Epiphora is the term commonly used to describe a watery eye. More specifically, lacrimation describes persistent welling of tears in the eye and epiphora is when these spill over. It is caused by:

• Overproduction of tears
• Inadequate/blocked drainage.
• Patients tend to experience this as a nuisance more than anything else. However, both lacrimation and epiphora can be associated with interference in vision ("It's like looking through pool water all the time.") and the surrounding skin can get very sore and excoriated from the constant wiping of tears associated with epiphora. There may also be underlying conditions that need to be addressed.

Cause

Overproduction of tears:

• Lid or lash malposition, eg trichiasis or entropion.
• Lid margin disease, eg blepharitis.
• Tear film deficiency (inappropriate reflex reaction).
• Corneal foreign body.
• Conjunctivitis.
• Corneal disease.
• Inflammatory disease, eg uveitis, scleritis.
• It may occasionally be a presentation in congenital glaucoma.
• Inadequate Drainage of Tears:
• Punctal malposition (lid laxity, eg ectropion).
• Stenosis or obstruction at any point along the nasolacrimal duct, eg congenital nasolacrimal duct obstruction - the most common cause of epiphora in childhood, lacrimal sac mass or mucocele, dacryocystitis.
• Lacrimal pump failure, eg facial palsy.
• Nasal obstruction, eg mass, inflammation or scarring.
• Previous surgery or trauma.

Presentation

Epiphora is simply a watering eye. There may be additional symptoms or signs depending on the underlying aetiology - follow links above. There are a few pointers that can help guide your diagnosis:

• Medial spillage suggests impaired drainage.
• Lateral spillage is more common with lower lid laxity.
• Reflex watering from a tear film deficiency is more likely to occur in dry, warm conditions or where blink rate is reduced, eg computer work.
  A simultaneous runny nose suggests overproduction.
• 'Crocodile tears' are associated with facial palsy and arise as a result of neurogenic reflex watering (thought of food, eating or chewing)

Investigation

In the eye clinic, steps are taken to identify which of the two groups of conditions the epiphora falls in, then refining the diagnosis through clinical examination ± investigation. Assessments include:

• Syringing: saline is irrigated through the canaliculi via the puncti after instilling a drop of local anaesthetic. Reflux through the upper canaliculus suggests obstruction at the common canaliculus. If the patient feels it trickling at the back of the throat, there is some degree of patency at least.

Management

This depends on the underlying cause.

Bloody tears suggest a sac tumour (rare), canaliculitis or trauma to the canaliculi. Lacrimal sac swelling may be due to dacryocystitis or a tumour.

Impaired drainage due to lid malposition or stenosis at various points along the nasolacrimal duct tends to involve surgery. This can be as minor as enlarging the punctum (drain hole on eye lid) to repairing the eye lid malposition.

• Dacryocystorhinostomy (DCR) is the procedure that creates an anastomosis between the lacrimal sac and the nose. The procedure may be external (open) or endoscopic, the former still being considered the gold standard. Although there are more associated complications (rare in themselves), the success rate is 90-95% compared with 80% success with endoscopic surgery and 70-80% success with endoscopic laser procedures.