Chemical Ocular Burns (eBook)

Prof. Dr. Norbert SCHRAGE is Director of the Ophthalmology Hospital in Cologne. One focus of his work in both the clinical and the research environment is the treatment of eye burns, and more specifically the development of new rinsing solutions for such purposes. He follows a very interdisciplinary approach to solve clinical problems with input from medical, chemical and engineering experts. Another main area of research of Prof. Schrage is the development of keratoprosthesis.

Chemical Ocular Burns 1
Copyright Page 3
List of Authors 4
Foreword 5
Preface 7
Contents 9
1: History of Chemical Burns and Relative Treatments 10
1.1 Burns for Doctors in Antiquity 10
1.1.1 Chemical Burns Since Antiquity 12
1.1.2 Treatment of Thermal and Chemical Burns in the Second Half of Twentieth Century, the Revolution of Intensive Care 13
1.1.3 History of the Treatment of Chemical Skin Burns 14
1.1.4 Conclusion 14
1.2 Modern History of the Chemical Burns 14
1.2.1 Burns, a Disease of Different Origins 14
1.2.2 Start of Medical Treatment 15
1.2.3 Research in Toxicology and Ophthalmology 15
1.2.4 Rinsing Therapy 15
1.2.5 Classification of Eye Burns 15
1.2.6 Specific Treatment Options 16
1.2.7 Future and Present of Reconstitutive Concepts 16
References 16
2: Epidemiology of Ocular Chemical Burn Injuries 18
2.1 Introduction 18
2.2 Data Limitations and Scope of the Problem 18
2.2.1 Individual Publications/Case Series 18
2.2.2 American Association of Poison Centers National Poison Data System (NDPS) 19
2.2.3 US Bureau of Labor Statistics Data 19
2.3 Etiology 20
2.3.1 Work-Related Injury 20
2.3.2 Deliberate Chemical Assault 20
2.3.3 Complications of Face Peeling 22
2.3.4 Burn Center/Hospital Studies 22
2.4 Involved Chemicals 23
2.5 Conclusions 23
References 23
3: The Chemical Agents and the Involved Chemical Reactions 25
3.1 From Chemistry to Symptoms 25
3.1.1 What Is a Chemical Burn? 25
3.1.2 What Are the Parameters Affecting the Chemical Burn? 25
3.1.3 Extent of the Matter 25
3.2 The Chemical Agent 26
3.2.1 Molecular Structure of an Irritant or a Corrosive 26
3.2.2 Reactive Functional Groups of Irritant or Corrosive Agents 27
3.2.2.1 Acidic Function 27
3.2.2.2 Basic Function 27
Energy Scale of Acid–Base Reactions: The pK Notion 27
3.2.2.3 Oxidizing Function 27
3.2.2.4 Reduction Function 28
3.2.2.5 Solvent Function 28
3.2.2.6 Chelating Function or Complexation 29
Energy Scale of Chelation Reactions 29
3.2.2.7 Alkylation Reaction 29
Reactivity Scale for Alkylating Agents 30
3.2.2.8 Molecular Reactivity and Chemical Bonds: Main Aspects 30
3.2.3 Modulation of the Expression of the Reactivity of a Molecule 30
3.2.3.1 Acetic Acid and Its Derivatives 30
3.2.3.2 Hydrofluoric Acid 31
3.2.3.3 Phenol 31
3.2.3.4 Methylamines Series 32
3.2.3.5 Last Illustration: Acrolein 32
3.2.4 Energetic Levels of the Chemical Reactivity 33
3.2.4.1 Acid–Base Scale 33
3.2.4.2 Prediction of the Irritant Power of Acids or Bases 35
3.2.4.3 Scales of Energy Level 35
3.3 Constituents of the Tissues: Which Are the Biological and Biochemical Targets? 37
3.4 The Mechanisms of the Chemical Burn During the Contact Between the Aggressor and the Eye 39
3.4.1 The Different Elementary Types of Chemical Reactivity 39
3.4.2 Energy Dimension of Chemical Burns 41
3.4.3 Key Parameters of Chemical Burns 42
3.4.3.1 Danger Resulting of the Nature of the Involved Chemical 43
Solid Form 43
Viscosity 43
Exothermic Reaction 44
Titanium Tetrachloride 44
Trichloromethylsilane 45
Boron Trifluoride 45
Sulfuric Acid 46
3.4.3.2 Risk Factors in Relation with the Conditions of Use 47
Concentration of the Chemical 47
Phenomenon of the Diffusion of Corrosives in Relation with Their Concentration 48
Time of Contact 49
Temperature 50
Pressure 51
3.5 Practical Conclusions in Order to Manage the Optimal Chemical Decontamination of an Eye 51
3.5.1 The First Reflex: The Passive Wash Including Dilution and Mechanical Draining 51
3.5.2 Consequences of a Passive Washing: A Longer Time of Action 52
3.5.3 The Concept of Active Wash 52
3.6 What is Now the Extent of Our Knowledge About Ocular Chemical Burns? 54
References 56
4: Histology and Physiology of the Cornea 57
4.1 Corneal Functions 57
4.2 Anatomy Reminder 57
4.3 Histology 57
4.3.1 The Epithelium and Its Basement Membrane 57
4.3.1.1 The Lacrymal Secretion 57
4.3.1.2 The Corneal Epithelium 58
4.3.1.3 The Superficial Cells 58
4.3.1.4 The Intermediate Cells 59
4.3.1.5 Basal Cells 59
4.3.1.6 The Basement Membrane 60
4.3.2 Bowman’s Membrane 60
4.3.3 The Stroma 60
4.3.3.1 Keratocytes 60
4.3.3.2 The Collagen Lamellae 61
4.3.3.3 Ground Substance 61
4.3.3.4 Other Cells 61
4.3.4 Descemet’s Membrane 61
4.3.5 The Endothelium 61
4.3.6 The Limbus 62
4.4 Vascularization 63
4.5 Innervation 63
4.6 Factors of the Corneal Transparency 63
4.6.1 The Collagen Structure 63
4.6.2 The Proteoglycans Function 63
4.6.3 The Absence of Vascularization 63
4.6.4 The Scarcity of Cells in the Stroma 63
4.6.5 The Regulation of the Hydration 63
4.6.6 Mechanism of Recovery of the Corneal Transparency in case of a Burn 64
4.6.6.1 The Limbus 64
4.6.6.2 The Stroma 65
4.6.7 Action of the Intraocular Pressure 65
References 65
5: Physiopathology of the Cornea and Physiopathology of Eye Burns 66
5.1 Physiology of the Cornea 66
5.1.1 Eye Burns Physiological Barriers 66
5.1.2 Physiological Mechanisms of Decontamination on the Eye 66
5.1.3 Physiology of Local Decontamination 68
5.1.4 Limits of Physiological Decontamination 70
5.1.5 Limits between Irritation and Burn 71
5.1.6 Eye Burns 72
5.2 Pathophysiology of Eye Burns1 72
5.2.1 Types of Burns and Eye Irritation 72
5.2.2 Mechanisms of Corneal Burns 73
5.2.2.1 Contact Mechanisms 73
5.2.2.2 Thermal Contact 74
Particles 74
Hot Fluids 74
Steam 74
Liquid Metals 74
Cold Gazes 74
5.2.2.3 Eye Burns with Chemically Active Foreign Bodies 74
5.2.2.4 Eye Burns with Chemically Reactive Fluids 75
Alkali 75
Acids 75
Peroxides 75
Hydrofluoric Acid 77
Detergents/Solvents 77
5.2.3 Influence of Osmolarity 77
5.2.4 Penetration Characteristics 78
5.2.5 Cellular Survival 78
5.2.6 Release of Inflammatory Mediators 79
References 81
6: Rinsing Therapy of Eye Burns 84
6.1 Important 84
6.2 Mechanisms of Diffusion in Rinsing Therapy 85
6.3 Osmolar Effects in Rinsing Therapy 85
6.3.1 Types of Irrigation Fluids 89
6.4 Effect of Irrigation Fluids 89
6.5 High End Decontamination 93
6.5.1 Peroxides and Radicals Decontamination 93
6.5.2 Hydrofluoric Acid Decontamination 94
6.6 Side Effects of Rinsing Solutions in the Treatment of Eye Burns 97
6.7 Our Expectations 98
References 98
7: The Clinical of Ocular Burns 100
7.1 Few Reminders 100
7.1.1 Anatomy Reminder 100
7.1.2 Physiology Reminder 100
7.2 Immediate Clinical of the Ocular Chemical Burn 101
7.2.1 Initial and Essential Clinical Signs of the Ocular Chemical Burns 101
7.2.1.1 The Perilimbal (or Conjunctival) Ischemia 101
7.2.1.2 Ulcer of the Cornea 102
7.2.1.3 Edema of the Cornea 103
7.2.2 Roper Hall’s Prognostic Classification of the Chemical Eye Burns 104
7.2.3 The Initial Sketch 105
7.2.4 Other Initial Signs of Chemical Eye Burn 105
7.2.4.1 Signs of Alteration of the Conjunctiva 105
7.2.4.2 Signs of Intraocular Lesions 105
7.2.4.3 Extraocular Signs 106
7.3 Clinical Examination of the Evolution of Chemical Eye Burns 106
7.3.1 Benign Ocular Burns 106
7.3.2 Serious Ocular Burns 106
7.3.2.1 Complications on the Ocular Surface 106
Corneal Nonhealing 106
Other Complications on the Ocular Surface 107
7.3.2.2 Endocular Complication 108
Bibliography 108
8: Surgical Therapeutic of Ocular Burns 110
8.1 Surgical Treatment of Ocular Burns 110
8.1.1 Debridement/Excision of the Necrotic Tissues 110
8.1.2 Prevention of the Formation of Symblepharons 110
8.1.3 Tenon’s Plastics 110
8.1.4 The Conjunctival Transplantation 111
8.1.5 Transplantation of Buccal and Nasal Mucosa 111
8.1.6 The Transplantation of Limbus 112
8.1.6.1 Exeresis of the Conjunctival Pannus 112
8.1.6.2 The Limbus Autograft 112
8.1.6.3 The Limbus Allograft 113
8.1.7 The Transplantation of Amniotic Membrane 113
8.1.8 Keratoplasties 113
8.1.8.1 Big Diameter Transfixion Keratoplasty 113
8.1.8.2 The Usual Diameter Transfixion Keratoplasty 114
8.1.8.3 The Deep Lamellar Keratoplasty 115
8.1.8.4 The Big Diameter Lamellar Keratoplasty 115
8.1.8.5 The Keratoplasty with Architectonic Goal 116
8.1.9 The Transplantation of Cultivated Limbal Epithelial Cells 116
8.1.10 Keratoprosthesis 116
8.2 Surgical Treatment of Eyelid Burns 116
8.2.1 Surgical Treatment in the Critical Phase 117
8.2.2 Surgical Treatment in the Sequelar Phase 117
8.3 Conclusion 117
References 117
9: Emergency Treatment 120
9.1 Characteristics and Consequences of Chemical Ocular Traumas 120
9.2 Chemical Emergency: A Race Against the Clock 120
9.3 Stakes in the Management of First Aid 121
9.3.1 In Occupational Environments 121
9.3.2 After an Accident on the Public Highway 122
9.3.3 Industrial Accidents 122
9.3.4 Attacks 122
9.3.5 Lack of Initial Care 122
9.4 Organizing the Emergency Chain 122
9.5 Treatment of Ocular Injury: The Importance of the Emergency Chain for Care 123
9.5.1 Emergency Chain Definition 123
9.5.2 Safety Obligations 123
9.5.3 The Specific Management of Chemical Injuries 124
9.6 Which Care Chain for Optimum Management of Chemical Eye Burns? 124
9.6.1 Immediate Care by “Nonspecialists” 124
9.6.2 Ophthalmological Management is Often Deferred 124
9.6.3 Practical Consequences for More Effective Management 125
9.6.3.1 Develop a Protocol Which Must Be Simple in Every Aspect 125
9.6.3.2 Training 125
9.6.3.3 Necessary Specialized Supervision 125
Index 126