Corneal Emergencies

Foreword
Preface
Preface
About the Editors
Contents
1: Anatomical, Pathophysiological, and Wound Healing Aspects in Corneal Emergencies
1.1 Introduction
1.2 Anatomical Considerations
1.3 Physiological Considerations
1.3.1 Epithelium
1.3.2 Stroma
1.3.3 Endothelium
1.4 Corneal Wound Healing
1.4.1 Epithelial Healing
1.4.1.1 Cellular Events
1.4.1.2 Molecular Events
1.4.2 Epithelial Wound Healing Response
1.4.2.1 Corneal Abrasion
1.4.2.2 Corneal Ulcer
1.4.2.3 Thermal Burns
1.4.2.4 Stevens–Johnson Syndrome
1.4.2.5 Chemical Injuries
1.4.2.6 Contact Lens Wear
1.4.3 Stromal Wound Healing
1.4.3.1 Cellular Events
1.4.3.2 Molecular Events
1.4.4 Stromal Wound Healing Response
1.4.4.1 Corneal Ulcer
1.4.4.2 Peripheral Ulcerative Keratitis (PUK)
1.4.4.3 Corneal Lacerations
1.4.4.4 Refractive Surgeries
1.4.4.5 Acute Chemical Injuries
1.4.4.6 Advanced Corneal Ectasia
1.4.4.7 Corneal Transplantation
1.4.4.8 Corneal Graft Rejection
1.4.5 Endothelial Wound Healing
1.4.5.1 Cellular Events
1.4.5.2 Molecular Events
1.4.6 Endothelial Wound Healing Response
1.4.6.1 Corneal Perforation
1.4.6.2 Refractive Surgery
1.4.6.3 Contact Lens Associated Corneal Edema
1.4.6.4 Advanced Corneal Ectasia
1.5 Limbus: Anatomical Considerations and Response to Wound Healing
1.5.1 Stevens–Johnson Syndrome
1.5.2 PUK
1.6 Corneal Innervation and Applied Aspects
1.7 Corneal Vascular System
1.8 Conclusion
References
2: Epidemiology and Risk Factors
2.1 Introduction
2.2 Minor Corneal Emergencies
2.2.1 Epidemiology
2.2.2 Risk Factors
2.3 Corneal Lacerations and Penetrating Injuries
2.3.1 Epidemiology
2.3.2 Risk Factors
2.4 Microbial Keratitis
2.4.1 Epidemiology
2.4.2 Risk Factors
2.5 Corneal Perforations
2.5.1 Epidemiology
2.5.2 Risk Factors
2.6 Acute Chemical Injuries
2.6.1 Epidemiology
2.6.2 Risk Factors
2.7 Emergencies Associated with Corneal Transplantation
2.7.1 Epidemiology
2.7.2 Risk Factor
2.8 Acute Graft Rejection
2.8.1 Epidemiology
2.8.2 Risk Factor
2.9 Post-surgical Corneal Wound Dehiscence
2.9.1 Epidemiology
2.9.2 Risk Factors
2.10 Contact Lens-Associated Corneal Emergency
2.10.1 Epidemiology
2.10.2 Risk Factor
2.11 Peripheral Ulcerative Keratitis
2.11.1 Epidemiology
2.11.2 Risk Factors
2.12 Emergency in Advanced Corneal Ectasia
2.12.1 Epidemiology
2.12.2 Risk Factor
2.13 Stevens–Johnson Syndrome
2.13.1 Epidemiology
2.13.2 Risk Factor
2.14 Vitamin A Deficiency and Xerophthalmia
2.14.1 Epidemiology
2.14.2 Risk Factors
2.15 Conclusion
References
3: Requisites of Cornea Clinic and Casualty Services to Manage Corneal Emergencies
3.1 Introduction
3.2 Clinic Setup
3.2.1 Equipment and Manpower
3.2.2 Consumables
3.2.3 Drugs
3.2.4 Instruments
3.3 Procedures Performed in OPD
3.3.1 Corneal Scraping
3.3.2 Corneal Gluing
3.3.3 Saline Wash in Acute Chemical Injury
3.3.4 Corneal Foreign Body Removal
3.3.5 Corneal Suture Removal
3.4 Conclusion
References
4: Diagnostic and Therapeutic Approach in Management of Corneal Emergencies
4.1 Introduction
4.2 History Taking
4.2.1 Assess Systemic Status
4.2.2 Determine the Mechanism of Injury
4.2.3 Symptoms
4.2.4 Medical History
4.2.5 Treatment History
4.3 Clinical Examination
4.3.1 Visual Acuity
4.3.2 Systemic Examination
4.3.3 External Examination
4.3.4 Slit Lamp Examination
4.3.4.1 Lids
4.3.4.2 Conjunctiva
4.3.4.3 Sclera
4.3.4.4 Cornea
Epithelium
Stroma
Descemet Membrane
Endothelium
4.3.4.5 Anterior Chamber (AC)
4.3.4.6 Iris
4.3.4.7 Lens
4.3.4.8 Intraocular Pressure (IOP)
4.3.4.9 Fundus
4.4 Diagnostic Approach
4.4.1 Fluorescein Stain
4.4.2 X-Ray
4.4.3 CT-Scan
4.4.4 MRI
4.4.5 B-Scan
4.4.6 Ultrasound Biomicroscopy (UBM)
4.4.7 Anterior Segment OCT (AS-OCT)
4.4.8 In-Vivo Confocal Microscopy (IVCM)
4.4.9 OCT Angiography (OCTA)
4.4.10 Corneal Topography
4.4.11 Microbiology
4.5 Therapeutic Approach
4.5.1 Acute Chemical Injury
4.5.2 Stevens–Johnson Syndrome
4.5.3 Corneal Ulcer
4.5.4 Peripheral Ulcerative Keratitis
4.5.5 Contact Lens-Related Emergencies
4.5.6 Corneal Hydrops
4.5.7 Post-PK Emergencies
4.5.8 Post-refractive Surgery Corneal Emergencies
4.5.9 Corneal Perforation/Laceration
4.6 Conclusion
References
5: Minor Corneal Emergencies
5.1 Introduction
5.2 Corneal Abrasions
5.2.1 Aetiology
5.2.2 Clinical Features
5.2.3 Complications
5.2.4 Examination and Investigations
5.2.5 Management
5.3 Corneal Foreign Body
5.3.1 Clinical Features
5.3.2 Complications
5.3.3 Investigations
5.3.4 Management
5.4 Recurrent Corneal Erosions
5.4.1 Aetiology
5.4.2 Aetiological Types
5.4.3 Clinical Features
5.4.4 Management
5.5 Photokeratitis
5.5.1 Aetiology
5.5.2 Clinical Features
5.5.3 Management
5.6 Minor Chemical Injury
5.6.1 Clinical Features
5.6.2 Management
5.7 Corneal Infections
5.7.1 Viral Keratitis
5.7.1.1 Clinical Features
5.7.1.2 Management
5.8 Miscellaneous
5.8.1 Contact Lens-Related Minor Emergencies
5.8.1.1 Risk Factors
5.8.1.2 Clinical Features
5.8.1.3 Investigations
5.8.1.4 Management
5.8.2 Neurotrophic Keratitis
5.8.2.1 Aetiology
5.8.2.2 Clinical Features
5.8.2.3 Management
5.8.3 Exposure Keratopathy
5.8.3.1 Aetiology
5.8.3.2 Clinical Features
5.8.3.3 Management
5.8.4 Ruptured Corneal Bulla
5.8.4.1 Aetiology
5.8.4.2 Clinical Features
5.8.4.3 Management
5.9 Conclusion
References
6: Corneal Laceration and Penetrating Injuries
6.1 Epidemiology
6.1.1 Age and Sex
6.1.2 Socioeconomic Background
6.2 Betts Classification and Nomenclature
6.3 History Taking and Clinical Presentation
6.4 Ocular Investigations
6.4.1 Ultrasonography
6.4.2 X-Ray
6.4.3 CT Scan
6.4.4 Special Attention to Be Given to Following Points While Reading Radiograph/CT Scan
6.5 Treatment
6.5.1 Corneal Abrasion
6.5.2 Corneal Laceration Management
6.5.2.1 General Principles
6.5.2.2 Simple Corneal Laceration
6.5.2.3 Simple Full-Thickness Laceration Less Than 2 mm
6.5.2.4 Simple Full-Thickness Laceration More Than 2 mm
6.6 Basic Principles of Corneal Laceration Suturing
6.6.1 Preferred Anaesthesia
6.6.2 Preferred Suture Material
6.6.3 ‘No Touch’ Technique
6.6.4 Astigmatism and Suturing
6.6.5 Suturing Large Wound with Stellate or Branching Pattern
6.7 Complicated Corneal Lacerations
6.7.1 Corneal Laceration with Uveal Incarceration or Prolapse
6.7.2 Corneal Laceration Along with Limbus or Scleral Involvement
6.7.3 Corneal Laceration with Traumatic Cataract
6.7.3.1 Simultaneous Corneal Tear Repair with Cataract Extraction
6.7.4 Corneal Laceration with Endophthalmitis
6.7.5 Treatment of Associated Cyclodialysis
6.8 Postoperative Management
6.9 Management of Astigmatism After Corneal Laceration Repair
References
7: Emergencies in Microbial Keratitis
7.1 Introduction
7.2 Incidence
7.3 Aetiology
7.4 Approach to Diagnosis
7.4.1 History
7.4.2 Clinical Examination
7.4.3 Microbiological Evaluation
7.4.4 Response to Treatment
7.4.5 When to Refer?
7.5 Bacterial Keratitis
7.5.1 Diagnostic Differentiators
7.5.1.1 Staphylococci
7.5.1.2 Streptococci
7.5.1.3 Pseudomonas
7.5.2 Management
7.6 HSV Keratitis
7.6.1 Diagnostic Differentiators
7.6.1.1 HSV Epithelial Keratitis
7.6.1.2 Marginal Ulcer of HSV
7.6.1.3 Stromal Keratitis
Necrotising Stromal Keratitis
Immune Stromal (Interstitial) Keratitis
7.6.1.4 HSV Endotheliitis
7.6.1.5 Neurotrophic Ulcers
7.7 Fungal Keratitis
7.7.1 Diagnostic Differentiators
7.7.2 Treatment
7.8 Acanthamoeba Keratitis
7.8.1 Diagnostic Differentiators
7.8.2 Treatment
7.9 Pythium Keratitis
7.9.1 Diagnostic Differentiators
7.9.2 Diagnosis
7.9.3 Treatment
7.10 Surgical Management
7.11 Corneal Emergencies Associated with Microbial Keratitis and Their Management (Table 7.1)
7.11.1 Penetrating Trauma with/Without Foreign Body
7.11.2 Descemetocele and Corneal Melt or Perforation
7.11.3 Scleritis
7.11.4 Endophthalmitis
7.12 Conclusion
References
8: Corneal Perforations
8.1 Introduction
8.2 Pathophysiology of Corneal Perforations
8.3 Clinical History
8.4 Symptoms
8.5 Signs
8.6 Workup
8.7 Causes of Corneal Perforations
8.7.1 Infectious Corneal Perforations
8.7.1.1 Bacterial Keratitis
8.7.1.2 Fungal Keratitis
8.7.1.3 Viral Keratitis
8.7.2 Non-Infectious Corneal Perforations
8.7.2.1 Autoimmune Conditions
8.7.2.2 Ocular Surface Disease
8.7.2.3 Corneal Degenerations or Ectasias
8.8 Management of Corneal Perforations
8.8.1 Non-surgical Treatment
8.8.1.1 Lubricating Treatments
Indication
Technique
8.8.1.2 Antimicrobials
Indication
Technique
8.8.1.3 Anti-collagenases
Indication
Technique
8.8.1.4 Aqueous Suppressants
Indication
Technique
8.8.1.5 Anti-Inflammatories
Indication
Technique
8.8.1.6 Bandage Contact Lens
8.8.2 Surgical Treatment
8.8.2.1 Corneal Gluing
Indication
Technique
Outcomes
8.8.2.2 Tenon’s Patch Graft
Technique
8.8.2.3 Keratoplasty
Indication
Technique
Outcomes
8.8.2.4 Amniotic Membranes
Indication
Technique and Outcomes
8.8.2.5 Conjunctival Flaps
References
9: Emergencies in Corneal Refractive Surgeries
9.1 Introduction
9.2 Intraoperative Corneal Emergencies
9.2.1 Corneal Emergencies Related to Microkeratome-Flap Creation
9.2.1.1 Incidence
9.2.1.2 Risk Factors
9.2.1.3 Diagnosis
9.2.1.4 Treatment
9.2.1.5 Prevention
9.2.2 Corneal Emergencies Related to Femtosecond-Laser Assisted Flap
9.2.2.1 Suction Loss
Incidence
Risk Factors
Diagnosis
Treatment
Prevention
9.2.2.2 Vertical Gas Breakthrough
Incidence
Risk Factors
Diagnosis
Management
Prevention
9.2.2.3 Flap Tears
Incidence
Risk Factors
Diagnosis
Treatment
Prevention
9.2.3 Corneal Perforation During Excimer Laser Ablation
9.2.3.1 Risk Factors
9.2.3.2 Treatment
9.2.3.3 Prevention
9.2.4 Lenticule Extraction Related Corneal Emergencies
9.2.4.1 Suction Loss
Incidence
Risk Factors
Diagnosis
Treatment
Prevention
9.2.4.2 Lenticule Mis-Dissection and Cap-Lenticular Adhesion
Incidence
Risk Factors
Diagnosis
Treatment
Prevention
9.2.5 Corneal Perforation During Intracorneal Ring Segments Implantation
9.2.5.1 Incidence
9.2.5.2 Risk Factors
9.2.5.3 Diagnosis
9.2.5.4 Treatment
9.2.5.5 Prevention
9.2.6 Corneal Emergencies Related to Radial Keratotomy
9.3 Postoperative Corneal Emergencies
9.3.1 Infectious Keratitis
9.3.1.1 Incidence
9.3.1.2 Causative Organisms
9.3.1.3 Risk Factors
9.3.1.4 Diagnosis
9.3.1.5 Treatment
9.3.1.6 Prevention
9.3.2 Rupture or Dehiscence of Radial Keratotomy Incisions
9.3.2.1 Risk Factors
9.3.2.2 Diagnosis
9.3.2.3 Management
9.3.2.4 Prevention
9.3.3 Intracorneal Ring Segment Extrusion and Corneal Melt
9.3.3.1 Incidence
9.3.3.2 Risk Factors
9.3.3.3 Treatment
9.3.3.4 Prevention
9.3.4 Acute Hydrops
9.3.4.1 Risk Factors
9.3.4.2 Diagnosis
9.3.4.3 Management
9.3.4.4 Prevention
9.3.5 Acute Corneal Haze After Photorefractive Keratectomy
9.3.5.1 Risk Factors
9.3.5.2 Diagnosis
9.3.5.3 Treatment
9.3.5.4 Prevention
9.3.6 Flap Macrostriae and Flap Dislocation
9.3.6.1 Incidence
9.3.6.2 Risk Factors
9.3.6.3 Diagnosis
9.3.6.4 Treatment
9.3.6.5 Prevention
9.3.7 Diffuse Lamellar Keratitis
9.3.7.1 Incidence
9.3.7.2 Risk Factors
9.3.7.3 Diagnosis
9.3.7.4 Treatment
9.3.7.5 Prevention
9.3.8 Central Toxic Keratopathy
9.3.8.1 Incidence
9.3.8.2 Diagnosis
9.3.8.3 Treatment
9.3.9 Pressure-Induced Intralamellar Stromal Keratitis
9.3.9.1 Diagnosis
9.3.9.2 Treatment
9.4 Conclusion
References
10: Acute Chemical Injuries of the Cornea
10.1 Introduction
10.2 Causative Agents of Ocular Chemical Injury
10.2.1 Classification of Common Agents Responsible for Causing Ocular Chemical Injuries
10.2.1.1 Vesicants
10.2.1.2 Lacrimatory Agents
10.2.1.3 Plant-Based Toxins
10.2.1.4 Other Common Agents Responsible for Ocular Chemical Injuries
10.3 Pathophysiology of a Corrosive Injury
10.3.1 Rise in Intraocular Pressure (IOP)
10.3.2 Inflammatory Process
10.3.3 Fall in the Aqueous Ascorbate Levels
10.4 Clinical History
10.5 Immediate Treatment and Transfer
10.5.1 Treatment at the Injury Site
10.5.2 Treatment in Ophthalmic Emergency
10.5.2.1 Choice of Fluid and Duration of Irrigation
10.5.2.2 Aqueous Humor Replacement
10.6 Clinical Examination and Classification of Chemical Injuries
10.7 Phases of Chemical Injury
10.8 Treatment
10.8.1 Acute and Early Reparative Treatment
10.8.1.1 Broad-Spectrum Topical Antibiotics
10.8.1.2 Artificial Lubricants and Cycloplegics
10.8.1.3 Oral and Topical Sodium Ascorbate (10%)
10.8.1.4 Corticosteroids
10.8.1.5 Oral Tetracyclines and Topical Citrate
10.8.1.6 Ocular Hypotensive Agents
10.8.1.7 Blood Derived Topical Agents
10.8.2 Surgical Treatment in the Acute Phase
10.8.2.1 Amniotic Membrane Transplantation (AMT)
10.8.2.2 Tenonplasty
10.8.2.3 Glued-On Contact Lens
10.8.3 Treatment in the Intermediate Stage
10.8.4 Chronic Sequelae and Treatment
10.8.4.1 Limbal Stem Cell Transplant
10.8.4.2 Keratoplasty
10.8.5 Treatment of the End-Stage Disease
10.8.5.1 Keratoprosthesis
10.8.5.2 Enucleation or Evisceration
10.8.6 Experimental Treatment Modalities
References
11: Emergencies Associated with Corneal Transplantation
11.1 Intraoperative Emergencies
11.1.1 Host Related
11.1.1.1 Posterior Capsule Tear With or Without Vitreous Loss
Presentation and Diagnosis
Management
11.1.1.2 Suprachoroidal. Hemorrhage
Presentation and Diagnosis
Management
Prevention
11.1.1.3 Descemet Membrane Perforation
Incidence and Risk Factors
Presentation
Management
Outcome and Prevention
11.1.2 Donor Related
11.2 Postoperative Emergencies
11.2.1 Complications Common to all Keratoplasties
11.2.1.1 Anterior Segment Inflammation
Risk Factors
Types
Management
11.2.1.2 Wound Leak
11.2.1.3 Glaucoma
Presentation
Management
11.2.1.4 Suture Related Complications
11.2.1.5 Persistent Epithelial Defect
Risk Factors
Management
Outcome
11.2.1.6 Posterior Segment-Related Complications
Endophthalmitis
Causative Organism
Risk Factors
Presentation and Diagnosis
Management
Prevention
Choroidal Detachment
Retinal Detachment
Cystoid Macular Edema
11.2.1.7 Graft Infection
Risk Factors
Management
Outcome
11.2.1.8 Graft Rejection
Incidence
Risk Factors
Types
Management
Outcome
11.2.1.9 Graft Failure
Management
11.2.2 Complications Specific to Lamellar Keratoplasties
11.2.2.1 Interface-Related Problems
Interface Fluid
Interface Bleed
Interface Infection
Epithelial Ingrowth
11.2.2.2 Graft Detachment
11.3 Conclusion
References
12: Acute Graft Rejection
12.1 Introduction
12.2 Incidence
12.3 Risk Factors for Corneal Graft Rejection
12.3.1 Donor Characteristics
12.3.2 Host Characteristics
12.3.2.1 Host Bed Vascularisation
12.3.2.2 Failed Grafts
12.3.2.3 Pre-Existing Disease
12.3.3 Technical Factors
12.3.4 Other Factors
12.3.5 Low Risk Penetrating Keratoplasty
12.4 Pathogenesis
12.5 Clinical Presentation
12.5.1 Symptoms
12.5.2 Signs
12.5.2.1 Epithelial Rejection
12.5.2.2 Subepithelial Rejection
12.5.2.3 Stromal Rejection
12.5.2.4 Endothelial Rejection
12.5.3 Differential Diagnosis
12.6 Treatment
12.6.1 Response to Treatment
12.7 Prophylaxis
12.8 Prevention
12.9 Summary
References
13: Post-Surgical Corneal Wound Dehiscence
13.1 Introduction
13.2 Corneal Wound Healing
13.3 Wound Dehiscence Following Corneal Surgeries
13.3.1 Penetrating Keratoplasty
13.3.1.1 Clinical Features
13.3.1.2 Types of Graft Dehiscence
13.3.1.3 Predisposing Factors
13.3.1.4 Management
13.3.1.5 Outcomes
13.3.2 Lamellar Keratoplasty
13.3.3 Repaired Corneal Perforation
13.3.3.1 Management
13.3.4 Cataract Surgery
13.3.4.1 Predisposing Factors and Preventive Measures
13.3.4.2 Management
13.3.5 Refractive Surgery
13.3.5.1 Risk Factors and Preventive Measures
13.3.5.2 Management
13.4 Conclusion
References
14: Contact Lens-Associated Emergencies
14.1 Introduction
14.2 Pathogenesis of Contact Lens-Related Emergencies
14.2.1 Hypoxia
14.2.2 Mechanical Factors
14.2.3 Immunological Factors
14.2.4 Tear Film Abnormality
14.3 Classification
14.4 Contact Lens Associated Microbial Keratitis
14.4.1 Acanthamoeba Keratitis
14.4.2 Pseudomonas Keratitis
14.4.3 Fungal Keratitis
14.5 Corneal Edema
14.6 Contact Lens-Related Peripheral Ulcer (CLPU)
14.7 Contact Lens Adhesion Phenomenon or Binding
14.7.1 Pathogenesis
14.7.2 Clinical Features
14.7.3 Treatment
14.8 Sterile Corneal Infiltrates
14.9 Contact Lens-Induced Acute Red Eye-CLARE
14.9.1 Clinical Features
14.9.2 Treatment
14.10 Corneal Abrasions
14.11 Conclusion
References
15: Peripheral Ulcerative Keratitis
15.1 Introduction
15.2 Clinical Presentation
15.2.1 Symptoms
15.2.2 Clinical Features
15.3 Etiology and Pathogenesis
15.3.1 Etiology
15.3.1.1 Mooren’s Ulcer
15.3.1.2 Collagen Vascular Diseases
15.3.1.3 Infectious Causes
15.3.2 Pathogenesis
15.3.2.1 Immune Complexes
15.3.2.2 Matrix Metalloproteinases (MMP)
15.4 Management
15.4.1 Medical Management
15.4.1.1 Infectious Causes
15.4.1.2 Mooren’s Ulcer
15.4.1.3 With Associated Systemic Disease
15.4.2 Surgical Management
15.4.2.1 Conjunctival Resection with Tissue Adhesive and Bandage Contact Lens Application
15.4.2.2 Management of Perforations <2 mm
15.4.2.3 Large Perforations
Multi-Layered AMG
Tenon’s Patch Graft
Patch Graft
Keratoplasty
15.5 Differential Diagnosis
15.6 Conclusion
References
16: Emergencies Associated with Advanced Corneal Ectasias
16.1 Introduction
16.2 Acute Corneal Hydrops
16.2.1 Introduction
16.2.2 Predisposing Factors
16.2.3 Pathogenesis
16.2.4 Clinical Characteristics
16.2.5 Investigations
16.2.6 Management
16.2.6.1 Conservative Approach
16.2.6.2 Intracameral Air/Gas Injection
16.2.6.3 Compressive Sutures
16.2.6.4 PKP
16.2.6.5 Cyanoacrylate Tissue Adhesive with BCL
16.2.6.6 AMT with Cauterization
16.2.6.7 ASOCT Guided Intrastromal Fluid Drainage with Air Tamponade
16.2.6.8 Microscope-OCT-Guided Puncture and Intrastromal Fluid Pockets Drainage with Gas Tamponade
16.2.7 Outcome
16.2.8 Acute Corneal Hydrops with Microbial Keratitis
16.2.8.1 Diagnosis
16.2.8.2 Treatment
16.3 Corneal Perforation
16.3.1 Introduction
16.3.2 Clinical Features
16.3.3 Management
16.3.3.1 Cyanoacrylate Tissue Adhesive with Bandage Contact Lens (BCL)
16.3.3.2 Patch Graft
16.3.3.3 Lamellar Transplant
16.3.3.4 Penetrating Keratoplasty
16.4 Rehabilitative Procedures
16.4.1 Nonsurgical Management
16.4.1.1 Optical Correction
16.4.1.2 Contact Lenses
16.4.2 Surgical Management
16.4.2.1 Intrastromal Corneal Ring Segment (ICRS)
16.4.2.2 Large-Diameter PKP
16.4.2.3 Lamellar Keratoplasty (LK)
16.4.2.4 LK with PKP
16.4.2.5 Simultaneous Peripheral Crescentic LK and Central PKP
16.4.2.6 Tectonic LK Followed by Secondary PKP
16.4.2.7 Tuck-in Lamellar Keratoplasty (TILK)
16.4.2.8 Wedge Resection
16.5 Conclusion
16.6 Recommendations
References
17: Stevens–Johnson Syndrome
17.1 History and Classification
17.2 Etiologies
17.3 Pathogenesis
17.4 Clinical Features
17.4.1 Systemic
17.4.2 Acute Ocular
17.5 Medical Management
17.5.1 Systemic Therapy
17.5.2 Ocular Examination and Classification
17.5.3 Acute Topical Therapy
17.5.3.1 Ocular Lubricants
17.5.3.2 Topical Anti-Inflammatories
17.5.3.3 Topical Antibiotics
17.5.3.4 Prokera and Symblepharon Preventative Measures
17.6 Acute Surgical Management
17.6.1 Background
17.6.2 Amniotic Membrane Transplantation
17.6.2.1 Technique
17.6.2.2 Postoperative Management
17.6.2.3 Repeat AMT Applications
17.7 Chronic Management
17.7.1 Ocular Surface
17.7.2 Eyelid and Forniceal Management
17.8 Conclusions
References
18: Corneal Emergencies Associated with Other Intraocular Surgeries
18.1 Introduction
18.2 Corneal Emergencies in Cataract Surgery
18.2.1 Descemet Membrane Tears and Detachment
18.2.1.1 Predisposing Factors
18.2.1.2 Diagnosis
18.2.1.3 Management
18.2.1.4 Prevention
18.2.2 Acute Corneal Clouding
18.2.2.1 Predisposing Factors
18.2.2.2 Diagnosis
18.2.2.3 Management
18.2.2.4 Prevention
18.2.3 Corneal Endothelial Toxicity and Toxic Anterior Segment Syndrome
18.2.3.1 Predisposing Factors
18.2.3.2 Diagnosis
18.2.3.3 Management
18.2.3.4 Prevention
18.2.4 Clear-Corneal Incision Related Complications
18.2.4.1 Predisposing Factors
18.2.4.2 Diagnosis
18.2.4.3 Management
18.2.4.4 Prevention
18.3 Corneal Emergencies in Glaucoma Surgeries
18.3.1 Descemet Membrane Detachment
18.3.1.1 Predisposing Factors
18.3.1.2 Diagnosis
18.3.1.3 Management
18.3.1.4 Prevention
18.3.2 Tube Migration with Tube-Corneal Touch
18.3.2.1 Predisposing Factors
18.3.2.2 Diagnosis
18.3.2.3 Management
18.3.2.4 Prevention
18.3.3 Blebitis and Keratitis
18.3.3.1 Pathogens
18.3.3.2 Predisposing Factors
18.3.3.3 Diagnosis
18.3.3.4 Management
18.3.3.5 Prevention
18.4 Corneal Emergencies in Strabismus Surgeries
18.4.1 Anterior Segment Ischemia
18.4.1.1 Predisposing Factors
18.4.1.2 Diagnosis
18.4.1.3 Management
18.4.1.4 Prevention
18.5 Corneal Emergencies in Ocular Surface, Lid and Orbital Surgeries
18.5.1 Corneal Perforation
18.5.1.1 Predisposing Factors
18.5.1.2 Management
18.5.1.3 Prevention
18.6 Corneal Emergencies in Vitreoretinal Surgeries
18.6.1 Corneal Clouding
18.6.1.1 Predisposing Factors
18.6.1.2 Diagnosis
18.6.1.3 Management
18.6.1.4 Prevention
18.6.2 Wound Leak
18.6.2.1 Predisposing Factors
18.6.2.2 Diagnosis
18.6.2.3 Management
18.6.2.4 Prevention
18.7 Conclusion
References
19: Keratomalacia
19.1 Introduction
19.2 Clinical Features
19.2.1 Conjunctival Xerosis (X1A) and Bitot’s Spots (X1B)
19.2.1.1 Conjunctival Xerosis
19.2.1.2 Bitot’s Spot
19.2.2 Corneal Xerosis (X2)
19.2.3 Corneal Ulceration/Keratomalacia (X3A, X3B)
19.2.4 Corneal Scars (XS)
19.3 Keratomalacia
19.3.1 Pathogenesis
19.3.2 Associated Corneal Emergencies
19.3.2.1 Corneal Ulceration
19.3.2.2 Corneal Perforation
19.3.2.3 Secondary Keratitis
19.3.2.4 Phthisis Bulbi
19.3.3 Treatment
19.3.3.1 Adjunctive Modalities
19.3.3.2 Medical Status and Diet
19.3.3.3 Surgical Management
19.4 Prevention
19.5 Conclusion
References
20: Public Awareness, Preventive and Medicolegal Aspects in Corneal Emergencies
20.1 Introduction
20.2 Awareness
20.2.1 Traumatic Corneal Emergencies
20.2.1.1 Preventive Measures
20.2.1.2 Information, Education, and Communication (IEC)
20.2.1.3 Legislation
20.2.2 Infectious Keratitis
20.2.2.1 Preventive Measures
20.2.2.2 IEC
20.2.3 Keratomalacia
20.2.4 Corneal Refractive Surgeries
20.3 Medicolegal Implications
20.3.1 Approach to Deal with Emergency Cases
20.3.2 Clinical Examination
20.3.3 Record Keeping
20.3.4 Informed and Documented Consent
20.4 Conclusion
References
Index