Surgery of the conjunctiva

Abstract

Background: Dry eye is characterized by aqueous tear deficiency or excessive tear evaporation at the ocular surface, both leading to tear film instability that results in ocular surface epithelial damage. In addition to the lacrimal gland, the meibomian gland, cornea, and conjunctiva also contribute to the formation of the tear film via the production of goblet-cellderived mucin and the expression of membrane-associated mucin. The conjunctiva can be linked with dry eye through various mechanisms such as inflammation, disturbance of the tear film, and conjunctival fibrosis. Thus, normalization of the conjunctiva is important for the management of dry eye.

Materials and methods: Conjunctival diseases associated with dry eye include conjunctivochalasis, superior limbic keratoconjunctivitis, pterygium and pinguecula, and severe ocular surface diseases such as Stevens-Johnson syndrome and ocular cicatricial pemphigoid. The associated pathophysiology and surgical procedures for these disorders are analyzed and described. The major concept of conjunctival surgery for dry eye is to smoothen the surface in order (1) to reduce blink-associated microtrauma, (2) to reconstruct the tear meniscus and conjunctival fornix and their respective functions as reservoirs for tears, and (3) to reduce conjunctival inflammation by the removal of abnormal fibrous tissue combined with the use of mitomycin C and/or amniotic membrane.

Results: Conjunctivochalasis and pterygium result in signs and symptoms of dry eye by inducing dysfunction of the tear meniscus and/or an ectopic tear meniscus. Therefore, the resection of redundant conjunctiva and abnormal tissue in pterygium is an effective procedure for normalizing the tear film. If cicatrizing conjunctivitis results in tear-film instability due to conjunctival inflammation and squamous metaplasia, reconstruction of ocular surface epithelium is vital for its resolution.

Conclusion: In order to effectively manage dry eye due to conjunctival disease, it is important to understand not only the surgical procedure but also the pathomechanisms of conjunctival changes leading to signs and symptoms of tear-film deficiencies.