Tearing

Tearing is common. Tearing is due to two main causes: over production or under drainage. Tears are produced by the lacrimal and eyelid glands and are drained by the tear ducts. Over production is usually reflex tearing to an irritant. The most common culprit of irritation is dry eye. When the eyes are significantly dried, the clear surface of the eye, called the cornea, messages the lacrimal gland, which in turn increases tear production. This positive feedback, unfortunately, does not come with a negative feedback to turn off this mechanism. Therefore, more tears are produced than needed. Similarly, when there is allergen or foreign body on the eye, the lacrimal gland responds to this irritant and over produces tears. Under drainage is when the duct responsible for draining the tears becomes narrowed or completely closed. Common risk factors for the tear duct blockage are older age, female gender, history of significant seasonal allergy, sinus disease or chronic inflammation, or trauma to the nose. Of these risk factors, only seasonal allergy, sinus disease or chronic inflammation can be treated medically rather than surgically to help open up the tear duct. However, in long-standing conditions, the blockage may have already scarred down, in which case medication does not have an effect. 

Blockage occurs in one of three areas of the drainage system:

• Blockage of the tear drain in the nose (nasolacrimal duct obstruction)
• Blockage of the tear drain in the eyelid (canalicular obstruction)
• Blockage of the tear drain opening on the eyelid margin (punctal stenosis)

In infants, tear duct obstruction is usually caused by a thin membrane blocking the opening of the tear duct in the nose. This typically resolves itself before the child is one year old. During this time, the infant is treated conservatively with massages of the lacrimal system. If the problem persists or causes infection, it may be necessary to open the blocked tear duct surgically.

In adults, most under drainage tearing requires surgical intervention. Tear duct surgery options include:

Tear duct intubation (stenting) – For narrowed punctum, canaliculus or tear duct (usually related to medication), a soft, plastic tube can be placed in the tear duct for few months to prevent further or permanent closure. This procedure is done in the operating room under either intravenous sedation or general anesthesia, depending on the patient’s comfort level. Tube removal is simply performed in the office several months later and is painless. Tube has a high success rate if the blockage is partial and acute rather than chronic. It is also very tolerable, as rarely do patients feel the tube after the initial week.

Dacryocystorhinostomy (DCR) – If blockage to the tear duct is severe or chronic, an alternative communication needs to be created between the tear sac in the socket and the mucosa in the nose to allow tears to bypass the blockage and drain. This procedure is performed in the operating room under general anesthesia. It also involves placing a stent in the lacrimal duct for several months to help keep the new drainage system open. The stent is simply removed in the office and is painless. The stent is also very tolerable, as patients usually cannot feel the stent. The success rate of this surgery is 90-95%, especially when there is no history of tear sac infection or chronic inflammation.

Jones Tube placement (cDCR) – When there are no functioning lacrimal canaliculi in the eyelids, a rigid tube (the Jones tube) is placed in the inner corner of the eye into the nose. This Jones tube will stay in place permanently, although occasionally it needs to be replaced or repositioned. This procedure is usually the last resort, as the success rate is 50%.