=Immediate.= 1. _Inability to find the sac._ This may happen to a beginner, and is generally due to the fact that the dissection is carried too much inwards towards the nose. It should not occur if the guides to the sac carefully borne in mind, namely, the internal tarsal ligament and, on the inner side, the lachrymal crest, which can easily be felt with the finger or forceps in the wound. [Illustration: FIG. 168. EXCISION OF THE LACHRYMAL SAC. Showing the internal tarsal ligament in the upper part of the wound with the sac lying beneath.] [Illustration: FIG. 169. EXCISION OF THE LACHRYMAL SAC. Showing the method of defining the upper end of the sac. The internal tarsal ligament has been divided and the sac is well pulled forward with forceps.] 2. _Opening the conjunctival sac._ This may take place when dividing the canaliculi. It is more likely to occur if the deep fascia has been imperfectly divided before carrying out the dissection to the inner side. As a rule the opening heals readily. 3. _Opening of the orbit_, due to the division of the fascia attached to the posterior lip of the lachrymal groove. It is recognized by the fact that orbital fat presents in the wound, and for this reason it makes the operation more difficult. It is most likely to happen when the lower end of the sac is being divided. It lays the orbit open to the possibility of septic infection. The internal rectus has been divided, no doubt due to the fact that the fascia, which passes from the outer surface of this muscle, is attached to the posterior lip of the lachrymal groove, and the muscle has been thereby pulled up into the wound; with ordinary caution such an accident is impossible. 4. _Injuries to the cornea._ Corneal abrasions by the clumsy insertion of retractors may lead to severe corneal ulceration. =Remote.= 1. _Epiphora._ Normally the lachrymal secretion is largely removed from the conjunctival sac by a process of evaporation. It is only when the hypersecretion of tears takes place that the lachrymal apparatus is called much into use. As a rule, patients who have had the lachrymal sac excised do not complain of epiphora, except in a cold wind. Occasionally this epiphora may be so troublesome that removal of the palpebral portion of the lachrymal gland is desirable for its relief. There is no fear of the conjunctival sac becoming dry after this operation, since there are numerous accessory lachrymal glands (glands of Waldeyer and Krause) opening on to the superior fornix. 2. _A sinus._ The wound may break down and a sinus may form at the site of the incision. These cases are nearly always of tuberculous origin and not infrequently have underlying bone trouble. They can usually be made to heal by the use of iodoform and scraping.