- •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
8.1 Scleral Deposits |
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8.1.2Scleral Lipid Deposition
8.1.2.1 Familial Hypercholesterolemia and Histiocytosis X
Disorders of lipid and lipoprotein metabolism may lead to deposition of lipid-containing histiocytic foam cells in tissues: xanthomas. Xanthomas can be seen in conjunctiva or episclera of normal individuals without abnormalities in their serum lipids. Xanthomas can be seen in sclera of individuals with xanthoma disseminatum without abnormalities in their serum lipids; they appear as dark mahogany-brown papules over sclera as well as over flexural creases, mucous membranes, and cornea [40].
Scleral xanthomas also may appear associated with diseases, such as type II hyperlipoproteinemia (hyperbetalipoproteinemia) or familial hypercholesterolemia, and with histiocytosis X (Hand-Shüller-Christian disease, Letterer-Siwe disease). Any patient with scleral xanthomas should be examined for serum lipid abnormalities.
8.1.2.2 Age-Related Degeneration
With advancing age, the sclera becomes slightly yellow from the deposition of lipids, including cholesterol esters, cholesterol, free fatty acids, triglycerides, and sphingomyelin [41, 42]. Collagen acts as a trap for these lipid fractions. The lipid fractions which show the greatest increase in concentration with age are cholesterol esters and sphingomyelin [41]. The lipid deposition may be particularly obvious in old scars.
Lipid deposition in sclera also may occur following severe scleral inflammation at any age.
type VI is a recessively inherited syndrome which is characterized by the accumulation of glycosaminoglycan dermatan sulfate (mucopolysaccharide) in several tissues of the body; this accumulation is due to deficiency of the enzyme N-acetyl-galactosamine-4-sulfate sulfatase (arylsulfatase B). Other systemic and ocular manifestations in mucopolysaccharidosis type VI are gargoyle-like facial dysmorphism, skeletal dysplasia, aortic stenosis, umbilical hernia, corneal clouding, and optic atropy. Patients with the severe form die in their teens from hydrocephalus due to meningeal involvement.
Mucopolysaccharide deposition between the collagen fibers of the posterior sclera adjacent to the macula was detected in a 50-year-old man with bilateral mottling of the retinal pigment epithelium in the macular region; [44] mucopolysaccharide accumulation was thought to be the cause of choroidal compression and maculopathy.
Histopathologic detection of corneal and scleral deposits of an unusual glycosaminoglycan (mucopolysaccharide) was found in a 68-year- old patient with clinical corneal stromal opacities since infancy; [45] there were no deposits in other ocular or extraocular tissues. The authors suggested the possibility of a diffusion-like process from cornea to sclera. Accumulation of mucopolysaccharide has been reported throughout the anterior segment [46], implicated as causing glaucoma and uveal effusions [47, 48].
8.1.4Scleral Mineral Deposition: Calcium
8.1.4.1 Hyperparathyroidism
8.1.3Scleral Carbohydrate Deposition Calcium deposition in cornea, conjunctiva, and
8.1.3.1 Mucopolysaccharidosis
Histopathologic scleral involvement may occasionally occur as a result of mucopolysaccharide deposition.
Mucopolysaccharide deposition between the collagen fibers of the posterior sclera may occur in mucopolysaccharidosis type VI or Maroteaux– Lamy syndrome [43]. Mucopolysaccharidosis
sclera may occur as a result of the calcium and phosphorous imbalance seen either in primary causes of hyperparathyroidism, such as benign adenoma or hyperplasia of the parathyroid glands [49–54], or in secondary causes of hyperparathyroidism, such as chronic renal disease [52, 54, 55]. The calcium is deposited in the form of hydroxyapatite crystals in the nucleus and cytoplasm of the stromal cells of the sclera [53].