A blockage in tear outflow leads to a watery eye.
Our tears are blinked into the inner corner of our eyes where they enter tiny openings called punctae on the edge of our lids. From here, the tears drain into tiny channels called canaliculi which connect into our tear sac and then down the tear duct into our nose. A blockage, whether by scar tissue, infection, trauma, or tumor growth, can cause the tears to back up and create a watery eye.
The most common site for blockage is in the tear duct near the end of the drainage passageway into the nose. If it is only a partial blockage, it may be possible to improve the watery eye by stretching this narrowed area open and leaving a very thin soft silicone stent in place temporarily. If it is a complete blockage, the watery eye may also become sticky and goopy, and more prone to infection. In these cases, a surgery is performed to reconnect the tear sac to the nose, bypassing the blockage in the duct. This is called a dacryocystorhinostomy procedure, or DCR. It is typically done under deep sedation or general anesthesia on an outpatient basis, has a high success rate, and recovery is fairly short, with most patients able to return to work after a few days.