Medial Canthus, Gross Anatomy

Description

Centered on the medial canthus of an adult female, the illustration focuses on the junction of the upper and lower eyelids at the medial palpebral commissure, where the lid margins converge and the eyelashes thin toward the caruncular region. Just medial to the bulbar conjunctiva, the lacrimal caruncle sits within the lacrimal lake, with the plica semilunaris positioned lateral to it as a conjunctival fold. The superior and inferior lacrimal puncta occupy the posterior aspect of each lid margin near the medial end, leading into the canaliculi that course medially toward the lacrimal sac deep to the medial canthal tendon (medial palpebral ligament). Orbicularis oculi fibers surround the canthus, with pretarsal fibers closest to the lid margin and preseptal fibers more anterior. Surgical and diagnostic work at the inner canthus depends on getting these relationships right, because the puncta sit posteriorly against the globe, not on the anterior lid skin, and minor rotation during lid tightening can displace them away from the tear meniscus and cause epiphora. Small distances matter. The medial canthal tendon anchors the tarsal plates to the anterior and posterior lacrimal crests, a key landmark during repair of medial eyelid lacerations where canalicular injury must be excluded and, if present, stented to prevent chronic tearing. Inflammation of the lacrimal sac (dacryocystitis) and nasolacrimal duct obstruction also localize to this region and are often discussed alongside the surface anatomy of the caruncle and puncta. Use this artwork in ophthalmic anatomy teaching, oculoplastics and lacrimal surgery references, and patient-facing education on tearing disorders, punctal stenosis, or canalicular laceration repair. It also fits well in emergency medicine and ENT publications covering medial canthal trauma and nasolacrimal drainage pathways. Anatomical accuracy verified by SciePro's Medical Advisory Board.