=Operation.= Under cocaine. Fine sutures armed with a small curved needle are pa.s.sed beneath both the upper and lower can[al]iculus and tied so as to include them in the ligature. Permanent obliteration may be caused by the destruction of the lining membrane with the actual cautery.

EXCISION OF THE LACHRYMAL SAC

=Indications.= (i) For mucocele in cases of lachrymal obstruction which have failed to yield to other treatment.

(ii) In all cases of tuberculous disease of the sac.

(iii) For a recurrent lachrymal abscess after subsidence of the acute inflammation.

(iv) For hypopyon ulcer a.s.sociated with lachrymal obstruction.

(v) Before operation on the globe in cases of lachrymal obstruction.

(vi) For lachrymal fistula.

=Instruments.= Small scalpel, forceps, Muller's speculum (Fig. 166), Axenfeld's retractor (Fig. 167), straight scissors, horsehair sutures.

=Operation.= Haemorrhage is the most troublesome part of this operation; it is best controlled by injecting adrenalin (made from the dried gland, ?j, and ?j of water) and cocaine, 10%, into the sac a quarter of an hour before operating. Swabs on the end of a gla.s.s rod dipped in adrenalin and cocaine may also be used during the operation. A general anaesthetic is desirable, but many surgeons perform the operation under local anaesthesia, produced by injecting 5% cocaine with 1 in 1,000 adrenalin into the tissue surrounding the sac; but the latter plan has the disadvantage that the mixture may cause severe toxic effects, and the patient usually experiences some pain while the upper portion of the incision is being made and the lower end of the sac is being divided.

_First step._ The internal tarsal ligament is first defined by putting the lids on the stretch. An incision should be made, 15 millimetres in length (5 millimetres of which should fall above the tarsal ligament), backwards and inwards directly over the lachrymal sac. Muller's retractor is then inserted to retract the wound laterally, the hooks being made to engage the margins of the incision by means of forceps.

The superficial fascia and the fibres of the orbicularis muscle are then divided. The internal tarsal ligament in the upper part of the wound, together with the glistening deep fascia, is exposed and divided carefully so as not to injure the lachrymal sac, which is found directly beneath it (Fig. 168).

[Ill.u.s.tration: FIG. 166. MULLER'S RETRACTOR FOR EXCISION OF THE LACHRYMAL SAC.]

[Ill.u.s.tration: FIG. 167. AXENFELD'S RETRACTOR FOR EXCISION OF THE LACHRYMAL SAC.]

_Second step._ With scissors the sac-wall is then separated from the deep fascia which encloses it, first externally and then internally, the ca.n.a.liculi being divided. Axenfeld's retractor is then inserted in the longitudinal axis of the wound (Fig. 167). The middle of the sac is grasped with forceps and pulled forward, and the top of the sac is defined and detached. This is frequently difficult owing to the troublesome haemorrhage which often occurs. The sac is pulled well forward, and the posterior wall is separated, the neck of the sac being divided as far down the duct as possible by means of scissors. A large probe is pa.s.sed down the duct into the nose. Some surgeons remove the periosteum of the lachrymal bone as well as the sac, which is unnecessary. The wound is closed by three sutures, the middle one including the divided ends of the internal tarsal ligament. A firm dressing should be applied so as to keep the walls of the cavity in contact. In tuberculous cases it is desirable to curette the lower end of the duct after removal of the sac. The st.i.tches are removed on the seventh day.

=Complications.= These may be immediate or remote.

=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.

[Ill.u.s.tration: FIG. 168. EXCISION OF THE LACHRYMAL SAC. Showing the internal tarsal ligament in the upper part of the wound with the sac lying beneath.]

[Ill.u.s.tration: 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 ca.n.a.liculi. 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 pa.s.ses 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 sc.r.a.ping.

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 dema 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.

OPERATIONS UPON THE LACHRYMAL GLAND

REMOVAL OF THE PALPEBRAL PORTION

=Indications.= For obstinate epiphora after removal of the lachrymal sac.

=Instruments.= Fixation forceps (two pairs), two sharp hooks, strabismus scissors, suture.

[Ill.u.s.tration: FIG. 170. EXCISION OF THE PALPEBRAL PORTION OF THE LACHRYMAL GLAND. The lid is doubly everted and the gland is dissected out from within outwards.]

=Operation.= Usually performed under adrenalin and cocaine.

_First step._ The upper lid is doubly everted. The eversion is best carried out by holding the singly everted lid between forceps and then re-everting it; the forceps are then given to an a.s.sistant to hold. With a syringe a few drops of 5% cocaine are injected through the conjunctiva into the area to be operated upon.

_Second step._ The gland is seen beneath the conjunctiva at the outer part of the upper fornix, seized with forceps, and drawn forwards. A horizontal incision is made with scissors through the conjunctiva, which is dissected backwards. The edges of the wound are then held apart by means of sharp hooks (Fig. 170).

_Third step._ The gland, which is seen as a nodule, is drawn forward with forceps. By means of the scissors the gland is separated from its attachments along its whole length, starting on the inner side, the wound being subsequently closed with a few points of catgut suture.

REMOVAL OF THE ORBITAL PORTION

=Indications.= It is usually undertaken for tumours (endotheliomata, &c.) and retention cysts.

=Instruments.= Knife, artery and dissecting forceps, retractors, ligatures.

=Operation.= Performed under a general anaesthetic.

_First step._ An incision, three inches long, is made through the skin immediately below the outer third of the orbital margin. The underlying orbicularis palpebrarum is divided, and the orbital fascia covering the gland is defined and incised.

_Second step._ The gland is first separated from the periosteum of the depression in the bone in which it lies, and is drawn forward and carefully dissected out from the lid. The wound is then closed with sutures.

=An abscess in the lachrymal gland= should be opened by an incision similar to, but not so long as that in the above operation.

OPERATIONS UPON THE ORBIT

EXPLORATION OF THE ORBIT (KRoNLEIN'S METHOD)