OPERATIONS FOR THE RELIEF OF LACHRYMAL OBSTRUCTION

DILATATION OF THE Ca.n.a.lICULUS

=Indications.= (i) Contraction of the puncta following marginal blepharitis, especially when a.s.sociated with ectropion.

(ii) Preparatory to syringing or probing.

(iii) To dilate a stricture of the ca.n.a.liculus.

=Instruments.= Nettleship's ca.n.a.liculus dilator (Fig. 163).

=Operation.= The operation is performed under adrenalin and cocaine, a little solid cocaine being rubbed in over the ca.n.a.liculus.

The lid is slightly everted and put on the stretch by pulling it downwards and outwards with the thumb. The depression caused by the punctum is seen on the top of a small elevation. The point of the dilator is entered vertically into the punctum and then turned parallel with the lid margin and pa.s.sed onwards with a steady pressure. At the same time it should be rotated between the finger and thumb, until the inner bony wall of the lachrymal sac is felt. The only difficulty which may be experienced is in entering the dilator into the punctum, owing to the small size of the latter. For this reason the fine point of Nettleship's dilator is more suitable than the form modified by Lang.

Even Nettleship's dilator is too large in a few cases, and here a large sharp-pointed pin is sometimes of use in defining the punctum before using Nettleship's dilator.

[Ill.u.s.tration: FIG. 163. Ca.n.a.lICULUS DILATOR]

SLITTING THE Ca.n.a.lICULUS

=Indications.= To enlarge the punctum and direct the entrance to the ca.n.a.liculus inwards. This is especially desirable before ectropion operations and for the removal of concretions (leptothrix) from the duct. In former days the ca.n.a.liculus used to be slit with the idea of pa.s.sing very large probes down the lachrymal duct; this has now been abandoned, since slitting the ca.n.a.liculus throughout its whole length, as is required for this treatment, does away with the capillary attraction.

[Ill.u.s.tration: FIG. 164. Ca.n.a.lICULUS KNIFE.]

=Instruments.= Dilator, ca.n.a.liculus knife (Fig. 164), straight iris forceps, sharp-pointed scissors.

=Operation.= It is usually performed on the lower ca.n.a.liculus. The eye is cocainized as in the previous operation and the patient is made to look up.

_First step._ The ca.n.a.liculus is first dilated. The knife is inserted for a short distance with the handle parallel to the lid margin. The lower lid being held on the stretch by the thumb, the handle of the knife is raised towards the brow, thus dividing the ca.n.a.liculus. The blade of the knife should be directed upwards and slightly backwards.

_Second step._ As the lips of the wound are liable to reunite, it is better to remove the posterior lip of the groove. This is performed by seizing the latter with forceps and dividing it with scissors. The entrance to the ca.n.a.liculus should be kept open by means of the dilator pa.s.sed twice a week for a month.

SYRINGING THE LACHRYMAL DUCT

=Indications.= (i) To test whether the lachrymal ca.n.a.ls are patent.

(ii) By constantly cleansing the sac and washing away all purulent discharge the mucous membrane may regain a more healthy condition, and so an obstruction due to an alteration in the mucous lining may be relieved. In cases with a purulent discharge a small quant.i.ty of protargol (10% solution) may be left in the sac after syringing.

[Ill.u.s.tration: FIG. 165. LACHRYMAL SYRINGE.]

(iii) The injection of adrenalin and cocaine into the sac before its excision.

=Operation.= The eye is cocainized and the patient made to look up. The punctum is everted by pulling down the lower lid. The ca.n.a.liculus is then dilated. The nozzle of the lachrymal syringe (Fig. 165) should be pa.s.sed until it is felt to impinge on the bony outer wall of the sac.

Withdraw the syringe slightly and apply gentle pressure to the piston.

The fluid will either regurgitate through the upper ca.n.a.liculus or, if the duct be patent, pa.s.s down into the nose and so into the throat.

=Complications.= If too forcible syringing be used extravasation of the fluid may take place. This is accompanied by pain and swelling in the lachrymal region. It usually subsides under hot fomentations, but suppuration and even cellulitis of the orbit have been known to occur.

PROBING THE LACHRYMAL DUCT

=Indications.= (i) In cases of congenital lachrymal obstruction due to debris blocking the duct.

(ii) When syringing has failed to bring about a cure, a probe may be pa.s.sed once or twice to see if dilatation causes any improvement. It is especially useful in children.

(iii) As a preliminary to the insertion of styles.

Various forms of probes are employed, those of Bowman being in general use. Too fine a probe should not be used, otherwise a false pa.s.sage is liable to be made.

=Operation.= This is performed under adrenalin and cocaine, which should be injected into the lachrymal sac.

The lower punctum is dilated and the probe pa.s.sed parallel to the lid margin until it is felt to impinge upon the lachrymal bone. Keeping the point applied to the bone, the handle of the probe is rotated upwards through rather more than a quarter of a circle and pa.s.sed by a gentle pressure downwards and slightly outwards into the duct, keeping the point of the probe close to the bone the whole way. The direction of the probe after entering the duct should be downwards, outwards, and backwards in the direction of the first molar tooth on the same side.

The backward direction of the duct is much more marked in young children than in adults.

=Complications.= A false pa.s.sage may be made into the antrum of Highmore. If such an accident should occur, no further attempt should be made to pa.s.s a probe for a few days until the wound has healed.

THE INSERTION OF STYLES

A few surgeons still insert styles into the lachrymal duct with the idea of continuous dilatation. The hollow styles used by Bickerton are the ones most frequently employed.

=Instruments= for dilating, slitting the ca.n.a.liculus, probing, and styles. Also Stilling's knife.

=Operation.= A general anaesthetic is desirable.

_First step._ The ca.n.a.liculus is dilated and slit up, the posterior lip being removed (see p. 29).

_Second step._ The duct is dilated by probing (_vide supra_) or enlarged by pa.s.sing Stilling's knife down it.

_Third step._ A style is pa.s.sed down the dilated duct. The lower end of the style should rest upon the floor of the nose, otherwise there is a tendency for the style to slip into the duct and disappear. Care should be taken that the upper end does not rub on the globe. Styles should generally be left in position from three to six months. A style should at first be made of lead wire and moulded until a suitable pattern is obtained, from which a hollow gold style can be made subsequently.

=Complications.= 1. _Dacrocyst.i.tis_ may follow the insertion of a style, which should then be removed until the inflammation has subsided.

2. _The style may slip down the duct._ If this should occur an attempt should be made to grasp it through the slit ca.n.a.liculus. The lower end may present in the nose and the style can then be withdrawn with forceps. Occasionally styles lodge in the antrum of Highmore, in which case they must be removed after localization by the X-rays through an opening from the mouth above the canine tooth.

OPERATIONS FOR THE OBLITERATION OF THE Ca.n.a.lS

When syringing and probing have failed to relieve the lachrymal obstruction, one of the following operations for the obliteration of the lachrymal pa.s.sages may be employed.

OBLITERATION OF THE Ca.n.a.lICULI

=Indications.= In cases of lachrymal obstruction in which an immediate operation upon the globe is required.