This is just a very brief tidbit but I thought it might possibly be of interest to some of you with epiphora:

Punctal stenosis: definition, diagnosis, and treatment.

Acquired punctal stenosis is a condition in which the external opening of the lacrimal canaliculus is narrowed or occluded. This condition is a rare cause of symptomatic epiphora, but its incidence may be higher in patients with chronic blepharitis, in those treated with various topical medications, including antihypertensive agents, and especially in patients treated with taxanes for cancer. The purpose of this review is to cover the medical literature, focusing in particular on definition, incidence, risk factors, etiology and treatment options.
Clin Ophthalmol. 2012;6:1011-8. Epub 2012 Jul 3.
Soiberman U, Kakizaki H, Selva D, Leibovitch I.
Source
Division of Oculoplastic and Orbital Surgery, Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel.