Chronic tearing of the eye is usually due to blockage of the tear-conducting passages. The cause of the obstruction may be a scar due to injury, chronic inflammation of the mucous membranes leading to stenosis, a foreign body or pressure from a tumor. Most often chronic inflammation of the mucous membranes causes the obstruction, which is usually located at the bottom of the tear sac or in its extension downward into the nasal cavity, namely, the nasolacrimal duct.
Such interference with tear conduction predisposes to chronic infection in the blocked duct. To drain and cure this infection and to restore normal conduction of tears into the nose, a new opening is made above the obstruction through the bone that separates the tear sac from the nasal cavity. In making this opening from the nose to the tear sac, the greatest difficulty, as Bookwalter1 stated, is encountered in enlarging the