The anatomy of the conjunctiva should be considered when reconstructing and replacing the conjunctiva. Please see StatPearls' companion reference, "Anatomy, Head and Neck, Eye Conjunctiva," for further information. The human conjunctiva is an epithelial layer composed of nonkeratinized stratified squamous epithelium and stratified columnar epithelium. The conjunctiva has goblet cells (see Image. Anatomy and Physiology of Mucous Membrane Graft). The conjunctiva is a complex structure that contains lymphatic channels, blood vessels, fibrous tissue, melanocytes, T- and B-cell lymphocytes, accessory lacrimal glands, and Langerhans cells. Glands of Krause are found within the deep fibrous layer of the conjunctiva, and the goblet cells, which are greatest in the fornices, secrete mucin. The conjunctiva contributes to the protection of the eye with the production of mucus and tears. The conjunctiva also provides mechanical protection for the eye and facilitates the free movement of the globe and eyelids. The conjunctiva lines the tarsus (or palpebral conjunctiva), where it lines the eyelid margin of the tarsus and the Tenon capsule. The flexibility of the fornical conjunctiva is important in the free movement of the globe and the eyelids. Loss or scarring of the conjunctiva from injury or disease can result in eyelid malposition, restriction of ocular movement with double vision, and dryness. When replacing the injured conjunctiva, materials such as amniotic membrane, hard palate grafts, nasal septal mucosa, autogenous conjunctiva, and tarsus with conjunctiva have been used. Ideally, clinicians should use a like-for-like replacement approach. Unfortunately, except for small defects, autogenous conjunctiva is limited by availability. Oral mucosal grafts are used in 2 forms: Oral mucous membrane grafting. Minor salivary gland grafting for the treatment of severe dryness. The oral mucosa shares biological properties with the conjunctiva, provides an easily accessible, universally available donor site, is technically easy to harvest, is low-cost, allows repeat harvesting, and is associated with few complications. Oral mucosa also serves as an autograft, avoiding the risks of allogeneic grafts. In 1912, Denig first described the use of the mucous membrane graft in lime burns. Subsequently, Weeks used mucous membrane grafts to correct trichiasis and symblepharon. Notably, the membrane does not contain goblet cells, which are present in the conjunctiva. Consequently, the membrane does not help treat dry eye disease unless it is transplanted with minor salivary glands. Moreover, in patients with concurrent limbal stem cell deficiency of more than 3 to 4 clock hours, a limbal stem cell transplant should be performed concurrently. The oral mucosa is rich in elastin, making it resistant to shearing and compression and highly vascular, facilitating graft uptake. The oral mucosa is histocompatible and exhibits minimal contraction at the transplant site. Indications for the use of mucous membrane grafts in ophthalmology include the following: After the removal of pterygia. Repair of contracted anophthalmic sockets. Globe surface and fornix reconstruction after tumor resection. Deformities of the eyelids (cicatricial entropion, keratinization of the eyelid margin after chemical burns, or Stevens-Johnson syndrome). Repair of erosions over glaucoma drainage devices. Repair over the scleral buckle exposure. Support of keratoprosthesis associated with corneal melt. Formation of the lining during conjunctivodacryocystorhinostomy or dacryocystorhinostomy . In addition to its structural role, mucous membrane grafting has gained prominence as a functional reconstructive modality for complex ocular surface disorders in which the restoration of a stable epithelial environment is essential (see Image. Clinical Indications for Ocular Mucous Membrane Grafting). The success of these grafts is closely linked to the vascularity of the recipient bed, control of underlying inflammation, and meticulous surgical technique. Preoperative optimization, including treatment of active cicatrizing disease, lubrication, and control of adnexal abnormalities, plays a crucial role in improving graft survival and long-term outcomes. Recent advances have also emphasized the role of mucous membrane grafts as an adjunct rather than a standalone procedure in many cases. In severe cicatricial conditions, particularly those associated with immune-mediated pathology, integrating systemic immunosuppression with staged reconstruction strategies has been shown to improve anatomical and functional outcomes. Furthermore, the concept of surface rehabilitation now extends beyond mere defect coverage to include restoration of fornix depth, preservation of ocular motility, and prevention of recurrent symblepharon. From a histological perspective, although mucosal grafts lack goblet cells, they demonstrate rapid epithelialization and adaptation to the ocular surface microenvironment. Over time, partial phenotypic modification has been observed, thereby improving surface lubrication. The inherent elasticity and resistance to keratinization make the oral mucosa particularly suitable for dynamic areas such as the fornices and eyelid margin. The role of mucous membrane grafting has also expanded in the era of keratoprosthesis and ocular surface prosthetic devices, where it provides durable tectonic support and reduces the risk of extrusion. In socket reconstruction, especially in contracted sockets, mucous membrane grafting helps restore volume and fornical architecture, thereby improving prosthesis retention and cosmesis. Despite its advantages, careful patient selection remains essential. Factors such as severe dry eye without salivary gland support, uncontrolled inflammation, and poor lid-globe apposition may compromise outcomes. Therefore, a tailored, interdisciplinary approach involving cornea specialists, oculoplastic surgeons, and ocular surface experts is critical to achieving optimal results.