Part 38

When cataract is spontaneous, and vision not altogether lost, the patient being able to distinguish bright objects, though unable to direct his steps or follow his avocation—when the pupil is quite sensible to the application or abstraction of light, or to the use of belladonna, &c.,—when all the external parts are sound, the cornea clear, the chambers of the proper size, and no reason to suspect that the retina is affected—the prognosis in regard to the effects of operation is good. When, on the contrary, the organ or the constitution is not sound—when the patient is irritable in habit or temper, or subject to gouty, rheumatic, or catarrhal complaints—when headache has preceded the opacity, and vision is gone, or nearly so, with flashes of light seeming to pass before the eyes—the prognosis is very unfavourable. But even total blindness must not always be considered as an indication of operation proving useless, for sometimes the retina recovers its sensibility after removal of the cataract, and thus sight has been restored in very hopeless cases. There is no objection against operating, though one eye only is affected. By some, operation is recommended as prudent, with a view of preventing the opposite eye from suffering by sympathy; whilst others consider it more safe to refrain from operating, lest violent inflammatory action should follow, and, by extending to the other eye, cause disease there. However, when the cataractous eye does not present such appearances as forbid operation, I conceive it both prudent and safe to remove the obstruction to vision, provided after-treatment is carefully attended to, and all untoward symptoms actively combated as soon as they appear. There is still a considerable difference of opinion on the subject; but the patient, being anxious to get rid of an inconvenience and deformity, often decides for the surgeon. When both eyes are cataractous, a question arises as to operating on both eyes at once. From my own experience I should say, that both eyes ought not to be operated on at one time: if they are, there is great risk of violent inflammation being established, and of the operation failing to restore vision. Immediately after one eye has been operated on, the other becomes very unsteady, and is altogether in an unfavourable state for operation; and, if interfered with, the chance of a happy result is but slight. But by operating on each eye at different times, much less risk is incurred, and the chance of success is doubled.[30] Cataract may be operated upon at all ages, excepting infancy and the period of dentition. In congenital cataract, the eyes acquire an uncontrollable rolling motion, and, if operation be delayed till the patient has attained a considerable age, such motion cannot be afterwards prevented. In such cases, therefore, the disease should be attacked as soon as dentition is completed, for then an operation can be undertaken with as little risk of injury to the organ as at a more advanced age; and a child of twenty months or two years is unconscious of what is intended, and can be more readily secured than at any after period; besides the best period for education is lost if an operation be not done early.[31]

Cataract is not remediable but by surgical operation. It may be removed altogether by incision of the tunics of the eye, and extraction of the opaque body; or by the introduction of a needle, it may be displaced from the axis of vision, or so disturbed as to be acted on and removed by the absorbents.

Operation with the needle is more generally applicable than that with the knife, and is more easily performed. But much mischief may be done with a needle, if the operator be not both cautious and dexterous; by unskilful use of it many eyes have been lost.

In operations for cataract on the adult, the patient, having the eye which is not the subject of operation covered, may be seated on a low chair, opposite and near to a north window, in order that clear light may be obtained. His head is supported on the breast of an intelligent assistant standing behind. The upper eyelid is raised by the assistant’s fore and middle fingers of the left or right hand, applied so as to stretch the lid over the bulb; and the other hand is placed under the patient’s chin, to steady the head. The eye may be very well fixed by the fingers of the right or left hand of the operator himself. He is, in that case, more conveniently placed behind or above the patient’s head. The use of a speculum, for elevating the lid or fixing the ball, is seldom admissible; and, if the eye be so unsteady or sunk as to require it, the surgeon ought not to attempt extraction. No one method can be exclusively followed; by a man of judgment, experience, and skill, the operation will be varied according to circumstances.

The operation may be performed with the needle. The cataract is either _depressed_ or _reclined_, and is then said to be couched. Depression is preferred by many good authorities in surgery. The needle is introduced at a line—or a line and a half, so as to avoid the ciliary processes—from the junction of the cornea with the sclerotic, towards the external canthus, and below the transverse diameter of the eye; and the opaque lens, if solid, is entangled with the point of the instrument, and pushed into the lower part of the ball. Thus the opaque body is removed from the axis of vision, so as not to obstruct the passage of rays of light to the retina; and, in successful cases, it is highly probable that the lens, after being detached and displaced, is altogether removed by the absorbents. Violent inflammation occasionally takes place after the operation, followed with destruction of the eye from suppuration; or the iris becomes paralytic; or the pupil closes, and sight is gradually lost; or the cornea becomes flaccid, with congestion of the vessels and turbidity of the humours. The needle should be of a conical form, thickest towards the handle, so as to prevent the humours from escaping during its introduction. It should also be straight, excepting a short curvature of its point, rather slim than otherwise, and not longer than from an inch to an inch and a quarter. The extracts of belladonna or stramonium should be used in all cases, previously to determining upon operations, in order to ascertain the state of the humours, the size of the cataract, and whether adhesion of the iris to the capsule of the lens exist or not. Dilatation so produced is allowed to disappear almost entirely before the operation is proceeded in. It is sometimes necessary to steady the eye by means of a speculum, and the wire one of Pellier is the best. By pushing the needle, held like a writing pen, gently forwards, and towards the inner canthus, in a direction almost parallel with the iris, its point is seen in the posterior chamber, opposite the pupil. The instrument is then fixed in the opaque lens, and the cataract is depressed obliquely downwards; the needle is disentangled by a gentle twisting motion, and then withdrawn in the same direction as it was entered. Before depressing, it is necessary to lacerate the capsule of the lens, and this is accomplished by giving the needle a rotatory motion, and moving its point in different directions; the anterior portion of the vitreous humour is at the same time disturbed. Laceration of the capsule may be too great, and allow the lens to escape entire into the anterior chamber; inflammatory action is in consequence excited, and subsides only when an opening has been made in the cornea, and the offending body extracted. If the cataract rise to its original situation on withdrawing the needle, it should be again depressed, and kept down by the instrument for a short time; and when the needle is then removed, its point should be very carefully disentangled. The lens is said frequently to regain its usual situation, a considerable time after the operation; but in many such cases, the opacity in the pupil is not occasioned by the lens, but by the capsule having become opaque. It is said to have arisen, when very solid, twenty or thirty years after depression; and that in many cases no absorption of it occurs. When the vitreous humour has become disorganised, the lens often floats about, rising and falling with the motions of the head.

In _reclination_, the point of the needle is placed on the upper and anterior surface of the lens; and by raising the handle, and pushing the point slightly forward towards the inner part of the eye, the lens is removed from the axis of vision, placed inferior to it, and has the relative situation of its surfaces changed—its anterior surface becoming the upper, and the posterior the under; the superior, posterior; and the inferior, anterior.

Solid cataracts only can be depressed or reclined. When a cataract is fluid, it is sufficient to puncture, or lacerate slightly, the anterior part of the capsule; as then the opaque contents will be diffused through the aqueous humour, and soon removed by the absorbents. Should the capsule become opaque, after the removal of its contents, the needle must be at a future period introduced; the capsule is to be lacerated and reduced to minute shreds, so that it may escape into the anterior chamber. In the soft or caseous cataract, displacement is not easily effected; and the surgeon must rest satisfied with exposing a part or the whole of it to the action of the aqueous humour.

The above operations may be had recourse to when—from diminution of the anterior chamber, adhesions of the iris, a morbid state of the pupil, and the temper of the patient—extraction cannot be attempted. When the cataract is small, it is immaterial how it is displaced; when large and solid, reclination is to be preferred. The operator is obliged to decide as to the mode of finishing the operation, after he has introduced the needle, and thereby ascertained the consistence of the cataract. If it is so soft as to permit the needle to move in all directions, it is impossible to displace it; it must be broken up, and left in situ.

In the mode of operation termed _keratonyxis_, the needle is introduced through the cornea, about two or three lines from its margin,[32] and the cataract is either depressed or broken up for solution. Depression through the cornea is, however, an operation not to be recommended, as the surgeon has much less command over the motion of his instrument, necessary in this form of procedure, than where it is introduced through the sclerotic coat. The pupil is previously dilated by belladonna, and the dilatation should be continued for some time afterwards. The puncture may be made at any part of the corneal circumference; it soon heals, and leaves no scar. The operation can be performed without much disturbance of the organ, and it is applicable when the cataract is soft or fluid, as in children, or its consistence doubtful. Young subjects should be placed recumbent during the operation, and rolled up in a sheet, so that they can have no command over their limbs.

_Extraction_, in favourable circumstances, and in dexterous hands, is a beautiful operation, and most satisfactory; but ought not to be undertaken unless the surgeon has perfect confidence in himself. It can be resorted to only in adults, great steadiness on the part of the patient being absolutely necessary. The case, too, must be judiciously chosen. The conjunctiva must be sound, and indeed almost no operation on the eye should be undertaken unless this membrane is in a healthy condition; the cornea should be transparent in every part—the anterior chamber of a proper size—the pupil regular—the iris steady, and not protruded—and the cataract solid; there should be no rolling motion of the eyeball, and no adhesions of the iris. I repeat, the iris should be steady, for a tremulous motion of it indicates disorganisation and fluidity of the vitreous humour; in such a case, the humour can with difficulty be prevented from escaping; or the lens may fall into the bottom of the eye, and all efforts to remove it will then prove abortive. And though such descent of the lens should not occur, still the organ is in a very unfavourable state for operation, being apt to become affected with deep inflammation, followed by complete amaurosis, or by closure of the pupil. The patient is prepared for the operation by moderate living, and attention to the secretions and digestive organs, for some time previously; and after the operation leeching may be necessary either as a precautionary measure, or when inflammation has occurred. Immediately before having recourse to any of the operations for cataract, a small blister may be applied with advantage behind one or both ears, and kept open for some few days, as a precautionary measure against inflammatory action in the organ operated upon.

The operator is usually seated immediately before the patient, and so that his breast may be on the same level with the patient’s head; if not ambidextrous, he may often be obliged to assume very awkward attitudes. The recumbent position, however, is preferred by many operators, and has the great advantage in the superior steadiness of the head of the patient. The hand of the surgeon may also be rested on the back of the couch, as, if ambidextrous, he will invariably take his position behind the patient, in order that he may have the command of the upper eyelid in his own hands. The incision is made either in the lower or upper half of the cornea. The knife should have a very keen edge, and become gradually broader and thicker, from its point backwards: in using a narrow instrument there is danger of the aqueous humour escaping. The best knife is Beer’s, well made. The light must be good, the patient’s head completely steadied, the eye well fixed by the fingers of the assistant, and the other one covered by a bandage. No speculum should be employed, and the pupil should not be dilated by belladonna. The surgeon, supporting his elbow on his knee, or resting his fingers on the cheek of the patient, holds the knife like a writing pen—in the right hand, if the left eye is to be operated on, in the left, if the opposite (that is to say, if he sits before his patient: if, however, he places himself behind, this must be reversed)—and ascertains the steadiness of the organ by touching the cornea gently with the side of the knife. The cornea is punctured about a line from its margin, and near the outer extremity of its transverse diameter, the point of the knife being directed towards the centre of the eye, lest it should enter between the laminæ. The knife is then passed through the anterior chamber, with its side parallel to the iris, and its point is brought out at that part of the cornea exactly opposite to where it entered: transfixion is thus completed, and by pushing the knife steadily forward, without any sawing motion, a semicircular section is effected. As soon as transfixion is accomplished, the operator has complete command of the eye, and all pressure should be taken off—the assistant should now merely keep the eyelid raised. Should the edge of the knife not come easily through the cornea, its passage maybe assisted by pressure with the finger-nail.

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.

In those cases where the natural pupil remains along with a still transparent lens, while vision has been destroyed by a central opacity of the cornea, the use of sharp and pointed instruments is forbidden. Sharp hooks or scissors would endanger wound of the crystalline, and the case becoming complicated with traumatic cataract. The blunt hook, as proposed and used by Mr. Tyrrell, is here to be preferred. A small opening is made through the cornea, as the most convenient part, and the hook carefully introduced and entangled in the existing pupil: the iris is then drawn to the corneal wound, and either left entangled in the section, or removed by a pair of curved scissors. A pupil is thus formed opposite to the remaining transparent portion of the cornea.

III. _Corodialysis_, or separation of the iris from its ciliary attachments, is the method most easily performed, and most generally applicable. The eye is fixed either with the fingers or with a speculum; and a curved needle, perhaps more curved than that usually employed for cataract, is introduced either behind or before the iris, and at the upper, outer, inner, or lower part of the ball, as circumstances may require. An artificial pupil at the lower part is by much the most useful; but, if the lower part of the cornea is opaque, it must be made opposite to the inner or outer clear part. The point of the needle is entangled in the attached margin of the iris, and by raising the hand quickly, and partially withdrawing the instrument, the connexions are separated to a sufficient extent. Effusion of blood into the chamber, and to a considerable extent, follows these proceedings; and it is only after its absorption that it can be ascertained whether benefit is likely to result or not. After all these operations, inflammatory action requires to be kept down by antiphlogistic measures, abstraction of blood, purgatives, antimonials, and, perhaps, mercurial preparations. It is questionable whether belladonna can be useful in preventing closure of an artificial pupil.