Because the conjunctiva is an exposed surface, it can be affected by a variety of organisms, allergens, and toxic agents, which can initiate an inflammatory response referred to as conjunctivitis. Depending on the onset and duration, etiology, constituents of the inflammatory infiltrate, or macroscopic and microscopic appearance of the conjunctiva, this response may be categorized as
acute or chronic
infectious or noninfectious
papillary, follicular, or granulomatous
Figure 5-2 Ocular surface choristomas. A, Clinical photograph of a solid limbal dermoid. B, Higher magnification shows hairs emanating from the dermoid. C, Histology of the dermoid shows keratinized epithelium, dense bundles of collagen in the stroma, and hair follicles with associated sebaceous glands (arrows).D, A dermolipoma differs from a dermoid in that it also contains a significant amount of mature adipose tissue (A). This dermolipoma also contains dermal adnexal structures, including a hair follicle (H) and sebaceous glands (S). E, Complex choristomas combine features of multiple types of choristomas, in this case osseous, with the presence of bone (B), and dermolipoma, with the presence of adipose tissue (A).
(Parts A and B courtesy of Morton E. Smith, MD; parts C–E courtesy of George J. Harocopos, MD.)
See BCSC Section 6, Pediatric Ophthalmology and Strabismus, and Section 8, External Disease and Cornea, for additional discussion of conjunctivitis.
Acute or Chronic Conjunctivitis
Most cases of conjunctivitis are not biopsied; they are diagnosed on the basis of the acute nature of the clinical presentation or the chronicity of the case, as well as the ophthalmologist’s clinical acumen. See BCSC Section 8, External Disease and Cornea, for additional discussion on the clinical distinction between acute and chronic conjunctivitis.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.