Excessive tearing may occur as a reaction to dry or irritated eyes or as a result of problems with the eyelids and/or tear drainage system. A number of structures have to be in perfect working order for tears to drain normally: the eyelids must be in the proper position to channel the tears to the opening of the tear duct drain, the opening to the drain must be large enough to accommodate the flow of tears and the drainage ducts themselves must be open.
An Easy Way to Understand Excessive Tearing
A simple analogy that will help the patient understand tearing better is the drainage of water down a kitchen sink drain. If the water sits on the countertop and does not flow into the drain, it will simply pool and eventually drain over the edge. If the opening to the drain is too small, the water will eventually overflow. If the drainpipe under the sink is blocked, the water will not drain successfully. Similarly, problems with tear drainage may occur with laxity or malposition of the eyelids, narrowing of the opening to the tear duct drainage system and blockage of the tear duct themselves.
Increased Tear Production and Dry Eyes
Inflammatory conditions like rheumatoid arthritis and Sjögren’s disease, as well as aging and menopause, can lead to decreased tear production. As tear production diminishes, the surface of the eye starts to dry out. The brain senses the eye is both dry and irritated and in turn signals the main tear gland to flush the eye. As a result, the dry eye paradoxically tears and becomes watery. Patients with dry eyes note intermittent tearing during activities like reading, driving, watching TV or using a computer. These all cause the eye to dry out because the eye blinks less during these activities.
Why do we Develop Obstructed (Blocked) Tear Drainage Ducts?
Blockage of the tear drainage ducts (known as the nasolacrimal duct, see image below) may occur at birth (present in 6% of all newborns). It can also be due to a multitude of other reasons including aging, trauma, inflammatory conditions, medications and tumors. If the tear passageways become blocked, tears cannot drain properly and may overflow from the eyelids onto the face as if you were crying. In addition to excessive tearing you may also experience blurred vision, mucous discharge, eye irritation and painful swelling in the inner corner of the eyelids.
The treatment for tearing is of course related to the underlying cause of the condition. The eyelids must be placed in proper position to channel the tears into the drainage ducts. The opening to the ducts must be made large enough to accommodate the flow of tears, and the drainage ducts themselves must be opened if they are blocked.
For Tearing Caused by Dry Eyes
The treatment for tearing caused by dry eyes includes:
- Replacing tears with lubricants (artificial tears), which can be purchased over the counter
- Medications like Restasis that decrease inflammation in tear glands and encourage natural tear production to resume
- Plugging of the tear drain
Other medical conditions such as allergies, infections and misdirected eyelashes can also cause increased tear production. These conditions can be identified during your examination.
For Blocked Tear Ducts
Treatment of blocked tear ducts typically requires surgical reconstruction to either open the natural drain or to bypass a drain that has been ruined by scar tissue or trauma. Tearing in infants is generally treated if the symptoms of discharge and crusting do not resolve by age one. In most children, the tear passages are present and normal but are blocked by a membrane that can be opened through a straightforward outpatient procedure.
- Tearing may occur due to irritation of the eyes or failure of the tears to flow through the natural drainage system.
- 6% of all infants are born with blocked tear ducts
- The majority of children born with blocked ducts won’t require surgery, as the ducts can open naturally.
- If the ducts do not open by age one, an outpatient procedure should be performed to allow the tears to drain properly.
- Tearing in adults may be related to dry eyes, eyelid malposition, blockage of the drainage ducts or a combination of these conditions.
- Blocked tear ducts in adults may occur for a number of reasons and usually require bypass (DCR) surgery for repair.
- DCR surgery is an outpatient procedure that is performed either internally through the nose or through a small incision placed in a natural fold in the lower eyelid so as to minimize visible scarring.