periocular

Periocular refers to the region surrounding the eye, typically including the eyelids, lacrimal apparatus, conjunctiva, and the skin and soft tissues around the eye. The term is used in anatomy, ophthalmology, dermatology, and cosmetic medicine to describe structures and conditions that affect the eye-adjacent region. In clinical usage, periocular is often contrasted with orbital (within the eye socket beyond the orbital septum); some sources distinguish periocular (preseptal) from periorbital in casual language, but terminology varies.

Anatomy: The major components of the periocular region include the eyelids (upper and lower), their margins and tarsal plates, the eyelashes, medial and lateral canthi, the palpebral conjunctiva, and the lacrimal apparatus (puncta, canaliculi, lacrimal sac and nasolacrimal duct). The overlying skin, subcutaneous tissue, and eyelid muscles contribute to movement and protection of the eye. Superficial orbital fat and the orbital septum lie at the boundary with deeper structures; posterior periocular tissues and intraorbital contents are not usually described as periocular.

Clinical relevance: Periocular disease encompasses blepharitis, chalazion and styes, eyelid dermatitis, and periocular cellulitis. Procedures such as periocular injections or dermal fillers are performed to treat cosmetic or inflammatory conditions around the eye. In imaging and diagnosis, the periocular region is evaluated to distinguish anterior, preseptal pathology from deeper orbital disease.