- •The Sclera
- •Preface
- •Contents
- •1.1 Introduction
- •1.2 Development of the Sclera
- •1.2.1.1 First Week
- •1.2.1.2 Second Week
- •1.2.1.3 Third Week
- •1.2.1.4 Fourth Week
- •1.2.1.5 Fifth Week
- •1.2.1.6 Sixth Week
- •1.2.1.7 Seventh Week
- •1.2.1.8 Ninth Week
- •1.2.1.9 Tenth Week
- •1.2.1.10 Thirteenth Week
- •1.2.1.11 Sixteenth Week
- •1.2.1.12 Twenty-Fourth Week
- •1.2.2.1 Collagens
- •1.2.2.2 Proteoglycans
- •1.2.2.3 Glycoproteins
- •1.3 Anatomy
- •1.3.1 Gross and Microscopic Anatomy
- •1.3.1.1 Scleral Foramina
- •Anterior Scleral Foramen
- •Posterior Scleral Foramen
- •1.3.1.2 Layers of the Sclera
- •Episclera
- •Scleral Stroma
- •Lamina Fusca
- •1.3.1.3 Blood Supply and Emissary Canals
- •Vascular Distribution
- •Circulatory Dynamics
- •1.3.1.4 Nerve Supply
- •1.3.2 Ultramicroscopic Anatomy
- •1.3.2.1 Sclera
- •1.3.2.2 Vessels
- •1.4 Biochemistry
- •1.5 Immunohistochemistry
- •1.6 Biomechanics
- •1.7 Molecular Structure
- •1.7.1 Collagen
- •1.7.2 Elastin
- •1.7.3 Proteoglycans
- •1.7.4 Glycoproteins
- •1.7.6 Fibroblast Growth Regulation
- •1.8 Summary
- •References
- •2.1 General Immune Response Considerations
- •2.1.1 Components of the Adaptive Immune Response
- •2.1.1.1 Lymphocytes
- •T Lymphocytes
- •B Lymphocytes
- •Third-Population Lymphocytes or Null Lymphocytes
- •2.1.1.2 Monocytes/Macrophages
- •Phagocytosis
- •Antigen-Presenting Cells
- •2.1.1.3 Polymorphonuclear Granulocytes
- •Neutrophils
- •Eosinophils
- •Basophils/Mast Cells
- •2.1.1.4 Platelets
- •2.1.2 Immunoregulation
- •2.1.2.1 Major Histocompatibility Complex
- •2.1.2.2 Humoral Mechanisms: Antibodies
- •2.1.2.3 Cellular Mechanisms
- •2.1.2.4 Summary
- •2.1.3 Abnormalities of the Immune Response
- •2.1.3.1 Hypersensitivity Reactions
- •Type III Hypersensitivity Reactions
- •Systemic Immune Complex Disease
- •Local Immune Complex Disease (Arthus Reaction)
- •Type IV Hypersensitivity Reactions
- •2.1.3.2 Autoimmunity
- •Mechanisms of Autoimmunity
- •2.2 Connective Tissue and the Immune Response
- •2.2.1 Fibroblast Functions and the Immune Response
- •2.3 The Sclera and the Immune Response: Scleritis
- •2.3.1 Immune Characteristics of the Sclera
- •2.3.2 The Susceptible Host: Immunogenetics
- •2.3.3 Etiology
- •2.3.3.1 Exogenous Agents
- •Viruses
- •Mycobacteria
- •2.3.3.2 Endogenous Substances
- •Glycosaminoglycans
- •Collagen
- •2.3.4 Pathogenesis
- •2.4 Summary
- •References
- •3.1 Investigation of the Illness
- •3.1.1 Major Complaint and History of Present Illness
- •3.1.2 Past History
- •3.1.3 Family History
- •3.1.4 Past and Present Therapy History
- •3.1.5 Review of Systems
- •3.1.6 Systemic Examination
- •3.1.6.1 Head
- •3.1.6.2 Extremities
- •3.1.7 Ocular Examination
- •3.1.7.1 Episcleral and Scleral Examination
- •External Examination of the Eye in Daylight
- •Slit-Lamp Examination
- •Diffuse Illumination
- •Slit-Lamp Illumination
- •Red-Free Illumination
- •3.1.7.2 General Eye Examination
- •Visual Acuity
- •Pupils and Extraocular Muscles
- •Cornea
- •Anterior Uvea
- •Lens
- •Fundus
- •Intraocular Pressure
- •3.2 Diagnostic Tests
- •3.2.1 Blood Tests
- •3.2.1.1 Rheumatoid Factor
- •3.2.1.2 Anticyclic Citrullinated Peptide Antibodies
- •3.2.1.3 Antinuclear Antibodies
- •3.2.1.4 Antineutrophil Cytoplasmic Antibodies
- •3.2.1.5 Circulating Immune Complexes
- •Fluid-Phase Binding Assays
- •C1q-Binding Assay
- •Cell-Binding Assays
- •Raji Cell-Binding Assay
- •3.2.1.6 Complement
- •Quantitation Tests
- •Functional Tests
- •3.2.1.7 HLA Typing
- •3.2.1.8 Antibody Titers Against Infectious Organisms
- •3.2.1.9 Interferon-Gamma Release Assays (IGRAs)
- •3.2.2 Anterior Chamber Polymerase Chain Reaction Testing
- •3.2.3 Smears and Cultures
- •3.2.4 Skin Testing
- •3.2.5 Radiologic Studies
- •3.2.6.1 Anterior Segment Fluorescein Angiography Techniques
- •3.2.6.2 Normal Anterior Segment Fluorescein Angiography
- •Arterial Phase
- •Capillary Phase
- •Venous Phase
- •3.2.7 Anterior Segment Indocyanine Green Angiography
- •3.2.8 Other Imaging Studies
- •3.2.8.1 Ultrasonography
- •A-Scan Ultrasonography
- •B-Scan Ultrasonography
- •High-Frequency Ultrasound Biomicroscopy
- •3.2.8.2 Optical Coherence Tomography
- •3.2.8.3 Computer Tomography Scanning
- •3.2.8.4 Magnetic Resonance Imaging
- •3.3 Biopsy
- •3.3.1 Biopsy for Suspected Systemic Vasculitic Disease
- •3.4 Data Integration: Diagnosis
- •3.5 Therapeutic Plan
- •3.6 Summary
- •References
- •4.1 Episcleritis
- •4.1.1 Introduction
- •4.1.2 Patient Characteristics
- •4.1.3 Clinical Manifestations
- •4.1.4.1 Simple Episcleritis
- •4.1.4.2 Nodular Episcleritis
- •4.1.5 Associated Diseases
- •4.1.6 Precipitating Factors
- •4.2 Scleritis
- •4.2.1 Introduction
- •4.2.2 Patient Characteristics
- •4.2.3 Clinical Manifestations
- •4.2.4.1 Diffuse Anterior Scleritis
- •4.2.4.2 Nodular Anterior Scleritis
- •Differential Diagnosis
- •Paralimbic Scleromalacia
- •Senile Scleral Hyaline Plaques
- •4.2.4.5 Posterior Scleritis
- •Symptoms and Signs
- •Fundus Findings
- •Choroidal Folds
- •Subretinal Mass
- •Disk Edema and Macular Edema
- •Annular Ciliochoroidal Detachment and Serous Retinal Detachment
- •Associated Diseases
- •Complications
- •Ancillary Tests
- •Ultrasonography
- •Computerized Tomography (CT) Scanning
- •Fluorescein Angiography
- •Differential Diagnosis
- •Proptosis, Chemosis, Lid Swelling, and Limitation of Ocular Movements
- •Subretinal Mass
- •Choroidal Folds
- •Annular Ciliochoroidal Detachment and/or Serous Retinal Detachment
- •Disk and Macular Edema
- •4.2.5 Associated Diseases
- •4.2.6 Complications of Scleritis
- •4.2.6.1 Keratopathy
- •Peripheral Corneal Thinning
- •Stromal Keratitis
- •Peripheral Ulcerative Keratitis
- •4.2.6.2 Uveitis
- •4.2.6.3 Glaucoma
- •Angle-Closure Glaucoma
- •Open-Angle Glaucoma
- •Neovascular Glaucoma
- •4.2.6.4 Cataract
- •4.3 Summary
- •References
- •5: Pathology in Scleritis
- •5.1.3 Fibrinoid Necrosis
- •5.2.1 Pathology of Episcleritis
- •5.2.2 Pathology of Scleritis
- •5.2.2.1 Noninfectious Scleritis
- •Sclera
- •Cells
- •Extracellular Matrix
- •Vessels
- •Episclera
- •Conjunctiva
- •Iris, Ciliary Body, and Choroid
- •Cornea
- •Other Ocular Structures
- •Polyarteritis Nodosa
- •Allergic Granulomatous Angiitis (Churg–Strauss Syndrome)
- •Granulomatosis with Polyangiitis (Wegener)
- •Connective Tissue Diseases
- •Clinicopathological Correlates in Infectious Scleritis
- •Systemic Infections
- •Local Infections
- •5.3 Biopsy
- •5.3.1 Noninfectious Necrotizing Scleritis
- •5.3.2 Noninfectious Recurrent Diffuse or Nodular (Nonnecrotizing) Scleritis
- •5.3.3 Infectious Scleritis (Diffuse, Nodular, or Necrotizing Scleritis)
- •5.3.4 Biopsy Technique
- •5.4 Summary
- •References
- •6: Noninfectious Scleritis
- •6.1.1 Adult Rheumatoid Arthritis
- •6.1.1.1 Epidemiology
- •Signs and Symptoms of Joint Involvement
- •Extraarticular Systemic Manifestations
- •6.1.1.2 Systemic Manifestations
- •Onset
- •Tegument
- •Vessels
- •Lung
- •Heart
- •Nervous System
- •Lymph Nodes
- •Larynx
- •Felty’s Syndrome
- •Amyloidosis
- •Miscellaneous
- •6.1.1.3 Ocular Manifestations
- •Keratoconjunctivitis Sicca
- •Scleritis
- •Keratitis
- •Anterior Uveitis
- •Glaucoma
- •Cataract
- •Retinal, Choroidal, and Optic Nerve Changes
- •Motility Disturbances
- •Episcleritis
- •6.1.1.4 Laboratory Findings
- •Rheumatoid Factor
- •Antibodies to Cyclic Citrullinated Polypeptides
- •Complete Blood Count
- •Acute-Phase Reactants
- •Synovial Fluid Analysis
- •Circulating Immune Complexes
- •Antinuclear Antibodies
- •Complement
- •Cryoglobulins
- •Radiographic Evaluation
- •Diagnosis
- •6.1.2 Systemic Lupus Erythematosus
- •6.1.2.1 Epidemiology
- •6.1.2.2 Systemic Manifestations
- •Musculoskeletal
- •Tegument
- •Vessels
- •Kidney
- •Hearth
- •Nervous System
- •Lung
- •Miscellaneous
- •6.1.2.3 Ocular Involvement
- •Scleritis
- •Episcleritis
- •Other Ocular Findings
- •6.1.2.4 Laboratory Findings
- •6.1.2.5 Diagnosis
- •6.1.3 Ankylosing Spondylitis
- •6.1.3.1 Epidemiology
- •6.1.3.2 Systemic Manifestations
- •Articular Involvement
- •Extraarticular Systemic Manifestations
- •6.1.3.3 Ocular Manifestations
- •Anterior Uveitis
- •Scleritis
- •Episcleritis
- •6.1.3.5 Diagnosis
- •6.1.4 Reactive Arthritis (Reiter)
- •6.1.4.1 Epidemiology
- •6.1.4.2 Systemic Manifestations
- •Articular Involvement
- •Extraarticular Systemic Manifestations
- •6.1.4.3 Ocular Manifestations
- •Conjunctivitis
- •Anterior Uveitis
- •Scleritis
- •Episcleritis
- •Other Ocular Findings
- •6.1.4.4 Laboratory and Radiographic Findings
- •6.1.4.5 Diagnosis
- •6.1.5 Psoriatic Arthritis
- •6.1.5.1 Epidemiology
- •6.1.5.2 Systemic Manifestations
- •Skin and Articular Involvement
- •6.1.5.3 Ocular Manifestations
- •Scleritis
- •Episcleritis
- •6.1.5.4 Laboratory and Radiographic Findings
- •6.1.5.5 Diagnosis
- •6.1.6.1 Epidemiology
- •6.1.6.2 Systemic Manifestations
- •Gastrointestinal and Articular Manifestations
- •6.1.6.3 Ocular Manifestations
- •Anterior Uveitis
- •Scleritis
- •Episcleritis
- •Keratitis
- •6.1.6.4 Laboratory and Joint Radiologic Findings
- •6.1.6.5 Diagnosis
- •6.1.7 Relapsing Polychondritis
- •6.1.7.1 Epidemiology
- •6.1.7.2 Systemic Manifestations
- •6.1.7.3 Ocular Manifestations
- •Scleritis
- •Episcleritis
- •6.1.7.4 Laboratory Findings
- •6.1.7.5 Diagnosis
- •6.1.8 Polyarteritis Nodosa
- •6.1.8.1 Epidemiology
- •6.1.8.2 Systemic Manifestations
- •6.1.8.3 Ocular Manifestations
- •Scleritis
- •Episcleritis
- •6.1.8.4 Laboratory and Angiographic Findings
- •6.1.8.5 Diagnosis
- •6.1.9.1 Epidemiology
- •6.1.9.2 Systemic Manifestations
- •6.1.9.3 Ocular Manifestations
- •6.1.9.4 Laboratory Findings
- •6.1.9.5 Diagnosis
- •6.1.10 Granulomatosis with Polyangiitis (Wegener)
- •6.1.10.1 Epidemiology
- •6.1.10.2 Clinical Manifestations
- •6.1.10.3 Ocular Manifestations
- •Scleritis
- •Episcleritis
- •6.1.10.4 Laboratory Findings
- •6.1.10.5 Diagnosis
- •6.1.11 Adamantiades–Behçet’s Disease
- •6.1.11.1 Epidemiology
- •6.1.11.2 Systemic Manifestations
- •6.1.11.3 Ocular Manifestations
- •Scleritis
- •Episcleritis
- •6.1.11.4 Laboratory Findings
- •6.1.11.5 Diagnosis
- •6.1.12 Giant-Cell Arteritis
- •6.1.12.1 Epidemiology
- •6.1.12.2 Systemic Manifestations
- •6.1.12.3 Ocular Manifestations
- •Scleritis
- •6.1.12.4 Laboratory Findings
- •6.1.12.5 Diagnosis
- •6.1.13 Cogan’s Syndrome
- •6.1.13.1 Clinical Manifestations
- •Scleritis
- •Episcleritis
- •6.1.13.2 Laboratory Findings
- •6.2.1 Rosacea
- •6.3.1 Gout
- •6.5 Chemical Injury-Associated Scleritis
- •6.6 Summary
- •References
- •7: Infectious Scleritis
- •7.1 Bacterial Scleritis
- •7.1.1.1 Pathogenesis
- •7.1.1.2 Organisms
- •7.1.1.3 Management
- •7.1.1.4 Therapy
- •7.1.1.5 Prognosis
- •7.1.1.6 Our Experience
- •7.1.2 Mycobacterial Scleritis
- •7.1.2.1 Atypical Mycobacterial Disease
- •7.1.2.2 Tuberculosis
- •7.1.2.3 Leprosy
- •7.1.3 Spirochetal Scleritis
- •7.1.3.1 Syphilis
- •Epidemiology
- •Pathogenesis and Clinical Features
- •Scleritis and Episcleritis
- •Diagnosis
- •Therapy
- •7.1.3.2 Lyme Disease
- •Epidemiology
- •Pathogenesis and Clinical Features
- •Scleritis and Episcleritis
- •Diagnosis
- •7.1.3.3 Treatment
- •7.1.4 Chlamydial Scleritis
- •7.1.5 Actinomycetic Scleritis
- •7.1.5.1 Nocardiosis
- •7.2 Fungal Scleritis
- •7.2.1 Filamentous and Dimorphic Fungal Scleritis
- •7.2.1.1 Pathogenesis
- •7.2.1.2 Organisms
- •7.2.1.3 Management
- •7.2.1.4 Therapy
- •7.2.1.5 Our Experience
- •7.3 Viral Scleritis
- •7.3.1 Herpes Scleritis
- •7.3.1.1 Herpes Zoster Scleritis
- •Epidemiology
- •Pathogenesis
- •Clinical Features
- •Scleritis
- •Episcleritis
- •Diagnosis
- •Treatment
- •7.3.1.2 Herpes Simplex Scleritis
- •Epidemiology
- •Pathogenesis
- •Clinical Features
- •Scleritis
- •Episcleritis
- •Diagnosis
- •Therapy
- •Our Experience
- •7.3.2 Mumps Scleritis
- •7.4 Parasitic Scleritis
- •7.4.1 Protozoal Scleritis
- •7.4.1.1 Acanthamoeba
- •7.4.1.2 Toxoplasmosis
- •7.4.2 Helminthic Scleritis
- •7.4.2.1 Toxocariasis
- •7.5 Summary
- •References
- •8.1 Scleral Deposits
- •8.1.1 Scleral Protein Deposition
- •8.1.1.1 Porphyria
- •8.1.1.2 Cystinosis
- •8.1.1.3 Alkaptonuria
- •8.1.1.4 Amyloidosis
- •8.1.2 Scleral Lipid Deposition
- •8.1.2.1 Familial Hypercholesterolemia and Histiocytosis X
- •8.1.2.2 Age-Related Degeneration
- •8.1.3 Scleral Carbohydrate Deposition
- •8.1.3.1 Mucopolysaccharidosis
- •8.1.4 Scleral Mineral Deposition: Calcium
- •8.1.4.1 Hyperparathyroidism
- •8.1.4.2 Other Causes of Hypercalcemia
- •8.1.4.3 Age-Related Degeneration
- •Senile Scleral Hyaline Plaques
- •8.1.5 Scleral Pigment Deposition: Bilirubin
- •8.1.5.1 Jaundice
- •8.2 Scleral Thinning (Blue Sclerae)
- •8.2.1 Scleral Thinning in Inherited or Congenital Diseases
- •8.2.1.1 Marfan’s Syndrome
- •8.2.1.2 Osteogenesis Imperfecta
- •8.2.1.3 Pseudoxanthoma Elasticum
- •8.2.1.4 Ehlers–Danlos Syndrome
- •8.2.1.5 Keratoconus
- •8.2.1.6 Buphthalmos
- •8.2.1.7 Coloboma
- •8.2.1.8 Myopia
- •8.2.2 Scleral Thinning in Acquired Diseases
- •8.2.2.2 Paralimbal Scleromalacia
- •8.3 Scleral Thickening
- •8.3.1 Nanophthalmos
- •8.3.2 Scleropachynsis
- •8.3.3 Phthisis Bulbi
- •8.4 Scleral Tumors
- •8.4.1 Dermoid Choristomas
- •8.4.2 Epithelial Tumors
- •8.4.2.1 Papillomas or Intraepithelial Epitheliomas
- •8.4.2.2 Squamous Cell Carcinoma
- •8.4.3 Dense Connective Tissue Tumors
- •8.4.3.1 Nodular Fasciitis
- •8.4.3.2 Fibroma
- •8.4.3.3 Fibrous Histiocytoma
- •8.4.3.4 Sarcomas
- •8.4.4 Vascular Tumors
- •8.4.4.1 Hemangiomas
- •8.4.4.2 Lymphangiomas
- •8.4.5 Blood Cell Tumors
- •8.4.5.1 Leukemia
- •8.4.5.2 Lymphoma and Lymphosarcoma
- •8.4.6 Nervous Tumors
- •8.4.6.2 Neurilemmoma (Schwannoma)
- •8.4.7 Pigmented Tumors
- •8.4.7.1 Nevus
- •8.4.7.2 Melanocytoma
- •8.4.8 Secondary Tumors
- •8.5 Summary
- •References
- •9.1 Treatment of Episcleritis
- •9.2 Treatment of Scleritis
- •9.2.1 Medical Treatment
- •9.2.1.1 Rheumatoid Arthritis
- •9.2.1.2 Systemic Lupus Erythematosus
- •9.2.1.3 Polyarteritis Nodosa
- •9.2.1.4 Granulomatosis with Polyangiitis (Wegener)
- •9.2.1.5 Relapsing Polychondritis
- •9.2.1.7 Posterior Scleritis
- •9.2.1.8 Infectious Scleritis
- •9.2.2 Ancillary Therapy
- •9.2.3 Drug Management Responsibility
- •9.2.4 Surgical Treatment
- •9.3 Summary
- •References
- •Index
2.1 General Immune Response Considerations |
37 |
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to the cell surface. The combination of these degraded fragments in close juxtaposition to class II MHC glycoproteins forms the recognition unit for the helper TCRs speciÞc for the epitope of the antigen [24Ð26]. Antigen-presenting cells produce a variety of soluble factors during the presentation of the antigen to T-helper lymphocytes, including IL-1, which promotes the differentiation of both T and B lymphocytes.
LangerhansÕ cells are also important antigenpresenting cells [27], particularly for the eye. They are derived from bone marrow macrophage precursors and, like macrophages, they also possess a high density of class II MHC glycoproteins on their cell surfaces (HLA-DR), along with receptors for complement component (CR1/ CD35) and the Fc portion of immunoglobulin G (CD16). Unlike macrophages, LangerhansÕ cells have a racket-shaped cytoplasmic granule (the Birbeck granule), are not phagocytic, and have the characteristic surface molecule CD1.
Other cells that do not arise from the monocyte/ macrophage lineage may also be important in processing and presenting antigen; B lymphocytes, constitutively rich in class II MHC glycoproteins, are functionally important as antigen-presenting cells, particularly when the B lymphocyte is speciÞc for the antigen being presented.
Cells other than macrophages, LangerhansÕ cells, or B lymphocytes can acquire the ability to ÒpresentÓ antigens through the induction of class II MHC glycoproteins on their cell surface under the inßuence of cytokines (interferon g and tumor necrosis factor); these cells include connective tissue Þbroblasts, corneal endothelial cells, or vascular endothelial cells [28, 29]. It has been suggested that such induction of expression of ÒinappropriateÓ class II MHC glycoproteins might contribute to the pathogenesis of a variety of autoimmune diseases [30].
2.1.1.3 Polymorphonuclear Granulocytes
Polymorphonuclear granulocytes are leukocytes that form part of the natural immune system. They play a central role in host defense through phagocytosis, but if they accumulate in excessive numbers, persist, and are activated in an uncon-
trolled manner the result may be deleterious to host tissues. As the name suggests, they contain a multilobed nucleus and many granules. Polymorphonuclear leukocytes are classiÞed as neutrophils, basophils, or eosinophils, depending on the differential staining of their granules.
Neutrophils
Neutrophils represent over 90% of the circulating granulocytes. They possess surface receptors for the Fc portion of IgG (CD16) and for complement components, including C5a (important in chemotaxis), and CR1 (CD35) and CR3 (CD11b) (important in adhesion and phagocytosis). When appropriately stimulating by chemotactic agents (complement components, Þbrinolytic and kinin system components, and products from other leukocytes, platelets, and certain bacteria), neutrophils move from blood to tissues through margination (adhesion through endothelial cells) and diapedesis (movement through the capillary wall). Neutrophils release the contents of their primary (azurophilic) granules (lysosomes) and secondary (speciÞc) granules (Table 2.3) into an endocytic vacuole, resulting in phagocytosis of a microorganism or in tissue injury (type III hypersensitivity reactions or immune complexmediated diseases) [31, 32]. Secondary granules release collagenase, which participates in connective tissue degradation. Aside from the products secreted by the granules, neutrophils also release lipids, such as an arachidonic acid derivatives as well as reactive oxygen derivatives [32].
Eosinophils
Eosinophils represent 3Ð5% of the circulating granulocytes. They possess surface receptors for the Fc portion of IgE (low afÞnity) and IgG (CD16) and for complement components. Eosinophils play a specialized role in allergic and parasitic conditions. Although less important, they also participate in type III hypersensitivity reactions or immune complex-mediated diseases following attraction to the inßammatory area by products from mast cells, basophils (eosinophil chemotactic factor of anaphylaxis, ECF-A), and complement. Eosinophils release the contents of