A System of Operative Surgery, Volume 4 (of 4)

by Unknown

5. Toilet of the wound.

Fig. 94. Lens Extraction. Showing the position of the hands when making a section upwards with a Graefe’s knife.

First step. The incision. The surgeon, standing behind the patient’s head and holding the knife with the edge directed upwards, in the right hand for the right eye and in the left hand for the left, fixes the eye with a pair of forceps held in the other hand, by grasping the conjunctiva below and to the inner side as close to the limbus as possible (Fig. 94). Most continental surgeons stand in front of the patient and cut upwards. The point of the knife is then passed on the flat into the anterior chamber from the outer side, 1.5 millimetres behind the corneo-sclerotic junction.

Fig. 95. The Knife entering the Anterior Chamber in Cataract Extraction. The point of the knife is directed downwards and inwards.

Fig. 96. Making the Counter-puncture in Cataract Extraction. The counter-puncture is shown completed.

It is first directed downwards and inwards until the chamber is penetrated (Fig. 95). The knife-point is then directed horizontally and passed across the anterior chamber in a line parallel with an imaginary tangential line across the top of the cornea. The counter-puncture is then made, the knife emerging 1 millimetre behind the corneo-sclerotic junction (Fig. 96). In making the counter-puncture the beginner is apt to go too far back in the sclerotic owing to the angle of the chamber being placed behind the limbus; he should therefore aim for a point about 1 millimetre inwards from the limbus. The knife is next made to cut upwards by a sawing movement so that a flap is formed of corneal tissue about 3 millimetres in breadth (a breadth and a half of a new Graefe’s knife), the upper margin being at the corneo-sclerotic junction. When the corneal flap has been made, the knife should lie beneath the conjunctiva, from which a flap about 3 or 4 millimetres in length should be formed. The knife-edge is then turned forward and made to cut its way out. In making the section, care must be taken not to prick the patient’s nose or eyelid with the point of the knife, as it may cause him to move his head with disastrous results. This is more likely to happen with patients who have sunken eyes.

Fig. 97. Incision and Iridectomy in Cataract Extraction.

Second step. Iridectomy. The patient is made to look downwards. A pair of iris forceps are inserted, closed, into the anterior chamber, opened, and the iris grasped near its root, and withdrawn. The piece of iris is then removed with the iris scissors, dividing it parallel with the incision as close to the eye as possible (Fig. 97). If the conjunctival flap hinders the insertion of the iris forceps into the anterior chamber, it may be turned forward over the cornea with the point of the closed forceps.