Elements of Surgery

by Robert Liston

After the pupil has been allowed to dilate, by covering the eye for a few seconds with the hand, the capsule must be opened sufficiently for the escape of the lens. The eyelids are gently raised, a fine curved needle, or curette, is introduced through the incision, and by it a crucial wound is made in the capsule. The lens is then either entangled in the point of the needle and withdrawn, or very gentle pressure is made on the globe, so as to force out the lens; and, should it not readily pass through the wound of the cornea, it can be removed from the anterior chamber by a small scoop. After removal, the eye is allowed to rest; then careful examination is made; and, if any opaque substance remain, it is extracted by the needle or scoop. If the capsule is opaque, it must be taken away along with the lens. Before closing the eyelids the corneal flap should be carefully adjusted, and any matter lodged between the divided surfaces removed: loose eyelashes are to be taken away, inverted ones should be previously extracted, and the margin of the lower lid should be so placed as not to disturb the flap.

In transfixion, the point of the knife should not be brought out too low, nor too much towards the centre of the cornea; and care should be taken to avoid entanglement of the iris. When the iris falls forward so as to come under the edge of the knife, and be in danger of division should transfixion be proceeded in, pressure may be made on the cornea, so that the remaining aqueous humour may repress the iris from its untoward situation; or the knife may be withdrawn, and the operation delayed till the eye has become quiet, and the inflammation, if any, has subsided; or the incision may be completed with a blunt-pointed narrow knife, or with probe-pointed scissors. Division of the capsule by the point of the knife during transfixion has been practised; but it is an unsafe, though dexterous, measure. In opening the capsule care should be taken not to separate its attachments, otherwise it will become opaque, and thereby passage of light to the bottom of the eye will be again obstructed. Neither should much pressure be used for extrusion of the lens; for, in the case of a large and firm cataract, the iris may be lacerated, and the humours escape. When any of the vitreous humour has escaped, in consequence of its cells having been broken down, and its tenacity diminished, the eye soon fills again, but good vision is hardly to be expected.

After the operation, applications to the eye should be very light; a rag dipped in cold water, and renewed occasionally, is sufficient. All stimulants of the organ, as light, should be avoided, and antiphlogistic treatment adopted. Should violent pain supervene, bleeding, both local and general, and other means for subduing inflammatory action, must be had recourse to. The eyelids should not be raised or exposed for at least three days, unless in extraordinary circumstances. Belladonna is of use when gradual contraction of the pupil occurs. In very favourable cases, vision is completely restored in the eye; in others, the functions of the two eyes do not correspond, and vision is confused: the patient requires to wear a convex glass before the one which has been operated on.

The operation of making an artificial pupil is far from being uniformly successful, and ought not to be had recourse to unless vision is entirely lost, or so much impaired as to be insufficient for the guidance of the patient’s steps. It is necessary on account of central opacity of the cornea—leucoma with entanglement of the iris—and entire

closure of the pupil, or diminution of it, with concealment of the remainder by corneal opacity. It may be required after badly performed extraction of a cataract, the iris being entangled in the scar of the incision, at a distance from the junction of the cornea with the sclerotic; or on account of closed pupil from inflammation, when, perhaps, the cornea is all clear. The operation is varied according to the size of the anterior chamber, the presence or absence of the crystalline lens, the extent of sound cornea, and the condition of the iris. Interference is useless when disease of the retina is suspected, from the extent of the previous disease—from violent inflammation, with or without discharge of part of the contents of the eyeball. Three distinct methods of operation are pursued.

I. Simple division of the iris, or corotomia, may be practised when the iris is stretched, as after extraction. It is performed by introducing a small knife, like a needle, through the anterior or posterior chamber,—the surgeon being in this regulated by the size of the anterior chamber and the presence or absence of the lens,—pushing

its point through the iris, or cutting that membrane vertically, horizontally, or both, to an extent sufficient for the transmission of light. If the anterior chamber be of its natural size, a small opening may be made in the cornea with a cataract knife, or a double-edged broad and thin one; and through this opening small scissors may be introduced for division of the iris.

II. Corectomia, or cutting out a portion of the iris, so as to make the opening oval, square, or angular. This is performed by introducing, through an aperture in the cornea, scissors and forceps, or hooks, double or single—the latter to lay hold of the iris, the former to divide it. After the escape of the aqueous humour, a portion of the iris may be made to protrude; and, on the projecting portion being cut off, the membrane, with a proper opening in it, regains its natural situation, in consequence of discharge of the humour from behind. This operation is applicable only in few cases; the whole, or the greater part, of the cornea must be clear, and the anterior chamber not diminished in size, so that sufficient room may be afforded for the introduction of instruments between the iris and the concave surface of the cornea.