The conjunctiva is subdivided into three parts depending on location: palpebral conjunctiva, bulbar conjunctiva and conjunctival fornix. Histologically the conjunctiva is divided into three layers.From superficial to deep these are epithelial, adenoid and fibrous. These conjunctival layers contain a wide range of structures that includes glands, melanocytes, langerhans cells, mast cells and lymphoid tissue.
The arterial blood supply to conjunctiva is made up of branches of ophthalmic artery, the anterior and posterior conjunctival arteries. These are branches of anterior ciliary arteries and palpebral arcades respectively. The venous drainage follows the arteries. Posterior conjunctival veins drain the veins of the lid and anterior conjunctival veins drain anterior ciliary vein to ophthalmic vein.
The lymphatic drainage of the conjunctiva depends on the region of the conjunctiva. Lymphatics in palpebral region drain into the lymphatics of eyelids. In bulbar conjunctiva, lymphatics from lateral side drain into the superficial preauricular lymph nodes & lymphatics from medial side drain to deep sub maxillary nodes.
The first division of the trigeminal provides nerve supply to the conjunctiva.