Congenital atresia of these puncta has been recorded in foals, by
Hollmann and obstruction as the result of inflammation, by Lafosse,
Verjaus and Tyvaert, and of the entrance of the seeds of bromus by
Stockfleth.
Apart from congenital atresia and impaction of foreign bodies the
_symptoms_ are those of conjunctivitis, with escape of tears over the
face (epiphora). Injection of aseptic water into the lower puncta and
its escape by the upper, and by the nasal orifice, will determine the
patency or otherwise of the various channels.
_Treatment_ consists in astringent collyria to check the inflammation,
in the removal of any foreign body, in the dilation or slitting of the
lachrymal canaliculi, and in case of complete atresia, in incising the
lachrymal sac. Slitting of the canaliculi is accomplished by a small
probe pointed bistuory (canaliculus knife). The lid is drawn away from
the carnucle, and the probe point inserted at first downward, then
inward and backward, and when it is well inside the sac the handle is
brought to the vertical and the walls of the duct slit open.
In case of atresia Leblanc recommends to seize the inner canthus with
rat tooth forceps so as to include the structures about the sac and to
plunge the bistuory directly into the sac. Then by the aid of a
whalebone staff he passes three silk threads through the duct and fixes
them in place by attaching them to a copper ring at each end. This is
retained in place and moved daily until the passage has been definitely
healed and its permanency assured.