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.
[Illustration]
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.
[Illustration]
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.
_Wounds of the Eyeball and its Neighbourhood._—Wounds near the eye,
though unimportant in themselves, require considerable attention,
on account of the eye, or its appendages, being likely to suffer in
consequence. Thus, transverse wounds of the forehead or eyebrow,
if their edges be not approximated accurately and soon, may cause
prolapsus of the eyelids; or the eyelids may become swollen and turgid,
or erysipelatous, in consequence of inflammatory action attacking the
wound. When wounds of the forehead are in a perpendicular direction,
their margins are easily preserved in apposition, having little
tendency to retract, and there is no risk of the relative situation of
the eyelids being altered. If there be considerable loss of substance
in the lower part of the forehead, from the nature of the wound, when
inflicted, or from its having become the seat of unhealthy suppuration,
on cicatrisation of the part the eyelid will be drawn upwards, and
perhaps more or less everted. There is reason to believe that a
degree of blindness, and even complete amaurosis, has been caused by
wound of the eyebrow, the superciliary nerve having been contused,
wounded, or otherwise injured; or the functions of the eyeball may be
disturbed by concussion from injury. Paralysis, also, of the levator
palpebræ superioris, or of several of the muscles belonging to the
eyeball, may follow injury of the forehead and neighbouring parts,
from either laceration or concussion of the nerves. Wounds of the
eyelids, particularly when neglected, may cause much change of relative
situation in the parts, and thereby produce both inconvenience and
deformity. In some instances, the relative position of the puncta
lachrymalia is altered by the cicatrices of the eyelids or tarsal
cartilages, when the original wound has been imperfectly adapted: hence
results an incurable epiphora.