Chapters authored
Histopathology of the Ocular Surface By Hind Alkatan and Tariq Alzahem
Three integral parts that cover the ocular surface are the conjunctiva, limbus, and cornea. The conjunctiva is a see-through mucous membrane that lines the internal surface of the eyelids and the front surface of the eyeball, ending at the limbus. It is highly vascular with a dense lymphatic network. The limbus forms the boundary between the transparent cornea and the opaque sclera. The cornea is a complex structure that provides a protective function and is responsible for about 75% of the optical power of the eye. Histology of these highly specialized biological materials as well as the ways in which individual components are structurally and functionally related will be discussed in this chapter. Then, we will go over the pathological oncology processes that can affect the ocular surface.
Part of the book: Histopathology
Optic Nerve: Developmental Anomalies and Common Tumors By Hind Alkatan, Daniah Alshowaeir and Tariq Alzahem
The optic nerve, also known as the second cranial nerve, is composed of axons that transmit visual information from the neurosensory retina to the visual cortex. There are multiple pathologies that can affect the human optic nerve. Congenital anomalies of the optic nerve include myelinated nerve fibers, morning glory syndrome, optic nerve choristoma, optic nerve coloboma, optic nerve hypoplasia and aplasia, and others. Tumors that can affect the optic nerve (ON) may occur primarily from within the nerve itself, from the surrounding optic nerve sheath (ONS), or secondarily spreading to the nerve from a distant site. They include optic pathway glioma, medulloepithelioma, oligodendroglioma, optic nerve sheath meningioma, and others. Here in this chapter, we will review the optic nerve anatomy, embryology, and physiology in addition to assessment of optic nerve function. Moreover, the clinical features, imaging findings, pathology, and treatment options of the most common and some rare congenital anomalies and primary tumors of the ON and sheath will be reviewed.
Part of the book: Optic Nerve
Corneal Dystrophies and Degenerations By Hind Alkatan, Norah Alkheraiji and Tariq Alzahem
The cornea is a complex structure with complex functions aiming to protect the internal ocular tissues and transmit and refract the coming light rays. Corneal dystrophies are a group of relatively infrequent genetic corneal disorders in which an abnormal material accumulates in the cornea causing variable loss of its clarity. On the other hand, corneal degenerations are more common and usually result from physiologic changes related to aging, particular disease, or long-standing environmental insults to the cornea. Ectatic corneal disorders are usually characterized by bilateral loss of corneal biomechanical strength leading to progressive thinning and bulging of the cornea with resultant astigmatism and decreased visual acuity. In this chapter, we will describe the basic embryological, anatomical, histologic, and physiological features of the cornea. Then, we will go over the clinical, histopathologic, medical, and surgical aspects of dystrophic, degenerative, and ectatic corneal disorders.
Part of the book: Frontiers in Ophthalmology and Ocular Imaging
Ocular Findings in Neurofibromatosis By Hind M. Alkatan, Sawsan S. Bakry and Mohammad A. Alabduljabbar
Neurofibromatosis (NF) is an inherited disease affecting multiple systems in the body. The eye is frequently affected in neurofibromatosis, and therefore ocular manifestations play a major role in the diagnosis of NF. This chapter aims to explore the spectrum of ocular manifestations found in neurofibromatosis highlighting the importance of ophthalmic exam in these patients. It will describe various intraocular manifestations involving the iris, lens, and retina. It will be focusing on glaucoma and the pathogenesis behind it in this group of patients. Moreover, periorbital and orbital involvement such as skin neurofibromas and optic nerve gliomas will be discussed along with some of their histopathological findings.
Part of the book: Neurofibromatosis
Periocular Hemangioma: Clinicopathological Aspects By Hind M. Alkatan, Dalal R. Fatani, Hala A. Helmi, Rakan Alsaad, Rahaf Altwijri and Munirah Aldofyan
Hemangiomas are pathologically considered to be developmental hamartomatous lesions. In the periocular region, capillary hemangioma is commonly encountered in infants and children, and it is of particular importance because of its critical location if involving the eyelid with obstruction of the visual axis. In this chapter, we aim to briefly discuss the pathogenesis and etiology of such lesions, describe the histopathological features, and the diagnostic immunohistochemical stains used, with differentiating features between infantile hemangioma and capillary hemangioma in adults. In the periocular region, the clinical appearance and manifestations depend on three primary locations of the hemangioma: the superficial, subcutaneous, and deep orbital hemangiomas. Treatment options are similar to hemangioma elsewhere, however, as mentioned above, early treatment may be advocated to avoid developing amblyopia (lazy eye) because of visual deprivation or obstruction. The most used therapy in the periocular region is beta-blockers, either orally or locally. Intralesional steroids and sclerosing agents may also be used. Surgical intervention is reserved for deep orbital-selected lesions.
Part of the book: Common Childhood Diseases - Diagnosis, Prevention and Management [Working title]
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