External Eye and Tear‑Duct Infections
Introduction
Infections of the lacrimal apparatus, eyelids and periorbital soft tissues are common in emergency and urgent‑care settings. Many are self‑limited but some threaten vision or may spread intracranially.
Priorities are to preserve vision, control infection, relieve pain and obstruction, practise antimicrobial stewardship, and arrange definitive care for recurrent or obstructive disease (e.g. referral for dacryocystorhinostomy where indicated) (NICE IPG113; GOV.UK Managing common infections).
Anatomical and clinical framework A simple anatomy‑first approach helps localise disease and guide management:
- Lacrimal apparatus: lacrimal gland (superolateral orbit) → canaliculi → lacrimal sac → nasolacrimal duct. Obstruction predisposes to tear stasis, epiphora and infection.
- Eyelid structures: lid margin (lashes, glands of Zeis/Moll), meibomian glands (tarsal plate). Infections may be anterior (lash follicle), tarsal (meibomian) or diffuse.
- Orbital septum: barrier at the orbital rim. Infection anterior to it = preseptal (periorbital) cellulitis; posterior = orbital cellulitis - the latter is sight‑ and life‑threatening.
Lacrimal‑apparatus infections
Dacryocystitis
- Pathogenesis: infection of the lacrimal sac secondary to nasolacrimal duct obstruction (congenital, inflammatory, neoplastic, traumatic or iatrogenic). Tear stasis promotes bacterial overgrowth.
- Presentation: acute cases cause tender medial canthal swelling, erythema, mucopurulent discharge and sometimes fever; chronic disease produces persistent epiphora and intermittent discharge.