The lacrimal glands are on the superior temporal side of the orbits. The tear film excreted over the eye drains via the lacrimal puncta (found at the medial side of the upper and lower eyelid) through the lacrimal sac, lacrimal duct and inferior meatus (just lateral to the inferior turbinate) into the nasal passages. Dry eyes may be due to insufficient tear secretion, and watering eyes may be due to blockage of the drainage system.
Acute dacryocystitis
This is acute inflammation of the tear sac which is located medial to the medial canthus. This may spread to surrounding tissues and result in systemic upset. Immediate antibiotic therapy may resolve the infection. Failure leads to local abscess formation.
Nasolacrimal duct non-canalization
The nasolacrimal duct may not be canalized at birth and may not open fully until 3 months old. Tear sacs tend to get infected and a sticky discharge is produced. Ask an ophthalmologist to teach the mother to massage the sac to empty the contents four times daily and then apply antibiotic (eg gentamicin) eye drops. Should this fail after several months, probing of the duct under anaesthesia is an option.
Chronic dacryocystitis
This typically occurs in the middle-aged and elderly. There is lacrimal sac distension, discharge of mucopus into the eye nasolacrimal duct block. Syringing the lacrimal drainage system is done early to clear the system (may need repeating). If the nasolacrimal duct is permanently blocked, dacryocystorhinostomy establishes communication between the lacrimal sac and the nasal cavity. ΔΔ: Squamous cell cancer of the lacrimal drainage system: do CT or MRI of all masses arising in the medial canthus.15
Dacroadenitis
Lacrimal gland inflammation causes pain and swelling on the temporal side of the upper eyelid, which may become S-shaped.
Cause
Viral (mumps, measles, influenza) or gonococcal. Chronic swelling can occur in sarcoid, TB, lymphatic leukaemia, or lymphosarcoma.
Tear production
The volume of tears normally in the eye is 6L, the turnover rate being 1.2L/min. Tears are similar in electrolyte concentration to plasma, but rich in proteins, especially IgA. They also contain lysozyme and β-lysin which have antibacterial properties.
Dry eye syndrome (keratoconjunctivitis sicca)
This may be due to tear production by the lacrimal glands in old age, or, less commonly, in: Sj gren's syndrome associated with connective tissue disorders (especially RA); mumps; sarcoidosis; amyloid; lymphoma; leukaemia; haemochromatosis. Other causes: excess evaporation of tears (post-exposure keratitis); or mucin deficiency in the tears (avitaminosis A, Stevens-Johnson syndrome, pemphigoid, chemical burns). Schirmer's test (strip of filter paper put over-lapping lower lid; tears should soak >15mm in 5min) reveals insufficient production. Artificial tears may be used for symptomatic relief.
Excess lacrimation
Causes
Emotion (joy or sorrow),1 corneal abrasions or foreign body, conjunctivitis, iritis, acute glaucoma.
Epiphora
ie normal volume, but not normally drained to the inferior meatus of the nose.
Causes
Ectropion, entropion, drainage system blockage (idiopathic, or rarely from head and neck tumours).
Treatment
Dacryocystorhinostomy (eg endoscopic) for nasolacrimal duct obstruction; surgery for other causes.
 |
| Anatomy of the lacrimal drains |
Advertisements
