Part 39

_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.

In wounds, such as those above mentioned, it is of great importance to bring the raw edges into contact, and retain them so; and, in most cases, one or more points of interrupted suture are necessary. Adhesive plaster may be at the same time applied, but of itself is insufficient to effect permanent coaptation.

Wounds of the eyeball, however slight, require much attention, being inflicted on an important and highly sensible organ, and there being always a risk of destructive inflammatory action. If the breach of surface be clean, simple, and superficial, rest of the parts will in general be sufficient to effect a cure. Lacerated wounds, and such as penetrate into the interior of the eyeball, cannot be expected to heal without morbid action having been excited: inflammation must be anxiously looked for, and actively combated as soon as it appears. When a foreign body lodges in the wound, it must be early removed. But in certain cases it is imprudent to attempt extraction of foreign matter; as when a small shot, or other minute substance, has lodged in the interior of the eyeball. In such circumstances we can only adopt such measures as prevent and subdue morbid excitement. The organ may remain little disturbed for a short period, but violent inflammatory action soon occurs, and, though subdued for a time, again breaks forth, and, by its successive attacks, may ultimately destroy the eyeball. Frequently all endeavours to avert untoward results are unavailing, and the functions of the organ are more or less impaired—the cornea may become opaque, the iris may protrude, the pupil may become irregular, contracted, or obliterated—the crystalline lens may lose its transparency, amaurosis may occur from injury of the retina, the humours may be evacuated, and the eye sink in its socket. The entrance of a large foreign body into the orbit may displace the globe, and cause it to protrude between the eyelids: in such a case the body should be removed and the ball gently replaced; vision may be soon regained; but, if the protrusion has been such as to cause much stretching of the optic nerve, blindness more or less complete remains. Fatal effects may follow wound of the eye, on account of the foreign body, as a sharp-pointed instrument, penetrating the thin parietes of the orbit, splintering the bone, and injuring the brain.

_Orbital Inflammation._—Inflammation seldom attacks the parts situated between the orbit and the eyeball; but, when it does, the affection is very serious. The action is very acute, and proceeds rapidly to suppuration. The pain is excruciating, extends to the whole head, accompanied with a sensation of extreme tension in the orbit, and is much increased by the slightest motion of the eye: and from the matter accumulating around the ball, and being confined to the unyielding orbit, by the dense fibrous expansion which extends from the margin of the orbit to the interior surface of the eyeball, the globe is pushed forwards, and distends the lids. The palpebræ become erysipelatous, and swollen by serous effusion. Violent inflammatory fever occurs; and, as the disease advances, all the symptoms are aggravated, and become almost intolerable. The globe is farther protruded, and the retina is insensible to light. At length the accumulated matter makes its way to the surface, and is discharged, giving great relief to the patient, and permitting the protruded globe to regain its situation. The inflammation seldom extends to the eyeball.

In the early stage of this affection, the most decidedly antiphlogistic measures are imperiously called for. When fluctuation can be felt, or when the symptoms indicate that suppuration has taken place, whether fluctuation is perceptible or not, an early opening into the affected part should be made through the dense orbital ligament. Thus a free exit is allowed for the matter, the patient is instantaneously relieved, and the extent of the local mischief is limited. It is unsafe to wait for the spontaneous evacuation of the matter: such a process is necessarily tedious, and, before it has been accomplished, the orbital bones may have become diseased; they may have given way at certain points, and the matter may have escaped within the cranium. The artificial opening should always be free, and deep if necessary.

_Tumours in the Orbit._—Sarcomatous tumours occasionally form in the cellular tissue of the orbit. They occur at all periods of life, and may, by slow and gradual increase, cause the eyeball to protrude and disturb its functions; or their growth is rapid, and accompanied with great suffering. In some cases, the eye is made to protrude to a great degree, and by the extension of the optic nerve vision is impaired; in others, the patient is totally blind at the commencement of the disease. Yet the eye may be displaced to no small extent without amaurosis following. The optic nerve appears to bear a good deal of extension without disturbance of its functions. The majority of tumours in this situation are of rapid growth, their structure is soft and medullary, they sooner or later furnish a fungus, and, though removed at an early period, are generally reproduced. The exophthalmos is often the first indication of such a growth, and it is sometimes greater in the early part of the disease than afterwards, when the fascia passing down from the edge of the orbit has given way. The malignant tumours are most frequently met with in childhood, though morbid growths of a bad kind form in the eyeball at different periods of life. They often follow the infliction of a blow or wound. The patient’s sight speedily declines, without any known cause; there is pain in the forehead, temple, and eyeball; the ball protrudes, perhaps slightly, and at first is not otherwise changed; but on careful examination a dimness can be perceived deep in the eye. The opaque body approaches the pupil and fills it, and may in this state be mistaken for disease of the crystalline lens; but the tumour soon pushes forward the iris, and fills the anterior chamber. It has an irregular surface covered with flocculi. Blood-vessels are observed ramifying on it, and by this it is distinguished from cataract, should the accompanying symptoms not have previously convinced the surgeon of the nature of the disease. If not interfered with, the cornea ulcerates, a fungus appears, often grows with great rapidity, and may either furnish not a drop of blood, or bleed profusely. The eyelids are œdematous and permeated by large venous branches. Abscesses form around; the lymphatics of the neck are involved; and the patient succumbs. The original tumour may possess the usual structure of medullary sarcoma, may be of a melanotic nature, or may contain a mixture of both; or it is of harder consistence, containing cells filled with bloody, glairy, or other fluid. The whole coats of the eye are seldom involved: part remains sound, but compressed and disfigured by the morbid mass, and the humours are either absorbed or discharged.

Circumscribed tumours, exterior to the ball, and surrounded by a cellular cyst, may be removed by careful and cautious dissection, without injury to the important parts. A free incision is made along the edge of the orbit, in the course of the fibres of the sphincter oculi. The tumour is exposed, laid hold of with a hook or small vulsellum, and separated from its attachments by a knife, the edge of which is directed towards the new growth. A man, aged 26, had laboured under blindness with exophthalmos for eighteen months. A tumour could be felt above the eyeball, which I dissected out, along with the lachrymal gland, to which it adhered. It was of medullo-sarcomatous structure, and of the size of a plum: at one point it contained a mass of coagulated blood. After its removal, the eye resumed its place and functions. The patient remains well; but such favourable cases are rare.

If the affection be more extensive, it may be necessary to remove all the contents of the orbit: but, in disease involving the entire structures, there is little chance of the patient remaining free from it: it almost uniformly returns, as is also the case whenever the disease has commenced in parts of the eyeball. The optic nerve is often affected at an early period: its cut surface is unsound; and from this, again, springs a fungus which grows rapidly. But under many circumstances the surgeon is not only justified in removing the orbital contents, but called upon to do so. The operation, though cruel and painful, need not be tedious. The commissure of the eyelids is divided with the point of a bistoury, and the forepart of the ball laid hold of firmly and deeply with a vulsellum—that is, forceps provided with a double hook at each extremity of the blades. A straight bistoury is then entered at the margin of the orbit, pushed down to the base, as near as possible to the entrance of the optic nerve, and carried round the tumour rapidly, the blade towards the handle being made to move more quickly than the point. The nerve is cut across, and, after the removal of the morbid mass, the cavity is sponged out and examined. The lachrymal gland, and other soft parts, particularly if altered in texture, are raised with a hook, and removed by means of curved scissors. In young subjects, and in adults, when the disease is far advanced, the parietes of the orbit are thin, softened, and attenuated by pressure: the knife should therefore be used cautiously, and it is, perhaps, safer to finish excision with a narrow, curved, and probe-pointed bistoury, after having penetrated to the bottom of the orbit with a sharp-pointed knife: all other curious and crooked knives are useless. Bleeding is restrained by charpie, pressed firmly and quickly into the cavity, and supported by compresses and bandage; but, before introducing the dossils, all coagula and fluid blood should be carefully sponged out. Afterwards, excited vascular action, with pain in the head and wound, may in some subjects require abstraction of blood, the exhibition of purgatives and antimonials, and immediate removal of the dressings, followed by fomentation and poultice. When matters proceed favourably, the charpie is removed gradually as suppuration advances, and the granulations are supported with light dressing, either dry, or moistened with some slightly astringent lotion. The discharge will gradually cease, and the granulated surface cicatrise under the level of the eyelids. In such circumstances the deformity may be remedied, after the parts have become quiet, by the adaptation of an artificial eye of enamel, made so as to resemble exactly the other eye. It is worn without inconvenience, removed at night like artificial teeth or a wig, and cleaned and replaced in the morning. Such a substitute is also useful when the humours have been evacuated, or the organ destroyed, by injury or the effects of inflammation. Too frequently the morbid growth is reproduced, and that rapidly. It may be restrained by escharotics, the red oxide of mercury, potass, acetate of lead, acids, or the actual cautery; but the patient is thereby put to much pain without a chance of ultimate benefit.

It is too true, that the hopes of a cure, after the extirpation of the eyeball for malignant disease, are defeated by the prior existence of a similar affection within the cranium. In the majority of cases, death has occurred from tumours of greater or less extent, along the course of the optic nerve, or their tract: behind the commissure, and extending to the optic lobes and even cerebellum.

[STRABISMUS.

Strabismus, or squint, as it is vulgarly designated, may be defined to be an aberration from the natural direction of the optic axes, by which the consent between the eyes is destroyed, and vision more or less impaired. The resulting deformity varies in different cases, from the slightest possible cast to the most disagreeable obliquity. The affected organ may be turned inwards or outwards, upwards or downwards, according to the muscle upon the derangement of which the squint depends. When the eye is directed inwards, it constitutes what is called convergent strabismus; if, on the other hand, it inclines outwards it is said to be divergent. The upward and downward obliquities have not received any particular names. As might be supposed, these different forms of strabismus do not occur with equal frequency. On the contrary, two of them are so rare that I have not yet met with an instance, though I have examined the eyes of a very considerable number of persons labouring under this infirmity. These two forms are the upward and downward, both of which, but especially the latter, are so seldom witnessed that their occurrence may well be doubted, except as the result of external violence.

The most common variety of strabismus by far is the convergent, in which the eye is directed inwards, or inwards and upwards. Of 536 cases collected from various sources by a writer in the Philadelphia Medical Examiner, 506 were of this description, a proportion which fully accords with my own but more limited observation. The degree of obliquity may be very moderate, or so great that when the person looks directly forwards with the sound eye the cornea of the other shall be almost entirely concealed at the inner canthus. It is worthy of remark, that in this form of the lesion, at least so far as my own experience goes, the organ rarely, if ever, inclines downwards, but nearly constantly somewhat in the opposite direction.

Next in point of frequency is the divergent form, which, however, is comparatively rare. Of 866 cases reported in the work above alluded to, it was noticed only forty-four times; and thus far I have myself seen only three or four examples of it. The eye in this variety of strabismus is seldom drawn out very far, nor is it so apt to be attended with the same amount of upward obliquity as the convergent.

It seems to be the general sentiment of writers on strabismus, that, in the great majority of cases, only one organ is affected. Thus, in the article in the Philadelphia Examiner, before adverted to, it is stated that the distortion occurred 459 times in one eye, and only 47 times in both. Dr. Dix, of Boston, in a small treatise on strabismus, makes a similar remark. Of 50 cases which fell under his notice, the lesion is said to have been limited to one eye in 36. Now I am convinced from a good deal of experience that nothing can be more unfounded than this opinion, which is to be deprecated the more because it is calculated to lead to very serious errors in practice. I unhesitatingly assert, that in nearly all instances, at least of convergent squint, both organs are implicated, though not in an equal degree. Usually—perhaps always—one is more affected than the other, which the patient, therefore, regards as his good eye, as it is the one which he constantly employs in viewing objects. Nor is it surprising that this should be the case, when we recollect the remarkable sympathy existing between these structures, and the fact that when one eye is diseased the other is very liable to take on morbid action also. Amaurosis of one eye is very often followed by a similar malady of the other, and the same is true of cataract and some other affections. In the natural state there is a perfect agreement between the optic axes, produced by the harmonious action of the straight muscles, but when this consent is destroyed, as it is in strabismus, the eyes lose their parallelism, and the distortion in question is the consequence.

As was previously intimated, one eye is commonly more affected than the other, and this, if I mistake not, will be found to be the left, though it is impossible, in the existing state of the science, to indicate the proportion. Mr. Lucas thinks that the proportion in favour of the left eye is as three to two; Dr. Phillips of Liège, on the other hand, maintains that the right organ is more frequently involved than the other. It rarely happens that both eyes become deranged simultaneously; on the contrary, one generally squints first, and after a while the lesion begins in the other, the interval being probably very short.

Whether strabismus occurs with equal frequency in both sexes, is still an unsettled question. Of thirty-two cases on which I have operated, only five were females, whereas in the fifty cases published by Dr. Dix, of Boston, only nineteen were males, thus exhibiting a most remarkable disparity in reference to this point. The difference, if any, is perhaps not great either way, and, as it is of no practical importance, it need not be pursued any farther here.

The exciting causes of this affection are numerous and diversified. One of the most frequent is imitation. Nearly one-seventh of all the cases that occur are probably induced in this manner. Hence our schoolrooms may be regarded as a fruitful source of mischief, one cross-eyed child being often the cause of strabismus in many others, merely from that habit of imitation to which the young are so much addicted. Ophthalmia, by whatever cause induced, is another, and that a very common source of this distortion. I have seen repeated instances of this kind, and many others are mentioned by authors. Convulsions, eruptive diseases, such as measles and scarlet fever, hooping-cough, derangement of the digestive organs, injury on the eye, and difficult dentition, may all be enumerated as so many causes of the lesion in question. Frequently it arises without any assignable reason, and when the individual is in the most perfect health. Occasionally it is congenital, or, what is more probable, makes its appearance within a few days after birth.

It is supposed that strabismus is occasionally hereditary. This is doubtful; for if we sometimes meet with cross-eyed children whose parents, one or both, are similarly affected, it by no means proves that the distortion was transmitted to them in the manner of certain maladies. It only shows a coincidence, which may be explained, in most instances, on the assumption that the children have acquired the obliquity by imitation, or by some other cause, not that it was entailed upon them previously to birth. In the same manner we may satisfactorily account for the existence of strabismus in several members of the same family, of which a remarkable instance has recently come under my own observation. Of three brothers, one has three children affected with it, another two, and a third one. The parents have all sound eyes, and so have the uncles and aunts, except one, on whom I operated successfully several months ago. Last autumn I operated for cataract on three children belonging to a gentleman from Mississippi, who informed me he had six others at home, of whom three were affected with strabismus. Both parents, as well as their immediate relatives, are free from the affection.

Strabismus essentially consists in a contracted state of one or more of the muscles of the eye. This, as was before intimated, is commonly the internal rectus. The shortening, varying according to the extent of the squint, is always attended with a corresponding elongation of the opposite muscle, so that it gradually loses, either in whole or in part, its antagonising influence. How this affection is brought about, in the first instance, is still unknown, though it is probable that it depends upon some lesion of the nerves which supply the muscles of the eye, rather than upon any actual lesion of these fleshy bundles themselves. Be this as it may, when the resultant distortion is permanent, the affected muscle, from being constantly engaged in holding the eye in its unnatural position, acquires a corresponding degree of development, in accordance with a law of the animal economy that, in proportion as an organ is exercised, will be its size and strength. The more frequent occurrence of convergent strabismus is owing, doubtless, to the fact that the internal straight muscle is not only larger and stronger than the others, but that it is inserted much nearer the cornea, deriving thus two important mechanical advantages.

One of the most disagreeable effects of strabismus is the deformity to which it leads, rendering the individual an object of constant observation and ridicule. Were this confined to infancy and childhood, it would be of comparatively little consequence, but when we reflect that it continues through life, and that it is a source of incessant mortification, the influence which it exerts upon the temper and disposition of the sufferer must often be of the most unhappy kind. A still more serious effect, however, is the impairment of the vision of the affected eye, which, never entirely absent, sometimes amounts nearly to a total loss, from the insensibility of the retina, which is sometimes as complete as in confirmed amaurosis. In another series of cases the person is myopic, or sees objects only at a short distance. In some instances, again, there is double vision, or objects appear indistinct, and run as it were into each other, the image painted on the retina being confused and imperfect.