Elements of Surgery

by Robert Liston

DISEASES OF THE EYE AND ITS APPENDAGES.

Of Inflammation and Abscess of the Lachrymal Passages.—In former times, all affections of the lachrymal passages, and of the parts in the neighbourhood, were denominated fistula lachrymalis, and were all treated nearly in the same manner, by opening the sac, and inserting probes, knives, terebræ, scalpra, caustics, and red-hot irons; the anatomy of the various parts being then ill understood, and the opinions as to the origin and nature of the diseases being founded on erroneous theories regarding the defluxion of acrid humours, formation of imposthumes, fungous growths, &c. The term, however, which was indiscriminately applied to all diseases in the inner corner of the eye, accompanied with derangement of the lachrymal secretion, is now confined to a distinct form of disease, as will afterwards be mentioned.

Inflammation sometimes occurs in the loose cellular tissue covering the lachrymal sac,—whilst that cavity remains free of all disease,—and is attended with some obstructions to the passage of the tears in their natural course, on account of the eyelids becoming swollen, from an extension of the inflammation. The morbid action resembles erysipelas in its nature, and usually terminates in unhealthy suppurations; thin purulent matter lodges in the opened out cellular membrane, a soft boggy tumour is formed, and the superimposed integuments become of a bluish colour, as in the case of other scrofulous collections.

Though the affection is at first unconnected with the lachrymal sac, this organ may ultimately be involved. It may become the seat of a like unhealthy inflammation, and matter may consequently form within its cavity; or, on account of the pressure of interstitial deposit around, the parietes of the sac may ulcerate before the abscess of the cellular tissue in front has discharged externally. Thus, the cavities of the lachrymal sac, and of the external abscess, will communicate with each other. If, after an external aperture has been made either by nature or by art, any doubt exist as to whether the sac is involved or not, such doubt will soon be removed by dexterous use of the probe.

In the treatment of this affection, it will be necessary, at the commencement, as in all other local inflammatory diseases, to attempt the accomplishment of resolution, by attention to the general health, local abstraction of blood, and warm fomentations. When matter has formed, it ought to be evacuated as soon as possible by a small incision, as there will then be less risk of the deeper parts becoming secondarily affected; or if the integuments have sloughed, and the matter has been discharged spontaneously, the natural opening may be enlarged either with the knife, or with the caustic potass. If it be discovered that the lachrymal sac is opened into, the same treatment is necessary as if it remained entire; the matter is to be allowed free exit, and granulation encouraged; in most cases, the aperture in the sac is soon repaired, and the parts heal as quickly and soundly as if the disease had been confined to the external cellular tissue. Light dressing during the cure, preferable in all cases, is more especially necessary in this situation.

Of Inflammation of the Lachrymal Sac.—When the lachrymal sac becomes inflamed, it enlarges considerably; the swelling is small, hard, circumscribed, deeply seated, and extremely painful, more especially on pressure. At first the integuments are of their natural appearance, the increased action being confined to the sac, but they are soon involved, and often to a considerable extent; they become red and swollen, and as the surrounding parts are affected, the swelling increases. In some cases, the eyelids, the caruncle, and the conjunctival covering of the eye, participate in the inflammatory action. The inflammation is in most instances caused, or at least preceded, by some obstruction in the nasal duct, in consequence of which, the tears are interrupted in their natural course downwards, and either accumulate in, and distend the sac, or flow over on the cheek, the puncta lachrymalia remaining open. After increased vascular action has been produced, the lachrymal secretion is increased to a greater or less degree, and much inconvenience is caused to the patient by the profuse discharge following an unnatural course. When inflammation is intense, lymph is effused into the passages, producing obstruction sometimes complete. The mucous lining of the nasal duct becomes swollen, from the vascular excitement, either throughout its whole extent, or at one point only; and in either case the flow of the tears must be interrupted, either partially or wholly, according to the degree of swelling. The vitiated secretion of the part may also contribute towards narrowing the canal, by lodging and concreting there. But a more complete and permanent obstruction is formed by effusion of lymph, under or on the mucous lining, as happens in other canals of similar construction: and in this case also, the stricture may be partial or complete, according to the quantity of effused matter, and the extent of surface affected.

As the inflammation abates, mucous fluid is copiously effused from the surface of the sac, and the swelling increases, though the pain is less. The collected fluid may be partially evacuated through the puncta, either spontaneously, or in consequence of the patient instinctively pressing with his finger on the swollen part; or the puncta may be obstructed by the same causes as the nasal duct, and then the discharge of the fluid is prevented in both directions; it consequently accumulates still more, and causes greater bulging. Fluctuation is perceptible, and the collection protrudes outwards and forwards, being least resisted in these directions. It is seldom that the puncta are obstructed, and consequently the swelling does not attain any great size, the sac being relieved by some of its contents always flowing upwards, after a certain degree of distension. As the inflammation farther subsides, the mucous secretion diminishes, and the accumulation and swelling are less: in fact, the patient may at this period prevent a tumour from forming in the corner of his eye, by from time to time pressing gently on the sac, and forcing the lachrymal secretion upwards, as it begins to accumulate. This state of matters may continue for a long period, without causing much inconvenience, and getting neither better nor worse; the patient is merely obliged to apply his finger and handkerchief more frequently to his eye than would otherwise be required. In almost all cases, the obstruction of the nasal duct is complete, or nearly so, and consequently the fluid cannot pass downwards into the nose, though it may occasionally appear to do so, on account of the discharge from the Schneiderian membrane being increased at the same time with that of the lachrymal sac. The ductus ad narem, though wide in the skeleton, is of very limited dimensions in the living body, and is in consequence readily made impermeable to mucous fluid, by even slight thickening of its lining membrane.

It has been already observed that the above-mentioned condition of the parts may continue for a considerable period; but in other cases purulent matter soon forms within the distended sac; or, at least, the contents of that organ are so altered in colour and consistence as to resemble intimately purulent fluid. The secretion may or may not be pus, probably it is not in some cases; but as the decision of this point is practically unimportant, the description of it as purulent can scarcely be objected to. In most cases, when the puncta either are or become clear, no suppuration, or deterioration of mucus into fluid like pus, occurs; merely chronic distension of the sac continues, the patient being able to avert incited action, by occasionally squeezing out the contents, and thereby removing tension. There is merely an Epiphora; or, as it is otherwise called, Blenorrhœa, or Stillicidium lachrymarum. The last term is by some applied to increased lachrymal secretion, without affection of the sac, the tears being secreted more quickly than the puncta can carry them away, and consequently running over on the cheeks, excoriating the surface, and producing an irritable condition of the eye. The simple epiphora may be of long duration, yet the parts are extremely liable to assume inordinate action, in consequence of slight injury, or exposure to cold; thus suppuration will ensue.

When purulent matter forms, fluctuation becomes more distinct, the pain increases, and there is slight headache and fever. The integuments inflame more and more, and, if the case is neglected, ultimately give way by sloughing. A small ragged opening, often indirect, is formed, and the contents of the sac are not thereby all discharged; the thinner fluid only escaping, whilst the more viscid remains and clogs the aperture. The swelling is not much diminished; the margins of the aperture thicken, become indurated, and contract, the purulent contents of the sac are gradually discharged, and the tears afterwards flow through the opening. The parts are now in that condition to which the term Fistula lachrymalis is with propriety applied. The

swelling of the canal may gradually subside, the tears resume their wonted course, and the opening may then contract, and the parts cicatrise; but frequently the fistula remains open for a long period, gradually diminishing in diameter, and only a small passage, almost imperceptible, ultimately remaining, through which a few drops of lachrymal fluid are occasionally discharged. Sometimes the fistula closes entirely without the obstruction of the nasal duct having been removed, and the lachrymal sac remains in consequence distended; then the tears or mucus, either clear or turbid, can generally be squeezed through the puncta.

It frequently happens that the meibomian glands are the seat of morbid action, along with the lachrymal passages; their secretion is changed, becoming in some cases thick and caseous, in others puriform. By some, affection of the meibomian glands has been considered as the cause of inflammation and abscess of the lachrymal sac. This opinion, however, cannot be agreed to, for the diseases are not always coexistent; and besides, the affection of the surface of the lachrymal sac and ductus ad narem is as likely to be the consequence of morbid action, extending upwards from the nostrils, as of morbid secretion from the eyelids blocking up and irritating the puncta and the lachrymal passages. Disease of the meibomian glands in the under eyelid often exists along with disease of the lachrymal passages, but the latter is generally the primary affection; the conjunctival covering of the eyelid is at the same time inflamed, swollen, and often granulated.

In some cases of abscess in the lachrymal sac, before the integuments give way, the subjacent bone becomes diseased in consequence of the pressure of the confined matter; portions are affected by necrosis, and after their separation considerable deformity is produced. The exfoliation is often very tedious, and is attended with discharge of fetid thin fluid from the nostril, and from the ill-conditioned lachrymal fistula.

Fistula lachrymalis is often merely one of the symptoms of disease in the bones of the nose, with obstruction of the nasal duct,—as in patients who have suffered from mercury.

Treatment.—In the treatment of epiphora or blenorrhœa—that is, chronic collection of a mucous fluid in the lachrymal sac, with weeping of the eye—a primary object of attention is the state of the general health. The habit of the patient will commonly be found weak, and, if not decidedly strumous, at least inclining towards that diathesis. In such cases the digestive organs must, if possible, be brought into a vigorous state by tonics and nourishing regimen. The local treatment chiefly consists in applying stimulants to the internal surfaces of the palpebræ and lachrymal sac. For this purpose, solutions of stimulating and astringent substances, termed collyria, and various ointments, are employed. At first they ought to be used of rather a mild nature, and their stimulating power must be afterwards increased gradually. The applications are placed between the eyelids, and, becoming mixed with the natural secretion, pervade the diseased surfaces; and, being taken up by the puncta lachrymalia, are afterwards conveyed into the sac. It was formerly the custom to inject the fluids into the sac; but this is unnecessary so long as the puncta and canaliculi remain pervious, and the permeability of these can be readily ascertained by means of a small probe. Permanent pressure on the sac can be productive of no good effect, and is extremely liable to do harm. The repeated application of very small blisters over the sac has been found useful.

Introducing minute gold probes through the puncta has been much recommended, but in the generality of cases can be of little service. The probes are too limber for removing mechanical obstruction, or for affecting in any way the contracted or strictured duct. But passing of the probe may tend to remove the irritability of the passage, as happens in the urethra, and thence some relief may follow. Much dexterity is required in using either the probe or syringe. The puncta are often very small, and it is in general necessary to dilate them by means of the point of a common pin, before any instrument can be passed through them into the sac. The point of the probe being introduced into the punctum, either superior or inferior, must first be carried towards the nose for about 2-10ths of an inch, the instrument being lightly held betwixt the fore and middle fingers of the right hand. It is then directed downwards and backwards. Care must be taken to prevent entanglement in folds of the membrane. Should obstruction be felt, the instrument is withdrawn a little, and then carefully and gently carried in the right direction. The small syringe is managed with one hand, whilst, with the forefinger of the other, the punctum not occupied by the pipe is compressed.

Neither can much or any benefit be expected to follow attempts to force obstruction in the lachrymal passages, by the weight of a column of mercury. A plan of dilating and rectifying the nasal duct by styles introduced through the puncta has been proposed, but scarcely deserves to be mentioned as a means of cure.

When suppuration is threatened, with increase of the swelling, inability of the patient to empty the sac by pressure, redness of the integuments, &c., an early opening should be made into the tumour, in order to prevent further and more serious mischief. A small opening into the sac cannot be productive of so much injury as forcible dilatation of the canaliculi, followed by and causing ulceration. The point of a straight narrow bistoury is to be entered into the sac, and carried on into the nasal duct, the knife being pushed downwards, backwards, and a little inwards, in the direction of that passage. The point to be punctured can always be readily ascertained by feeling for the firm ligament which attaches the orbicularis palpebrarum to the nasal process of the superior maxillary bone, as the upper orifice of the ductus ad narem is situated immediately below this tendon; by introducing the knife below the ligament, and within the sharp edge of the orbit, and then carrying it forward in the direction already mentioned, the surgeon cannot fail to enter the nasal duct. The knife should be followed by a probe, and ought not to be entirely withdrawn till the probe is fairly lodged in the duct, otherwise the surgeon will experience much difficulty in the after proceedings. If the knife be not pushed into the duct, a blunt instrument can scarcely be introduced afterwards. Some force is required, but is not hurtful, provided it be made in the proper direction, so as to remove the obstruction in the duct without injuring the bones and other parts in the neighbourhood. After the operation, some drops of blood should escape from the corresponding nostril, showing that it has fairly entered this passage; or the patient being made to expire forcibly, the nostrils being at the same time compressed with the fingers, air, blood, and mucus are forced upwards through the opening made.

Many and various modes have been pursued with a view of securing a pervious state of the nasal duct. Instruments of different kinds have been introduced through the puncta, through the opening in the sac, and through the termination of the duct under the spongy bone, and have been retained for a longer or shorter period, according to the fancy, or theory, or plan of the surgeon. The first of the methods of introduction is abandoned, as already stated. By the ancients the passages in fault were got rid of altogether, being either cauterised or destroyed by escharotics.

The passing of probes into the duct from its lower aperture is useful in removing trifling obstructions caused by concretion of deteriorated mucus, or slight thickening of the lining membrane, and in chronic dilatation of the sac with probable contraction of the duct. But, at the same time, it is an operation requiring much dexterity, and which ought not to be attempted till after much practice on the dead body. The first introduction of the instrument is always the most difficult, from obstruction by a valvular projection of the membrane at the lower orifice, the use of which in the healthy state of the parts must be apparent. Destruction of it renders after-introduction of instruments much more easy.

But the preferable practice is making an opening into the sac, and then introducing instruments from the upper orifice of the duct; more especially in cases where the swelling and pain are considerable. The instruments employed for dilatation of the passage are tubes and styles. The tubes are made either of silver or gold, of equal calibre throughout, and of the same length as the passage. For some time after their introduction they cause much irritation; this gradually diminishes, and the wound heals over them. But, according to my experience, the effects are not satisfactory. The irritation which they at first occasion generally subsides, but abscess again occurs, with much swelling, and it becomes necessary to remove the foreign body. Again, the tube sometimes becomes obstructed by thickening and concretion of the discharge, and then, when it is necessary to remove it, the process is found to be by no means an easy one; a free incision is required; a screw must be fastened into the tube, or, when that cannot be accomplished, the foreign body must be laid firmly hold of with strong forceps; altogether the extraction is very painful, and often extremely tedious. In short, the practice of introducing tubes does not appear to be founded on sound surgical principles.

After extensive and impartial trial of both the tubes and style, I decidedly prefer the use of the latter. On the point of the bistoury being fairly lodged in the lachrymal duct, a probe is passed along it; the knife is then withdrawn, and the passage is gently dilated by the probe. The probe again is followed by the style, which should be made of silver, of the same thickness throughout, of the same length as the duct, and with a flattened head placed obliquely to the body of the style. The size of the style should be at first small, and gradually increased. The irritation caused by the first introduction is in many cases very severe, but the parts soon accommodate themselves to the presence of the foreign body; the pain and swelling diminish, as also the discharge. If a large style be pushed forcibly in at first, violent inflammatory action will ensue, and much mischief may be produced. After irritation has gone off, the tears pass readily down in the nose by the sides of the style, according to the laws of capillary attraction, little or no fluid escapes from the external opening, the wound contracts around the instrument, and, its head being covered with black wax, no deformity is produced. The instrument should be removed from time to time, cleaned, and replaced. When, by the continued use of styles gradually increased in size, the duct has been dilated to its full extent, and appears restored to a sound condition, the instrument may be withdrawn, and afterwards introduced only occasionally. The external aperture, which has become fistulous from the long presence of the foreign body, then begins to contract, and, on its completely closing, the tears continue to follow their usual course, and the disease is overcome. But sometimes a small fistulous aperture remains, and there appears to be a disposition towards the renewal of the affection; in such a case, a small style, not exceeding a thin gold probe in diameter, should be introduced every evening, and retained for some hours: this causes little or no inconvenience to the patient, and insures the permeability of the canal.

Such is the method by which a permanent cure may often be obtained, and which, in my opinion, is preferable to the use of tubes. If these are to be employed, they should, as already mentioned, be nearly of equal calibre throughout; the external opening must not be allowed to close for a considerable time after the introduction of the instrument; and the tube must be kept pervious for some time by a style introduced through it. But by these means, which are essential for the success of the practice, the main advantage arising from the use of a tube, viz., little irritation being produced at first, and the parts being allowed to close soon over it, are completely done away with.

The practice of perforating the os unguis never can be required; it is cruel, unnecessary, and unsurgical.

Sometimes the lachrymal passages are entirely destroyed. In such cases, it has been found that no great inconvenience arises from their obliteration, as the lachrymal gland ceases, in a great measure, to secrete fluid, and the conjunctival secretion, after having performed its office, evaporates from the surface. In truth, the lachrymal gland always enjoys long periods of repose, and is only called into active exercise of its functions occasionally, as the eye in its ordinary condition is sufficiently lubricated by secretion from its conjunctival covering.

The treatment of fistula lachrymalis, as has been well remarked by an eminent author, must be varied and regulated according to circumstances;—by the degree of obstruction in the duct, by the state of the coverings of the sac, of the sac itself, and of the subjacent bone, and by the general state and habit of the patient.

Encanthis is a tumour situated in the corner of the eye. The caruncula lachrymalis appears to be the original seat of the disease, at least it is involved at an early period. The growth is at first

small, and appears to be simple enlargement of the caruncle: it is of a reddish colour, and its surface is studded with numerous granulations. It often attains a very considerable size; and, on account of its propinquity to the lachrymal passages, is accompanied with watering of the eye, the puncta being either involved in the growth, or compressed or displaced by it. Sometimes the whole inner corner of the eye, from the margin of the cornea to the inner junction of the eyelids, is occupied by the granulated swelling; and in such cases it is not uncommon for the tumour to extend itself outwards, in the form of a lunated appendage, on the under surface of each lid; thereby the motions and functions of the ball are much impeded, and a prominent deformity is occasioned. In most instances the growth seems to be a simple enlargement of structure, and is of a benign nature; but sometimes it is firm, hard, of rather a livid hue, with a smooth slimy surface, and is decidedly malignant,—enlarging, and gradually involving the surrounding parts.

Cancerous ulceration, attacking and destroying the eyelids, and the parts around the ball of the eye, often commences in the situation of the caruncle, or in a wart on the edge of the lid. Cancer, though a rare and uncommon disease of the eyeball, frequently seizes on the appendages of the eye, extending rapidly in all directions, and often completely detaching the ball by ulceration. Warty tumours also occur on the conjunctiva of the lids, or of the ball, and are inconvenient as a source of much irritation to the neighbouring parts, even though of a benign nature in themselves.

Extirpation, by means of a small pointed knife, or curved scissors, is the only means to be relied on for the cure of such warty tumours, and of encanthis. The growth must be fixed and pulled outwards with a small hook, and carefully dissected away; the eyelids, and, if necessary, the ball of the eye, being kept fixed with the fingers, or by means of a speculum: the fingers are generally sufficient, and more convenient than any instrument. If from the appearance of the parts, and from induration surrounding the tumour, malignant action has evidently taken place or is dreaded, then the incisions must be made wide of the base of the swelling. For malignant, open, and extensive ulcerations, nothing can be done farther than to allay the pain, and soothe the constitutional disturbance. On the whole, encanthis is a rare disease; however, I have seen, and operated on, several instances of it.

Encysted Tumours of the Eyelids.—These occur beneath the conjunctival lining of either the upper or under lid, but most frequently in the former. They form rapidly, but seldom attain any very considerable size; and may be found to contain, along with glairy fluid, a mixture of pus, or curdy matter. The contents, however, are generally glairy, rarely atheromatous. The cysts are very thin and adherent, and the tumour projects externally, forming a dusky red elevation of the integuments. They cause considerable deformity, watering of the eye, and stiffness and difficulty in moving the lids. On everting

the eyelid, the contents of the tumour are seen shining through the distended conjunctiva, and present a bluish appearance. They are seldom single, and are not remediable but by operation. It is improper to attempt their extirpation from without, as there is a certainty of cutting completely through the eyelid, the inner covering of the cyst being merely attenuated conjunctiva. The lid is to be everted, and an incision made into the prominent and thin cyst with the point of a cataract knife; the contents can then be readily scooped out with the end of a probe. It is impossible to dissect out the tender cyst entire, and, when this is attempted, the cure can seldom be permanent. If, after incision and discharge of the contents, nothing farther is done, the disease will almost certainly return, in consequence of the remaining cyst reassuming a secreting action. The only effectual and radical cure is the application of a finely-pointed piece of caustic potass to the interior of the cyst, after discharge of the contents and cessation of bleeding. The cyst is thereby completely destroyed. A slip of soft lint, dipped in oil, is interposed betwixt the lid and eyeball, for an hour or two, in order to protect that delicate organ from the caustic. The wound suppurates and heals kindly, and no mark is visible, the incision having been made from within. I have had no instance of return of the disease since adopting this practice; and I have operated on many which had been previously treated by other and ineffectual means. The laceration of the cyst with a pointed probe is sometimes followed by a permanent cure, but it cannot be depended upon.

Closure of the Eyelids may be either congenital, or a consequence of injuries, as burns of the parts. The closure may be complete or partial. In general it is partial, though perhaps extensive; and the adhesions can be readily separated by the point of a knife, or small probe having been previously introduced beneath; or a small and narrow probe-pointed bistoury may be conveniently used for the purpose. In the after-treatment means must, of course, be taken to prevent the lids from again adhering.

Ectropion, or eversion of the eyelids, may be produced, merely by swelling of the conjunctival lining protruding the lid: or the lid may be relaxed, and the conjunctiva may swell in consequence of repeated inflammation of the parts, caused by frequent and careless exposure; or the disease may be the result of contraction, by cicatrisation of the integuments of the face, as after burns, extensive superficial wounds in the neighbourhood of the eye, or the effect of periosteal disease of the orbit. The affection may exist to a greater or less degree, being in some instances scarcely visible, and not troublesome, whilst in others, the eyelashes lie on the upper part of the cheek,

and the swollen granulated conjunctiva is exposed. The lower lid is generally the one which is affected. The disease may exist in both eyes, or only in one. In strumous habits both are frequently affected in a slight degree; and the upper lid, too, is sometimes turned a little outwards. When eversion is of long continuance, and complete or almost so, the conjunctival covering of the ball of the eye, and of the cornea, becomes dry and wrinkled; in short, the membrane completely changes its character, and becomes cuticular. In a lad who laboured

eleven years under eversion of the upper and lower lids—arising from abscess and exfoliation of the external angular process of the os frontis, following a blow received when a boy—the conjunctiva was hard, wrinkled, scaly, and exactly similar to cuticle: this change of the membrane also extended over the whole cornea. The surface of the eye had lost its lustre, and vision was much impaired, the patient being able to distinguish only very bright objects. By such cases, continuity of the conjunctiva with the outer layer of the cornea is beautifully demonstrated.

Some of the most intractable of all cases of eversion are the result of burns. The constantly increasing contraction of the cicatrix draws either the upper or the lower lid far from its natural situation, and produces frightful deformity. The tarsal cartilages are greatly extended, and in any operation for the relief of the patient it is necessary to remove a portion before the lid can be properly adapted.

Great inconvenience is caused by the state of eversion: the surface of the eyeball is subject to inflammation, in consequence of being insufficiently protected; the change of its investing membrane is a serious evil; and in some cases the cornea becomes extensively ulcerated, unusually vascular, and opaque.

When the conjunctiva only is in fault, the deformity is slight, and the state of matters is readily ameliorated by excision of the relaxed portion. This is done by sharp curved scissors. As the wound gradually contracts, the eyelid is drawn inwards, and, on cicatrisation taking place, the parts have become restored to their healthy condition. Care, however, should be taken that too much of the swollen conjunctiva is not removed, otherwise the subsequent contraction may cause inversion of the lid. Combined with the above practice, relaxation of the lid itself will in many cases be remedied by removal of a portion of it in the form of the letter V, by means of a sharp-pointed bistoury: the edges of the incisions are afterwards put together by a point of interrupted suture. When eversion arises from a cicatrix of the integuments, the part in fault may be divided; but a temporary benefit only can be procured. For, during the healing of the wound, the parts again contract; and, though a portion of the conjunctiva is at the same time removed, the contraction internally will hardly counteract that which is going on externally. In order fully to obviate the evil of this contraction of the cicatrix in inveterate cases of ectropion, a form of plastic operation may be successfully resorted to. The cicatrix being dissected out, and the tarsal cartilage brought neatly into position, a piece of integument from the temple or cheek may be adapted, and a portion of a new eyelid formed. The parts may sometimes be brought into a good position without the necessity of borrowing any portion of integument. A V-shaped incision can be made, the apex pointing downwards, so as to loosen the under lid; and after it has been drawn upwards and put straight, the edges of the lower part of the exposed space are united by suture.

Entropion, or inversion, consists in the turning in of the tarsal margins of the lids, and generally takes place during inflammation and swelling of the conjunctival lining of the lid. During violent inflammation of the lid the conjunctiva and integuments are much swollen, and bulge out externally; by the projection the margin is forced mechanically towards the ball, and entropion takes place. But

in this state of matters, should the lid be by any chance everted, and not replaced, then the bulging is from the conjunctival surface, and prevents the margin from regaining its former site, and permanent eversion or ectropion occurs. In fact, inversion and eversion, like phymosis and paraphymosis, exist from the same parts being put in different relation to each other. More permanent entropion is caused by the contraction which follows removal of tumours from the under surface of the lids, or destruction of large portions of the conjunctiva. The disease is most frequently met with in the upper lid.

Trichiasis consists in a vicious bend of the eyelashes, or in a supernumerary growth in the rows or numbers of individual cilia, whereby they are inverted, and sweep the surface of the conjunctiva covering the cornea; thus great distress is caused by the friction of the hairs and edge of the lid on the sensible surface of the eyeball, and inflammation is frequently kindled and kept up by the continued irritation; it is accompanied by its usual distressing symptoms when seated in that organ, and too often followed by a greater or less number of untoward consequences. Sometimes only one or two hairs are at fault; in other instances, the half of the eyelash grows inwards; and sometimes there is a double row of cilia; one set being in the usual position, while the other projects against the eyeball. If proper means are not taken to remedy the evil, and moderate the irritation which it produces, the cornea becomes thickened and changed in structure; and vision, at first impaired and indistinct, may be entirely lost.

The symptoms may be for a time palliated by plucking out the faulty hairs, abstracting blood from the loaded vessels, and subsequently using ointments or collyria,—the best of which, perhaps, is the solution of nitrate of silver. In some cases it may be necessary to employ counter-irritation, as blistering the nape of the neck; and in all the general health must be strictly attended to. Other means may be required, and will be mentioned when treating of chronic ophthalmia.

The permanent cure of the disease is effected either by removal or by destruction of the roots of the cilia. The whole edge of the eyelid, or the offending part of it, is removed with a sharp narrow bistoury, the operator steadying the parts by laying hold of the cilia with the fingers of his left hand. It is necessary to remove the mere edge only, the cilia and their roots, and not the whole of the tarsal cartilage, as has been proposed.

Inversion of the lid, from contraction of a cicatrix in the conjunctiva, may be counteracted, by destroying with caustic, or removing with cutting instruments, a portion of the outer integuments, corresponding to the internal cicatrix. Forceps with broad points are used for taking up a fold of the skin, and an oval portion is then excised with a knife or scissors, cutting instruments being less painful and more precise than caustics. Of the latter, the sulphuric acid has been particularly recommended for this purpose. The contraction of the wound releases the cilia from the power of the internal cicatrix, and the parts are restored to their healthy state.

The term Pterygium is employed to denote a thickened and vascular

state of part of the conjunctiva. The diseased portion is generally of a triangular form, commencing at the inner corner of the eye, extending towards the cornea, gradually diminishing in breadth, and terminating in a sharp apex, either at the margin of the cornea, or somewhere between its margin and centre. The thickening is seldom great, but the vessels which traverse the thickened part are numerous, enlarged, and tortuous—are, in fact, varicose. The base of the pterygium is always on the circumference of the eye, generally at the inner corner, and its apex is seldom, if ever, situated beyond the centre of the cornea: frequently the sclerotic conjunctiva alone is affected. The motions of the eye are little disturbed by the disease, but vision is materially impaired when a considerable part of the cornea is covered. Pterygium is in general single, but sometimes, though very rarely, there are two or more pterygia in one eye; and, in such cases, the patient’s vision is seriously affected, in consequence of the apices of the different pterygia uniting and coalescing on the cornea, and investing the greater part of that organ with a thick and dark shade. When several occur, they sometimes unite throughout their whole extent, and cover the half or more of the eye. This disease is very common amongst negroes and persons residing in equatorial climates.

When the pterygium is of considerable size, extending over the cornea, the only remedy is excision. The apex of the web is laid hold of and pulled outwards by forceps or a hook, and the whole diseased part is then carefully dissected off with scissors, the incisions commencing at the apex, and being carried on to the base. The wound gradually contracts; and though an opaque cicatrix must form on the corneal surface, the speck is of much less dimensions than the space formerly occupied by the pterygium. If the web be thin and not exceedingly vascular, it may be sufficient to make a semicircular section of it transversely, by means of a hook and scissors, between its base and the margin of the cornea; its growth is thereby arrested, and there is a probable chance of its beginning to diminish, and ultimately disappearing. When it is small, and so situated as to cause no impairment of vision, it is prudent and good practice not to interfere with it at all.