Pathology of the Conjunctiva

Abstract

The conjunctiva is a mucous membrane that covers and connects the posterior surface of the eyelids to the anterior surface of the eyeball. The conjunctiva plays a critical role in maintaining ocular health through its protective, nutritive, and immunologic functions. The conjunctiva contributes to the stability of the tear film by secreting mucin. Conjunctival vasculature provides nutrition to the avascular cornea. The conjunctiva forms a mechanical barrier to infectious agents and toxins and plays an important role in immunologic surveillance and immune-medicated responses as mucosa-associated lymphoid tissue. The conjunctiva can be involved by various infectious, inflammatory, neoplastic, and degenerative disease processes. The most common pathologic processes of the conjunctiva are degenerative and inflammatory in nature, such as pinguecula, pterygium, and exuberant granulation tissue. The most common conjunctival malignancy is squamous cell carcinoma. This chapter reviews conjunctival anatomy and histology and various disease processes with an emphasis on pathology. Conjunctival pathology is considered in the following categories: (1) congenital and developmental anomalies, (2) inflammations and infections, (3) degenerations, (4) tumors, and (5) systemic diseases.