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.
3. Recurrence of the mucocele or lachrymal abscess. Occasionally the mucocele may re-form, or an abscess result after removal of the sac. This is due either to a piece of sac-wall being left behind, or to the relining of the cavity with epithelium from the cut end of the duct. It is particularly liable to occur in cases of a tuberculous nature. Firm pressure with the dressings after the operation is the best method of preventing the cavity relining with epithelium. If the condition has arisen, the pseudo-sac should be excised.
OPENING A LACHRYMAL ABSCESS
Indications. Lachrymal abscess is due to an inflammation around the sac-wall through which infection of the cellular tissue has taken place. The abscess should not be opened until pus is present, as even considerable swelling and œdema will often subside without suppuration; this is usually about the end of the third day. Further, if the opening be made too soon, the inflammation takes considerably longer to subside.
Instruments. Beer’s knife, forceps, and probe.
Operation. Usually performed under gas. An incision is made over the lachrymal sac and is carried downwards and inwards to the bone by a single puncture of the knife. The pus is evacuated, and the cavity stuffed with gauze, which should be changed daily for the first three days. Hot fomentations should be applied. As soon as the swelling has subsided, the lachrymal obstruction should be treated by one of the methods previously described.