Tearing (Wet Eye)
Tears on the surface of the eye drain through the tear duct, as follows. Tears flow into the puncta (small openings along the edge of the upper and lower eyelids near the nose), then through the canaliculi (narrow drainage channels in the eyelids) to the lacrimal sac (on the side of the nose), and then down the nasolacrimal duct into the nose. A blockage anywhere along that pathway may cause tearing and potentially infection. Infection in the lacrimal sac (dacryocystitis) causes redness, swelling, and tenderness on the side of the nose, often with pus training from the eye.
A blocked tear duct is relatively common at birth (congenital nasolacrimal duct obstruction), but usually resolves spontaneously over the first year of life. If it fails to resolve and it is symptomatic (tearing, crusting, infections), treatment options include probing of the tear duct and sometimes placement of a temporary silicone tube stent, both of which carry a very high success rate. A blocked tear duct may also develop later on in life (acquired nasolacrimal duct obstruction) for many possible reasons, e.g. facial trauma. While placement of a silicone tube stent is sometimes successful in adults with a partial tear duct blockage, a severe obstruction usually requires dacryocystorhinostomy (DCR), which involves creating a new drainage pathway from the lacrimal sac into the nose to bypass the blockage. This can be done either through a small skin incision (external DCR) or through the nose (transnasal endoscopic DCR). The skin incision usually heals quite nicely, leaving a minimal scar in most cases. When there is complete blockage of the upper and lower canaliculi (in the eyelids), placement of a Jones tube (a permanent glass tube which drains tears from the inner corner of the eye into the nose) may be necessary to alleviate the tearing.