Galabin’s Broad-ligament NeedleFig. 69. Galabin’s Broad-ligament Needle (right).
Jessett’s Broad-ligament NeedleFig. 70. Jessett’s Broad-ligament Needle.
The uterus is now suspended in the pelvis by the attachments of the broad ligaments only; the next step consists in ligaturing and dividing these. The cervix is drawn over towards the patient’s right side by an assistant, so as to expose the base of the left broad ligament. Additional space is gained by drawing aside the left wall of the vagina by means of a retractor. By passing the left index-finger behind the broad ligament the tube and ovary can be easily felt, and if necessary the bent finger can pull them down for inspection; the finger is then placed beside the cervix below and behind the base of the broad ligament. A Galabin’s or Jessett’s (Fig. 70) needle, carrying a stout silk suture, is passed through the ligament from before backwards, on to the tip of the finger (Fig. 71).
Vaginal Hysterectomy
Fig. 71. Vaginal Hysterectomy.The patient is in the lithotomy position, the vaginal incisions have been made and the peritoneal cavity opened. The left broad ligament is exposed, and a Galabin’s needle threaded with silk is being passed from before backwards on to the index-finger of the operator’s left hand inserted into the peritoneal cavity. (Semi-diagrammatic, from a photograph.)a, a', a''. Retractors.c.Cervix.p.Supravaginal cervix denuded of its coverings.ut.Uterine artery.b.lig.Broad ligament.n.Galabin’s needle.v.Volsella.
a, a', a''. Retractors.c.Cervix.p.Supravaginal cervix denuded of its coverings.ut.Uterine artery.b.lig.Broad ligament.n.Galabin’s needle.v.Volsella.
The ligature should be passed about one-third of an inch up the broad ligament. It is then tied tightly and the ends left long and drawn aside. The segment of broad ligament included in the ligature is divided as near the uterus as is justifiable; in carcinoma of the cervix at least half an inch from the disease should be allowed. Care must be taken at this stage to avoid injury to the ureters; these lie about one inchdistant from the cervix; consequently all ligatures must be passed as near the cervix as possible compatible with being clear of the disease.
A second ligature is now passed through the broad ligament above the first and then a third, and more if necessary. The second generally includes the uterine artery, which can always be recognized by its strong pulsation under the finger; the third ligature will control the Fallopian and ovarian arteries. After the arteries on the left side have been secured and divided, attention is directed to the right broad ligament. The cervix is drawn over to the left side, the fundus delivered, and the upper portion of the right broad ligament is dealt with in a similar manner, but from above downwards. If the ovaries and tubes are diseased, they can now be removed by piercing the pedicle and tying the stump in the usual way.
The uterus having been extirpated, the next step consists in dealing with the wound. First, all bleeding is stopped, and the wound is swabbed clean and dry. The ligatures on either side are tied in two bunches and the ends cut off just within the vagina (Fig. 72). The anterior and posterior flaps of peritoneum are united with a few catgut sutures passed by means of Schauta’s needle-holder (Fig. 73); the walls of the vaginal vault are treated in a similar fashion, leaving a circular orifice in the median line into which gauze can be inserted for the purpose of drainage.
Vaginal Hysterectomy
Fig. 72. Vaginal Hysterectomy.Final stage.The uterus has been removed, and the peritoneal flaps are in process of suture.a, a', a'', a'''.Retractors.f, f'.Spencer Wells forceps attached to the anteriorand posterior vaginal flaps.p.Circular orifice left open in the peritoneal flapsfor insertion of gauze drain.sp.Stump of left broad ligament with bundle ofligatures (l).cl.Clitoris.l.m.Labium majus.u.Urethra.
a, a', a'', a'''.Retractors.f, f'.Spencer Wells forceps attached to the anteriorand posterior vaginal flaps.p.Circular orifice left open in the peritoneal flapsfor insertion of gauze drain.sp.Stump of left broad ligament with bundle ofligatures (l).cl.Clitoris.l.m.Labium majus.u.Urethra.
Schauta’s Needle-holderFig. 73. Schauta’s Needle-holder.
Some operators prefer to control the vessels in the broad ligaments by means of hæmostatic forceps instead of ligatures. Each broad ligament is clamped in three or more portions and the tissue between them and the uterus cut through. They must be allowed to remain in position for at least forty-eight hours, as recurrent hæmorrhage is possible if they are removed earlier. The only advantages of the forceps appear to be the rapidity with which the operation can be carried out, and the good drainage. The disadvantages are, that it is a somewhat unsurgical proceeding; there is often much pain from the nipping of the broad ligaments, and inconvenience from the presence of the handles between the labia; the intestines may be damaged; sloughing and risk of sepsis must be reckoned with.
After-treatment.The catheter should be used at first four times daily; the author recommends that the gauze should be removed at the end of twenty-four hours, but some operators retain it longer. The ligatures should be pulled upon a little daily after the seventh day, and they gradually cut their way through the tissues in their grasp. No vaginal douching should be administered until after the expiration of a week.
Vaginal hysterectomy for fibroids.This is not often called for. The operation is necessarily limited to fibroid uteri not exceeding in size a fœtal head. Uterine fibroids of such a size can usually be treated in other ways, either temporarily by curetting, or, if submucous, permanently by enucleation through the vagina. The operation is most suitable for uteri containing many small fibroids causing severe hæmorrhage which cannot be controlled by more palliative measures.
The vagina must be large enough to admit of delivery of the uterus through its lumen. Therefore, in virgins and nulliparæ, the abdominal operation is always to be preferred. In any case, if the vagina be too narrow, additional room may be gained by lateral vaginal section (seep. 148) or episiotomy.
The operation does not differ in technique from the removal of the uterus for carcinoma, already described. In some cases it may be preferable to bisect the uterus in the sagittal plane before removing it, after the cervico-vaginal attachments have been separated and the peritoneal pouches opened.
SECTION IIOPHTHALMIC OPERATIONSBYM. S. MAYOU, F.R.C.S. (Eng.)Assistant Surgeon, Central London Ophthalmic Hospital; Surgeon, The Children’s Hospital, Paddington Green
Operations upon the eye differ so widely from general surgical operations that it is necessary to say something of the preparations for them before passing on to their actual performance. Although not formidable in themselves, they require great accuracy and presence of mind; slight mistakes, such as too small an incision, may cost the patient his sight, which sometimes may be almost more important than life itself.
Most intra-ocular operations are performed without general anæsthesia; it is therefore important that the patient should be given confidence by talking to him during the operation, so that he may follow the instructions of the surgeon during its performance; loss of self-control on the part of the patient, movement of the head, screwing up of the eyes, &c., may lead to disastrous results, however well performed the operation itself may be.
The urineshould always be examined, especially in cases of cataract, as not infrequently this disease is associated with diabetes, and it is often advisable to treat the general condition before operation.
The bowelsshould be opened by an aperient the night before the operation, as it is desirable to keep them confined for the first two days afterwards, so as to avoid straining. During the first week after a major operation, when the patient is confined to bed, they should be evacuated in the supine position.
The best timefor operating, if possible, is the morning, as the patient has had a night’s rest and is less likely to lose self-control. Usually there is some pain after the cocaine has gone off, and the patient is better able to stand it during the daytime.
Anæsthetics.Generalanæsthesia should be induced in all patients with congested eyes, in small children, patients who are deaf, and those who show a want of self-control. Chloroform should be used for all intra-ocular operations, and should be given to the full surgical degree. It should be given on a towel or an inverted mask specially made for the purpose, a Junker’s inhaler being used during the time theactual operation is being performed. As the surgeon usually stands at the head of the patient, the anæsthetist should stand on the side away from the eye being operated on. The local use of cocaine in addition to general anæsthesia is indicated when operating on patients to whom it is advisable to give as little anæsthetic as possible.
Localanæsthesia is obtained by the use of a 4% solution of cocaine instilled four or five times before the operation at intervals of three minutes; a drop of the solution should also be instilled into the eye which is not being operated on, to prevent an accidental reflex stimulation of the conjunctiva and screwing up of the eyes. Adrenalin (1–1,000) may be used in conjunction with the cocaine; it is especially useful insquint operations, as it lessens the hæmorrhage. Eucaine and stovaine have been used, but are not nearly so satisfactory. Under ordinary circumstances the only pain felt during an intra-ocular operation is during removal of the iris; this is obviated to a great extent by instilling the cocaine at least 15 minutes before the operation is performed, so as to allow time for its diffusion into the anterior chamber. The patient should be warned when to expect the pain, so that he may not move; his self-control may be tested beforehand by pricking the nose with a pin.
Window of the Operating Theatre, King’s College HospitalFig. 74. Window of the Operating Theatre, King’s College Hospital.The windows are fitted with outside blinds so that either can be used separately, or the surgeon may stand in the angle and operate with his back to the light. A recess beneath the window allows the patient’s face to be brought close to the light on dark days.
The theatre.The theatre should possess, as far as possible, all the modern improvements found in an up-to-date general surgical operating-room. The light should proceed from a single large window, which, if possible, should face the north.The windowshould consist of a single pane of glass or of two panes forming the angle of the theatre; it should begin about 5 feet from the floor and should extend to the ceiling (Fig. 74). The advantage of an angular window is that it allows the operator to stand with his back to the light in the angle, and so enables onlookers to see. No top light should be allowed, as it produces a corneal reflection which may prevent the operator from seeing the position of his knife in the anterior chamber. Beneath the window there should be a recess for the end of the operating table, so that the patient’s face can be brought close to the window if necessary (Fig. 74). This recess is formed by building the main wall of the theatre further out than the window, which has to be supported by a transverse girder.
Bull’s-eye Electric Hand-lampFig. 75. Bull’s-eye Electric Hand-lamp.For use when artificial illumination is required.
The window should be fitted with outside blinds so that the theatre can be easily darkened for the operations, such as capsulotomy, which require the use of artificial light. The best artificial light is a small enclosed electric hand-lamp fitted with a bull’s-eye, by means of which the operation field can be brilliantly illuminated while the surrounding area is left in comparative darkness (Fig. 75). Failing this, a singlepowerful lamp with a ground-glass globe, placed in front of the patient, will serve, the rays of light being brought to a focus on the eye by means of a large convex lens of about + 10 D.
Forsquint operationsit is desirable to have a light fixed to the ceiling, directly over the head of the operating table, for testing the position of the eyes either by the reflection of the light from the surface of the cornea or by the Maddox rod test.
The operating tableshould be provided with a means of adjusting its height and the position of the head-piece, so that the patient’s head can be brought to about the level of the operator’s elbows when the latter is standing upright with his arms at his side.
After operationthe patient should be warned to lie still and not to strain in any way; he should be carried to bed and should lie on his back if possible. If a patient cannot sleep on his back it is better that he should lie on the sound side than be without rest. A length of bandage should be fastened round the wrist of the hand on the same side as the eye which has been operated upon, and should be attached to the bed so as to prevent the hand being put up to the eye during sleep. After major operations, such as those for cataract and glaucoma, the patient is confined to bed for ten days, during the first four of which the head should not be raised from the pillow, the bowels being evacuated while the patient is in the supine position; but old patients with a tendency to bronchitis or hypostatic pneumonia must be propped up in bed and allowed to get up earlier: in these patients it is better to perform the operation in the summer if possible. In old people and patients with a tendency to melancholia the mental condition must be carefully watched, as frequently they cannot stand the confinement to bed and darkness.
When operating upon the eye, a surgeon has to face the great difficulty that he is operating in an area which is not always aseptic, since it is practically impossible to render the conjunctival sac sterile. At the same time, the conjunctiva has been shown to be sterile in health in 25% of cases, pyogenic organisms (principally the staphylococcus albus) being found only in 15%; but, although these are usually not of a very virulent character, they are by far the most frequent cause of sepsis; ten cases of suppuration after operation which the author has examined were all due to this organism. After the methods of purification given below, this percentage is considerably reduced, so that, if due precautions are taken, the risk of sepsis is comparativelysmall. On the other hand, if conjunctivitis or lachrymal obstruction be present, the risks are enormously increased, especially in the latter condition owing to the frequent presence of the pneumococcus in the discharge, unless special precautions are taken. It is, therefore, of the utmost importance that every case should be examined for lachrymal obstruction before operation. Care should be taken also to see that there is no purulent discharge from the nose or any septic sores about the face.
Sepsis after intra-ocular operations manifests itself in one of two forms: either by suppuration, which usually ends in a rapid and complete destruction of the eye (panophthalmitis), or more rarely in less virulent cases by recurrent attacks of hypopyon associated with acute irido-cyclitis; or by a plastic irido-cyclitis, which may lead to slow disorganization of the eye, with always the possibility of destruction of the other eye by sympathetic cyclitis (sympathetic ophthalmia). Although these conditions are comparatively rare, owing to the improvement in modern aseptic and antiseptic methods, every surgeon of experience will meet with these disastrous complications; indeed it has been suggested that immunization with staphylococcus vaccine should be carried out before major intra-ocular operations, since infection is generally due to this organism.
The methods of purifying the eye before operation.On the second night previous to the operation the eye should be bandaged and examined the following morning for conjunctival discharge. If any be present, an examination for organisms should be made, and the operation postponed until the conjunctival condition has improved. In the event of the case being extremely urgent, the conjunctiva should be swabbed over with nitrate of silver (10 gr. to the oz.) immediately before the operation; some surgeons prefer 1–2,000 perchloride of mercury. If lachrymalobstruction be present, the sac should be thoroughly washed out with boric lotion and protargol (10%) injected. The canaliculi may be temporarily occluded subsequently (seep. 294). If the lashes be very long they should be cut short. Epilation is performed by some Continental surgeons, but is not practised in this country. Various forms of specula are made to keep the lashes out of the field of operation; of these, a modification of Lang’s is perhaps the best (Fig. 76).
Lang’s Eye SpeculumFig. 76. Lang’s Eye Speculum.Designed to hold the lashes away from the field of operation.
On the morning of the operation the lids should be thoroughly cleansed with soap and water, followed by 1–2,000 solution of perchloride of mercury, special attention being paid to the lid margins and lashes. The conjunctival sac should be washed out with boric lotion and a pad of cyanide gauze applied over the closed lid.
It has already been pointed out that the great danger in intra-ocular operations is sepsis. It is the aim and object of every ophthalmic surgeon to make such wounds into the globe as will become rapidly shut off from the conjunctival sac. Delay in the healing tends to the formation of a fistulous opening into the globe. This aperture in the continuity of the globe may lead either directly on to the surface or beneath the conjunctiva, subsequent inflammation in which may spread to the interior of the eye.
Undine for washing out the Conjunctival SacFig. 77. Undine for washing out the Conjunctival Sac.
Cocaineand other solutions used at the time and subsequently to operation should be sterilized. To ensure this the solutions should either be boiled immediately before use, or put up in drop bottles made in one piece with a long tapering neck, which is sealed off, and can be broken immediately before use. These bottles can be kept in an aseptic solution so as not to soil the hands of the surgeon.
The handsof the surgeon are purified. After the dressings have been removed, the patient’s head and the area surrounding the operation are covered with sterilized towels. In operations such as advancement, where sutures are used, it is desirable that the face should be covered with sterile muslin, with a hole cut in it for the eye, so as to prevent the sutures being contaminated from the skin of the face. The eyelids are again washed in 1–2,000 perchloride of mercury lotion, and the conjunctival sac is washed out with a strong stream of boric lotion or normalsaline by means of a sterilized irrigator or an undine (Fig. 77) which has been kept in a bowl of lotion.
Instruments.Non-cutting instruments are boiled for 15 minutes in distilled water and placed in a tray of 1–80 carbolic lotion. Some surgeons prefer to place the instruments in the tray without lotion on sterile wet lint, as this excludes infection from the surgeon’s hands due to the lotion running off them on to the instrument. Failing distilled water, a small quantity of soda may be added to the water used for boiling, but this has the disadvantage that a deposit is liable to form on the instruments. This may be obviated to a certain extent by not placing them in the solution until it is boiling. Cutting instruments should be sterilized by dipping them in liquefied carbolic acid (crystals dissolved by heating with 10% of water) for half a minute immediately prior to use and then into absolute alcohol to remove the acid; they are then placed in the tray. The greatest care should be taken to see that cutting instruments and needles do not touch the side of the dish. The edges and points should always be carefully tested immediately before sterilization on a drum covered with fine kid specially made for the purpose. The points should pass through the drum by the weight of the instrument held flat on the open palm; the cutting edge should also be tested. Scissors are best tested by cutting wet cigarette paper, special care being taken to see that the edges are good near the points. Immediately after operation the instruments should be boiled, and dried whilst hot in order to prevent rust.
Cataract ExtractionFig. 78. Cataract Extraction.The drawing shows the line of incision. Note the conjunctival flap.
The direction of an incisioninto the globe should be as oblique as is consistent with the object of the operation, so as to allow larger healing surfaces to come into apposition. With this object in view it is desirable that a conjunctival flap should be formed to all wounds wherever possible (Fig. 78). Further, owing to the extreme vascularity of the conjunctiva, as has been shown elsewhere,3wounds in it become firmly united after 48 hours. As a rule sutures are best avoided and are seldom required.
Position of the incisions.Corneal incisions are to be avoided, if possible, for the following reasons: firstly, the cornea being free from blood-vessels heals comparatively slowly; secondly, the wound is liable to become fistulous owing to the rapidity with which the epithelium grows down the side of the wound. On the other hand, incisions situated from 3 to 6 millimetres behind the limbus are liable to injure the ciliary body, and, in addition to irido-cyclitis being set up by the trauma, the iris or ciliary body will prolapse into the wound and prevent the union of its edges, with the result that sepsis may spread into the globe along the prolapsed portion of the uveal tract and set up an irido-cyclitis which may not only ruin the eye affected but may also cause a sympathetic irido-cyclitis in the other eye (Fig. 79).
Sympathetic OphthalmiaFig. 79. Sympathetic Ophthalmia.The exciting eye of a case following cataract extraction. The section shows the incarceration of the iris in the wound.
The site of election of an incisioninto the anterior part of the globe is therefore about 1 millimetre behind the limbus; that is to say, as near the cornea as is consistent with obtaining a good conjunctival flap to cover the wound in the globe (Fig. 78). When possible it is advisable to make all incisions in an upward direction for the following reasons: They are more easily performed; any deformities, such as an iridectomy, are hiddenby the upper lid; more perfect rest is obtained, as the wound is not exposed in the palpebral aperture, the eye being turned upwards when the lids are closed.
Cystoid Scar after Glaucoma IridectomyFig. 80. Cystoid Scar after Glaucoma Iridectomy.
The immediate danger of the passage of a knife into the anterior chamber of the eye is the wounding of the lens. To avoid this the point of the knife should be always kept superficial to the iris if a clear lens be present in the eye. After operation the chief danger is prolapse of the iris into the wound. This is best avoided at the time of operation by carefully replacing the iris with the spatula at the end of the operation, but unfortunately prolapse not infrequently occurs during the first few days owing to the reaccumulation of the aqueous in the anterior chamber and its sudden escape through the imperfectly healed wound as the result of straining or of some movement on the part of the patient; the iris may be carried into the wound with the escaping aqueous, and a fistulous opening or a scar may form subsequently (Fig. 80).
The less manipulation used consistent with the object of the operation the less likelihood is there of cyclitis following it. All instruments should be held lightly in the fingers, which should be as far as possible responsible for the fine manipulation required. The part of the hand not actually holding the instrument should be steadied on the face before the instrument is brought in contact with the eye.
When more than one operation has to be performed on the sameeye it is desirable that all ciliary injection after the first operation should have disappeared before the second is undertaken.
Dressings.A pad of sterilized wool, with a few layers of cyanide gauze moistened with 1–6,000 perchloride of mercury lotion next the closed eyelid, held in position by a bandage, is all that is necessary.
Bandaging.The bandage is started on the forehead over the affected eye and is carried in a direction away from the eye to be covered. A complete turn is made to encircle the head and is fixed with a pin. The bandage is then brought up beneath the ear and over the eye and fixed with pins on the forehead (Fig. 81). When absolute rest is desired, it is necessary to bandage both eyes. After intra-ocular operations this is desirable for the first three days. When pressure is desired, a figure-of-eight bandage should be used (Fig. 82). A useful bandage (Moorfield’s bandage) for occlusion of both eyes is made from stockinette, which fits closely over the eyes and nose and is fastened with tapes.
An Eye BandageFig. 81. An Eye Bandage.The first turn,A, encircles the head and is fixed with a pin. This portion of the bandage can be put on before the operation and obviates movement of the head. The turnBis then brought up below the ear and fixed with pins.
A Pressure BandageFig. 82. A Pressure Bandage.The first turn of a 1½-inch bandage encircles the head. It is then carried beneath the ear and over the head in a figure-of-eight. The final turn goes round the head and is fixed by a pin at the point of crossing of the previous turns.
The dressings should not be disturbed for at least 24 hours. The lids are then cleansed with 1–6,000 perchloride of mercury lotion, and the lower one is pulled down so as to allow the escape of tears and to see if any discharge be present. The upper lid should not be touched. If no discharge be present the eye is re-dressed. If discharge be present the conjunctival sac should be washed out carefully with boric lotion. Most wounds with conjunctival flaps are shut off in 48 hours, after which time it is advisable to wash out the conjunctival sac twice a day with boric lotion. Great care should be taken to see that no undue pressure is made on the globe. The patient should be warned not to screw up the eyes or strain whilst the dressing is being performed.
Surgical anatomy.The lens consists of fibres which are developed from cells originating in an inclusion of the fœtal epiblast. A normal lens is surrounded by a capsule, the anterior half of which is lined with a single layer of epithelial cells on its inner surface. In fœtal life the cells which line the posterior half of the capsule go to form the lens fibres, so that after birth the lens capsule is lined by cells only on its anterior surface. The lens capsule, which is deposited from the epithelial cells lining it, consists of a highly elastic membrane; small wounds in its continuity, therefore, gape widely. Throughout life the cells lining the capsule continue to become new lens fibres, but at the same time the bulk of the lens does not increase markedly. This is due to the fact that the lens fibres become more closely packed together and lose some of their watery constituents (sclerosis). The older central part of the lens is the first to undergo this process, with the result that a definite hard nucleus is found in the lenses of people about the age of thirty to thirty-five and upwards.
A Lens Three Weeks after needlingFig. 83. A Lens Three Weeks after needling.The section shows the swelling and breaking up of the lens in the anterior chamber. The iris has become adherent to the needle puncture.
Chemically the lens fibres are composed of crystallin, which is closely allied to a serum globulin and is therefore soluble in salt solution. When the lens capsule has been opened, by operation or accident, the saline aqueous is admitted to the lens, which becomes opaque, swells up, and is gradually absorbed (Fig. 83). In those under the age of thirty, therefore, a simple incision into the capsule is all that is required to cause it to be absorbed. But, as has already been pointed out, the lensdevelops a hard nucleus after that age and will not then be absorbed satisfactorily by simply opening its capsule; to remove it, as is done in senile cataract, the hard nucleus must be extracted from the eye.
The lens is held in position by the suspensory ligament, which consists of interlacing fibres attached on the one hand to the ciliary process and on the other to the capsule at the lenticular margins (Fig. 84). Prolapse of the vitreous after cataract extraction is prevented by the integrity of this ligament and the posterior capsule of the lens, together with the hyaloid membrane of the vitreous. The tension on the fibres of thesuspensory ligament, in addition to keeping the lens in its place, also exercises traction on the lens capsule. In dislocated lenses there is a gap in the suspensory ligament either as the result of injury or of congenital malformation; when such cases require operation there is some difficulty in producing a sufficient gap in the capsule to promote their absorption, owing to the mobility of the lens and the want of traction on the incision in the capsule.
Anatomy of the Anterior Segment of the EyeFig. 84. Anatomy of the Anterior Segment of the Eye.Cil. P.Ciliary process.S. Ch.Canal of Schlemm.L. P. Lig. pectinatum, between the fibres of which are the spaces of Fontana.Sup. C. Ly. S.Suprachoroidal lymph-space which extends backwards between the choroidand sclerotic.M. Longitudinal portion}of the ciliary muscle.C. M. Circular portionO. Circulus arteriosus.S. Lig.Suspensory ligament of the lens.E. Epithelium covering the ciliary process.Pars Cil.Pars ciliariis retinæ. Pars plana of the ciliary body.R. The retina.}The junction of these with the pars plana is known as the ora serrata.C. The choroid.J. Iris.S.M. Sphincter muscle.Cry.Crypt.M. M. Pigment epithelium.S. Cornea. Substantia propria.B. M. Bowman’s membrane.D. M. Descemet’s membrane.A. Cap.Anterior capsule of the lens.C. P. Canal of Petit.
Discission of the lens has for its object the tearing open of the anterior capsule, so that the lens substance may be broken up and absorbed.
Indications.This operation will be required:
(i)For cataract in patients under the age of about thirty.The forms of cataract for which these operations are usually performed are: (i)complete congenital cataract, in which the whole lens is opaque and consists of little more than a shrunken capsule which may have to be extracted if discission is unsuccessful; (ii)lamellar cataract, of sufficient density to interfere seriously with vision; (iii)posterior polar cataractin rare instances; (iv)traumatic cataract, to complete the absorption of the lens by breaking up its fibres.
Before operating on any form of cataract the following facts must be ascertained as far as possible:—
(a)Vision.It must be remembered that in children a defective eye retaining the power of accommodation is often more useful than an eye which sees better but has to wear different glasses for different distances. Vision must be reduced to less than 6/18 in both eyes after correction with glasses before the operation should be undertaken. In rare cases, in children, and in traumatic cataract where the cataract is very dense and confined to one eye, it may be removed partly to improve the personal appearance and partly to enable the patient to see large objects.
An eye without a lens (aphakia) will not work with an eye with a lens even if the former be corrected with glasses.
If the patient be unable to see letters, he should have a ready and quick perception of light, no cataract, however dense, being sufficient to prevent this.
(b) A patient should have a goodprojection of light; that is to say, he should be able to locate the light when thrown into the eye with a mirror whatever direction it comes from. Children generally turn the head towards the light, provided that they can see it and that the eye is not defective from other causes.
(c) Note whetherthe pupilsare equal and active. In children most useful information can often be obtained as to the condition of the fundus by means of the pupil, which often will not react when the patient is unable to appreciate light.
(d)The condition of the fundus of the other eye, if observable, should be taken into account, as many diseases of the fundus, such as choroiditis and myopia, are bilateral, and would influence the prognosis considerably.
(e)The lachrymal sacand conjunctiva should be free from all signs of inflammation (seep. 181).
(ii)For the removal of a lens for high myopia.In selected cases operation gives very satisfactory results with great improvement of vision; indeed full normal distance vision has been obtained without glasses. The operation, however, is only justifiable under certain circumstances, the chief of which are:—
In emmetropia, if the lens be removed, a glass of + 11 D. has to be placed before the eye for distance vision and + 14 D. for near vision. It is impossible to predict the exact amount of correction of myopia which will be produced by the removal of the lens, owing to the surgeon’s inability toestimate the refractive power of the lens associated with the distortion of the posterior pole of the globe. Usually a patient with about 22 D. of myopia is rendered emmetropic by the operation.
There are two main objections which have been raised to the operation: first, that there is a slight risk of septic infection, sympathetic ophthalmia even having been known to occur; secondly, that retinal detachment seems rather more common after operation than in ordinary myopia of the same degree. As a rule it is only advisable to perform the operation on one eye, the patient using the other for reading purposes, but under certain circumstances, as when the operation has been successful for a considerable period of time, it would be justifiable to perform it on the other eye. The operation should never be performed on patients having only one eye.
Instruments.Speculum (Fig. 85), fixation forceps (Fig. 86), discission needle.
Eye SpeculumFig. 85. Eye Speculum.
Fixation ForcepsFig. 86. Fixation Forceps.
Operation.First step.The operation is best performed by artificial light. The pupil having been dilated with atropine and the eye anæsthetized with cocaine (a general anæsthetic being necessary, however, for young children), the speculum is inserted by first drawing up the upper lid, making the patient look down, and inserting the top blade, and then drawing down the lower lid, making the patient look up, and inserting the lower blade. The speculum is opened to its full width without undue strain on the canthus and is kept in position by tightening the screw. The eye is steadied by fixation forceps held in the left hand, which grasp the conjunctiva as close to the cornea as possible directly opposite to the spot at which the puncture is to be made; the puncture is made directly behind the limbus and the needle is passed into the anterior chamber.
Second step.Using the shaft of the needle lying in the cornea as a fulcrum on which to rotate the needle, an incision is made in the anterior capsule of the lens, and the lens fibres are broken up by a stirring movement. The needle is then rapidly withdrawn in the same plane in which it was inserted so as to avoid making a crucial incision in the cornea with the spear-like end and thereby losing the aqueous. The best way to make sure of this is to mark one side of the handle so that it may be inserted and withdrawn in the same position. A pad and bandage are then applied.
After-treatment.The pupil should be kept dilated subsequently by the use of atropine twice a day until the lens has become absorbed. The bandage may be removed about the fourth day and dark glasses worn.
The effect of the operation on the lens varies considerably. It mayswell up so rapidly that the tension of the eye becomes increased, in which case an evacuation may have to be performed; in other cases, especially in the cases of a patient with high myopia, several needlings may be required before absorption is complete.
Capsulotomy is the division of the opaque capsular membrane left after a cataract has been removed.
Secondary CataractFig. 87. Secondary Cataract.Opaque capsule after cataract extraction.
Indications.After a cataract has been removed, either by discission or extraction, an opaque membrane is usually left. This is due to the proliferation of the cells in the anterior capsule of the lens while attempting to lay down new lens fibres. Although the posterior capsule is clear and free from cells, those from the anterior capsule may spread to it and so render it opaque. A fibrinous exudate may also organize and help to thicken the membrane (Fig. 87). For these reasons and also because the soft matter may not have absorbed entirely, it is not advisable to operate too soon after a cataract has been removed. There should be at least six weeks’ interval after an extraction has been performed. A few surgeons operate earlier than this, the idea being that the membrane is then softer and more easily divided.
Although the operation of discission for after-cataract (capsulotomy) is simple it is not to be undertaken lightly. The patient’s vision should be less than 6/18. In former days the operation was looked upon as attended with as much risk as the extraction, owing to the frequency with which it was followed by inflammation. The reasons for this seem to have been want of proper antiseptic precautions, the passage of the needle through the non-vascular corneal tissue instead of through the conjunctiva, and also the use of a badly made needle, often resulting in prolapse of the vitreous into the wound. A proper discission needle should have sufficient width in its spear-like point to cut a hole large enough to admit the shaft freely; hence needles which have been sharpened several times should be discarded. It need hardly be saidthat there should be no signs of cyclitis (keratitis punctata) present when the operation is undertaken.
Instruments.These are the same as for discission, with the addition of a needle with a long cutting edge.