Augenwinkel

Augenwinkel, in medical terminology also called canthus, refers to the angle where the upper and lower eyelids meet. There are two Augenwinkel: the medial (nasal) canthus near the nose and the lateral (temporal) canthus toward the temple. The medial canthus marks the inner corner of the eye, while the lateral canthus forms the outer corner.

Anatomically, the medial canthus hosts structures related to tear drainage, including the lacrimal caruncle and the plica semilunaris. The lacrimal puncta, small openings on the medial margin, lead into the canaliculi, then to the lacrimal sac and nasolacrimal duct, forming the tear drainage pathway. The lateral canthus is stabilized by the lateral canthal tendon, contributing to the shape and position of the outer eyelid corner. Together, the Augenwinkel help create a seal for the tear film and protect the eye from environmental inputs, while guiding tear drainage toward the medial tear drainage system.

Clinical relevance includes variations in canthal position and structure, such as telecanthus (increased distance between medial canthi) or canthal tilt, which can influence eyelid aesthetics and function. Disorders affecting the medial canthus, like nasolacrimal duct obstruction leading to epiphora, or ptosis and eyelid laxity affecting the canthal region, may require ophthalmologic assessment. Reconstructive and oculoplastic procedures often consider the canthi to restore eyelid closure, contour, and tear drainage.