leak 174 Corneal staining with fluorescein 175 Application of heat to the eyelids 176 References 178 Glossary of ophthalmic terms 179 Index 185 eye 2 prelims:M&K 1 16/02/2015 10:53 Page vii List of illustrations 1.1 The eyelid 2 1.2 Conjunctival fornices 4 1.3 The lacrimal apparatus 5 1.4 The tear film 6 1.5 The external eye muscles 7 1.6 The whole eye 8 1.7 The cornea 9 1.8 Drainage angle 10 1.9 The optic pathways 15 3.1 Severe chemical injury 39 3.2 Penetrating injury 44 3.3 Acute glaucoma 50 3.4 Neovascular (rubeotic) glaucoma 52 3.5 Preseptal cellulitis 56 3.6 Orbital cellulitis 57 3.7 Central retinal artery occlusion 60 3.8 Central retinal vein occlusion 62 3.9 Vitreous haemorrhage 64 3.10 Hypopyon 69 3.11 Hyphaema 70 4.1 Full thickness eyelid laceration 78 4.2 Corneal foreign body 85 4.3 Herpes zoster ophthalmicus 88 4.4 Acute dacryocystitis 90 4.5 Corneal neovascularisation - contact lens overuse 94 4.6 Bacterial corneal ulcer 97 4.7 Herpes simplex keratitis (dendritic ulcer) 99 4.8 Acanthamoeba keratitis 100 5.1 Bell's palsy 112 5.2 Blepharitis 115 5.3 Stye 120 5.4 Chalazion 121 5.5 Viral conjunctivitis 127 5.6 Subconjunctival haemorrhage 131 9.1 Cardinal eye positions 172 vii eye 2 prelims:M&K 1 16/02/2015 10:53 Page viii About the authors Dorothy Field RGN, OND, BSc(Hons), PGCE(A), MA, EdD Retired Lecturer Practitioner, Bournemouth Eye Unit Julie Tillotson RGN, OND, BSc(Hons) Independent and Supplementary Prescriber Advanced Nurse Practitioner Bournemouth Eye Unit and Community Eye Clinic Adam Practice Emma Whittingham Adv Dip, BSc(Hons), MSc Nurse Practitioner, Independent and Supplementary Prescriber Advanced Nurse Practitioner Bournemouth Eye Unit viii eye 2 prelims:M&K 1 16/02/2015 10:53 Page ix About this book This book is intended for anyone whose work involves dealing with acute ophthalmic presentations. We have used the term ‘practitioner’ to include doctors, ophthalmic nurses, emergency care practitioners, nurse practitioners, nurses in accident and emergency departments and ‘walk in’ centres and first aid workers in remote locations such as oil rigs or working in the armed services. Readers will approach this text with differing levels of confidence, skills and knowledge. We hope this book will help them develop greater competence in ophthalmic emergency practice. As a slim volume for quick reference, this book cannot include information such as how to put people at ease, ensure confidentiality and care for the specific needs of children, disabled people or other groups with particular needs. We have assumed that any professional given the responsibility of practising care at this level will either already have most of these skills or be seeking other ways to learn and develop them. The flag system Throughout this book, we have used a system of flag symbols in the margins to highlight the diagnostic significance of symptoms described in a particular context. A red flag An amber flag indicates a highly significant symptom. indicates a symptom that should be treated with caution as a diagnostic tool. ix eye 2 prelims:M&K 1 16/02/2015 10:53 Page x Acknowledgments The authors wish to acknowledge the contributions of Julie Cartledge, David Goorapah, Helen Storr and Linda Witchell for reading Edition 1 early drafts and making constructive suggestions regarding amendments to the text; Sue Cox for designing the telephone triage form and Sam Hartley for her photography. We would also like to thank Graham Giddens for his help in checking references and for proof reading the second edition. The diagrams in this book have been redrawn, based on originals by Peter Jack in Ophthalmology for Nurses, Gaston H., Elkington A., 1986, Croom Helm Publishers. The authors would like to thank the following for their kind permission to use photographs: Amanda MacFarlane (front cover photograph) David Etchells Eric P. Suan, M.D., F.A.C.S, The Retina Care Center, Baltimore, Maryland, USA Manchester Royal Eye Hospital, Manchester, UK The Cogan Collection, National Eye Institute, National Institute of Health, Bethesda, Maryland, USA x Eye 2 ch 1:M&K 1 16/02/2015 10:54 Page 1 Chapter 1 Anatomy and physiology of the eye This chapter contains some very basic information to get you started. Study of more detailed texts is recommended as your knowledge of this subject grows. A few notes are offered regarding ‘clinical significance’ to demonstrate the need to apply textbook knowledge to actual eye disorders in order to develop your own understanding of symptoms and treatments. Protection of the eye The orbit Protection of the eye As a complex, delicate and superficial organ, the eye is reasonably well protected within the bony orbit. The frontal bone of the brow juts out slightly, protecting the eye from many of the larger blunt injuries encountered, such as footballs. This, in combination with the other bones of the orbital rim, maxillary bone and zygomatic bone, makes an exterior protective rim, within which the eye sits. Blunt injuries may result in orbital rim fractures. Orbital fat pads out the available space around the eye, the external muscles of the eye, blood vessels and nerves, and acts as a ‘shock absorber’ in the event of a direct or indirect impact in the orbital region. A ‘blow out fracture’ most commonly affects the orbital floor, the superior aspect of the maxillary bone, but the ethmoid bone, which forms the medial wall of the orbit, is sometimes also involved. Clinical significance Eye departments and ophthalmologists are concerned with the function of the eye itself. Although they do see patients with orbital fractures, their remit is primarily the health and function of 1 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 2 Eye Emergencies: The practitioner’s guide the eye itself. Other specialisms take responsibility for the management of head injuries and orbital fractures, having consulted the ophthalmologist regarding possible associated eye trauma. Occasionally an infection spreads to the tissues surrounding the eye, within the orbit (orbital cellulitis), which may be managed either by the ophthalmology or Ear, Nose and Throat (ENT) departments, depending on whether the infection arose from the structures immediately surrounding the eye or from the facial sinuses. The eyelids These comprise the next protective structure for the eye. The eyelids close reflexively when a threat is perceived, and the cilia (eyelashes), when touched, will also cause the eye to close rapidly. The skin covering the eyelids is loose and thin and readily accommodates considerable rapid swelling of the eyelid tissue in response to allergy or injury. Figure 1.1 The eyelid 2 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 3 Anatomy and physiology of the eye Muscles of the eyelids The orbicularis oculi muscle has three functions. l It is a sphincter muscle which firmly closes the eyelids, and is particularly efficient in young children. Indeed, a baby squeezing the eyelids shut whilst a practitioner is struggling hard to open them, can cause the upper eyelid to evert spontaneously. l The blink function of the orbicularis muscle ensures the frequent and even distribution of tears across the eye. l The slightly lateral action of the muscle across the eye helps to draw small quantities of tears from the lacrimal gland and closure of the eyelids by the orbicularis muscle helps to suck excess tears into the lacrimal punctae. The frontalis muscle from the forehead, the long levator muscle and the shorter Müller’s muscle all work together to raise the eyelid. Within the eyelids The glands of Zeiss are sebaceous and lipid-secreting glands associated with eyelash follicles, the sebum from which contributes to the tear film. The glands of Moll are specialised sweat glands, also associated with eyelash follicles. The meibomian glands are located between the tarsal plates and conjunctiva lining the eyelids and produce sebum and lipids, which also contribute to the tear film of the eye. There are about 30 of these glands in the upper eyelid of each eye, and slightly less in the lower eyelids. Their orifices are visible along the margins of the eyelids when examining the eye with a slit lamp. They can also be seen through the conjunctiva when the eyelid is everted. Meibomian glands can become blocked and infected at any age. The accessory lacrimal glands of Krause and Wolfring are situated in the fornices of the upper and lower eyelids. The tarsal plates are composed of dense fibrous tissue and provide support and shape to the eyelids and a fair amount of protection against injury to the eyeball itself. The tarsal plates are larger, half moon shapes in the upper eyelids, and thinner and smaller in the lower eyelids, and of an elliptical shape. 3 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 4 Eye Emergencies: The practitioner’s guide Clinical significance In a facial palsy, the eye may undergo exposure and dryness or other injury due to the failure of the eyelids to close efficiently. Inadequate eyelid closure may also occur as a result of growths on the eyelids, injuries to the eyelids or unskilled eyelid surgery. The conjunctiva Figure 1.2 Conjunctival fornices The conjunctiva 4 The conjunctiva is a thin, transparent mucous membrane that lines the eyelids (known as the palpaebral conjunctiva) and folds back on itself to make the upper and lower fornices. These fornices, or ‘pockets’ are significant in that loose foreign bodies and misplaced contact lenses are never completely irrecoverable. The conjunctiva is loosely attached to the anterior part of the sclera (this section is called the bulbar conjunctiva) until it reaches the cornea. The bulbar conjunctiva contains goblet cells, which secrete mucin, an important constituent of the tear film. The very loose attachment of the conjunctiva to the globe makes it an area that can become swollen – conjunctival chemosis – in response to inflammation or allergy. It is also a useful site for subconjunctival injections of antibiotics or steroid drugs to treat some eye conditions. Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 5 Anatomy and physiology of the eye The bulbar conjunctival blood vessels are very fine and are not generally apparent in the normal healthy eye. The conjunctiva ends at the limbus where it merges with the sclera and cornea. Clinical significance The appearance of the conjunctiva inside the eyelids and across the front of the globe provides useful diagnostic clues. Scarlet inflammation, primarily inside the eyelids and distal to the cornea, may indicate conjunctivitis. A generalised crimson redness of the conjunctiva, taken together with other critical signs, may indicate an acute (‘congestive’) glaucoma. Patches of redness, especially of a pinky purple appearance may indicate a problem with the sclera. Scarlet areas of dilated blood vessels may develop distal to a corneal problem such as an ulcer or foreign body. Tiny pinky purple inflamed vessels around the edge of the cornea may indicate an anterior uveitis or keratitis. Similarly the quality and appearance of any discharge from the conjunctiva needs to be noted and evaluated as a diagnostic step. See the differential diagnostic guides for acute red eye (in ‘The conjunctiva’, page 28) and types of conjunctivitis (page 129). The lacrimal apparatus Figure 1.3 Lacrimal apparatus 5 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 6 Eye Emergencies: The practitioner’s guide The lacrimal gland This is about the size and shape of an almond, located at the upper temporal side of each eye, within the lacrimal fossa of the frontal bone of the skull. It has a row of tiny openings which discharge tears across the front of the eye, assisted by the blinking actions of the eyelids. It is, however, the accessory lacrimal glands of Krause and Wolfring which supply the general contribution to the aqueous layer of the tear film. The lacrimal gland produces larger, immediate quantities of tears in response to foreign bodies or chemicals, trauma and disruption of the cornea and emotional upsets. The blinking actions of the eyelids, combined with gravity, cause the tears to be swept down across the front of the eye towards the upper and lower punctae in the nasal corners of each eye, through the upper and lower canaliculi into the common canaliculus, and from there into the lacrimal sac, through the nasolacrimal duct and into the nose. Clinical significance Disorders of either the production or drainage of tears can be inconvenient and at worst potentially damaging to eye health. The tear film Figure 1.4 Tear film The tear film has four main functions: l to prevent the cornea from drying out l to convey nutrients and oxygen to the cornea as it has no direct blood supply l to keep the cornea clean and to protect this smooth refractive surface of the eye l to provide protection against infection. 6 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 7 Anatomy and physiology of the eye The healthy tear film is complex, consisting of three layers. Mucin, the innermost layer, secreted by the goblet cells of the bulbar conjunctiva, clings effectively to the corneal epithelium and its hydrophilic (water attracting) property enables the aqueous (watery) layer to be retained on the surface of the eye. Aqueous humour, the middle layer of the tear film, is secreted by the glands of Krause and Wolfring. This watery layer contains lysozyme, an enzyme which also occurs in nasal secretions and gastric juices, which has a cytoprotective and bacteriostatic action against a range of pathogens (Fleiszig et al. 2003, Minjian et al. 2005). The lipid (oily) layer, supplied by the meibomian glands and the glands of Zeiss inhibits evaporation of the tear film, and helps to retain the aqueous on the surface of the eye. Clinical significance Given the different areas that produce the components of the tear film, it can easily be seen that a problem with any part of the process will lead to a dysfunctional tear film with attendant problems, notably for the cornea. Always discourage patients from making regular use of proprietary eye washing solutions that will wash away the tear film and the protective lysozyme. The external eye muscles Figure 1.5 External eye muscles 7 Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 8 Eye Emergencies: The practitioner’s guide There are three pairs of external muscles to move the eyes horizontally, vertically, clockwise and anticlockwise. Each eye has: l superior and inferior rectus, lateral and medial rectus l superior oblique and inferior oblique muscles. Normally, these muscles move both eyes together in synergy, to produce good binocular vision. Clinical significance The external eye muscles need to work efficiently in order for children to develop adequate vision in both eyes (hence a childhood squint sometimes leads to ‘lazy eye’ in adults), to prevent double vision in adults and to retain a satisfactory cosmetic appearance. The eye The eye Figure 1.6 The whole eye 8 The eye itself is sometimes referred to as ‘the globe’, as in ‘ruptured globe’ to disassociate it from the other, extra-ocular structures described above. Eye 2 ch 1:M&K 1 16/02/2015 10:55 Page 9 Anatomy and physiology of the eye The cornea Figure 1.7 The cornea The cornea has three main functions. l It provides a clear window for light rays to pass through. l It is responsible for about two-thirds of the eye’s refractive power. l It provides protection for the structures that lie behind it. The limbus is a transitional area, where the cells of the sclera become rapidly avascular and more transparent, merging into the corneal tissue. The cornea is extremely sensitive, as it contains more nerve endings than anywhere else in the body. It is only about half a millimetre thick and is composed of five layers, listed below from the outermost inwards. l Epithelium – consists of layers of cells with an overall depth of five to six cells. These cells are capable of regeneration if damaged. l Bowman’s membrane – is a strong collagen membrane, which, if injured, for example with the removal of a corneal foreign body, will heal as a white scar within a transparent cornea. l Corneal stroma – this represents 90 per cent of the thickness of the cornea. Its lamella sheets are composed of tiny collagen fibrils to give the cornea its clarity. Damage to this also produces white scar tissue. l Descemet’s membrane – is the strong, thin elastic basement membrane of the cornea. 9

Author Dorothy Field, Emma Whittingham, and Julie Tillotson Isbn 9781905539956 File size 27MB Year 2015 Pages 204 Language English File format PDF Category Medicine Book Description: FacebookTwitterGoogle+TumblrDiggMySpaceShare The second edition of Eye Emergencies offers an excellent up-to-date resource for anyone whose work involves dealing with acute ophthalmic presentations. The authors have used the term ‘practitioner’to include doctors, ophthalmic nurses, emergency care practitioners, nurse practitioners, nurses in accident and emergency departments and ‘walk in’centres and first aid workers in remote locations such as oil rigs or working in the armed services. Aimed at readers with differing levels of confidence, skills and knowledge, Eye Emergencies will help all practitioners develop greater competence in ophthalmic emergency practice. The system of flag symbols in the margins, highlighting the diagnostic significance of symptoms described in a particular context, makes this book particularly useful for quick reference. Contents include: Anatomy and physiology of the eye Initial assessment Differential diagnosis of emergency eye conditions Urgent eye conditions Non-urgent eye conditions Drugs commonly used for acute eye conditions Ophthalmic pain Concluding notes Ophthalmic procedures Glossary of ophthalmic terms Index     Download (27MB) Fast Facts: Ophthalmology Book Alone: Cancer Symptom Management, 4 Edition Emergency Care of Minor Trauma in Children Palliative Care, 2nd Edition Physiology And Anatomy For Nurses And Healthcare Practitioners: A Homeostatic Approach, Third Edition Load more posts

Leave a Reply

Your email address will not be published. Required fields are marked *