CANCER. DISEASES CARUNCLE. Hypertrophy. Apply tinct. opii, or CANCER. Medullary and melanotic growths occasionally spring from the conjunctiva. Several cases of the kind are recorded by M. Wecker.* DISEASES OF THE CARUNCLE.-The caruncula lachrymalis is a small, reddish, conical body, situated at the inner canthus of the eye. It is composed of a mass of Meibomian glands, and is covered by a continuation of the conjunctiva. A few fine hairs grow from its surface. The caruncle participates in all the affections to which the conjunctiva is subject, and in some few cases it becomes chronically enlarged, looking like a small mass of florid granulations springing from the inner angle of the eye. Under these circumstances it may extend itself behind the upper and lower lids, and if touched is apt to bleed. Tincture of opium applied to the enlarged gland cup. sulph. every day, by means of a camel's-hair pencil, usually effects a cure in such cases; or it may be necessary to smear it with sulphate of copper. It is not advisable Must not be if it can be avoided to excise the superfluous growth, because, should the caruncle subsequently become atrophied, the lachrymal puncta are displaced inwards, and troublesome epiphora, with its consequences, excised. occurs. A polypus springing from the caruncle should be snipped off with a pair of scissors, and the surface from which it grew touched with caustic; a little bleeding is apt to occur after this little operation, but a sponge pressed firmly over the corner of the eye for a few minutes will stop the hæmorrhage, and the application of the caustic will tend to the same end. "Maladies des Yeux," tom. i. p. 199. See also a case in "Handy-Book of Ophthalmic Surgery," by J. Z. Laurence and R. C. Moon, p. 60. CHAPTER VIII. DISEASES OF THE CORNEA. General pathology-Vascular opacity-Keratitis- bodies-Arcus senilis-Tumours. -Abra BEFORE Commencing the consideration of the various GENERAL diseases of the cornea, it will be well to take a gene- PATHOral view of the pathological changes to which it is liable. The cornea we know to be a non-vascular structure; and formerly, when hyperemia was regarded as the first and most essential step in inflammation, it was difficult to see how the cornea could be the seat of it. But now that we have learned to look rather to the elements of a tissue as the point of departure for inflammatory changes, and to regard vascularity and hyperæmia, however important, as accessory phenomena, the cornea becomes one of the most appropriate tissues for the study and illustration of the modern doctrines of cellular pathology. LOGY. tory Inflammatory changes, then, begin in the cornea, as Nature of in other parts, with a rapid multiplication of the inflammacellular elements of the tissue, and the migration of changes. leucocytes from the neighbouring vessels. In slighter cases this process may be superficial, and limited to the epithelial layers; but in severer ones, the corpuscles of the proper corneal tissue, beneath the anterior elastic lamina, take part in the proliferation. This multiplication of cellular elements, either in the Causes of opacity. Formation of vessels, and pus. VASCULAR CORNEA. Contrasted epithelial or deeper layers, or both, together with corresponding changes in the intercellular material, are the principal causes of the opacity which marks the early stages of what we must still call inflammation of the cornea. This opacity may amount either to a superficial haziness from a ground-glass surface, or it may be of a deeper interstitial kind. The new, dense, opaque formations of "pannus or vascular opacity of the cornea, are referrible to the development from cellular elements of a kind of connective tissue. In all cases the formation of vessels is secondary, and takes place chiefly by extension from the vascular textures around. It has been traced to the transformation of fusiform cells near the margin of the cornea, and their coalescence with similar structures in the conjunctiva. Lastly, the formation of pus, as in suppuration elsewhere, is due to a rapid production of cells of a lower grade, and the degeneration and deliquescence of the intercellular substance, together with the appearance of numerous leucocytes from the surrounding bloodvessels; these cellular elements may escape from the surface, as in ulceration, or be confined between the corneal lamellæ, and constitute an abscess. PANNUS, OR VASCULAR OPACITY OF THE CORNEA.OPACITY OF Although pannus may be the result of keratitis, or inflammation of the cornea, the distinction between them is obvious enough, for in the former affection the cornea is usually uniformly opaque, as though covered with an adventitious coating, and the vessels branching over it are large, tortuous, and distinct from one another, the sclerotic and conjunctiva being only slightly congested. In keratitis, on the other hand, the opacity of the cornea is partial and of a ground-glass appearance, obviously from changes in the corneal tissue itself; its circumference is surrounded, to a greater or less extent, by a zone of very minute vessels, which advance only a slight distance from the margin towards the centre. The sclerotic zone of vessels is also well marked in the active stage of the disease, and the conjunctiva is more or less congested. with keratitis. Sometimes follows it. In some few cases of keratitis, large tortuous vessels extend themselves over the cornea, but in these instances the invasion is generally rapid, by extension from the conjunctiva; the patient complains of con siderable pain in the eye, and ciliary neurosis, and the cornea is uniformly hazy. As the disease becomes chronic, the pain subsides, and the congestion of the sclerotic and conjunctiva disappears, but the cornea remains opaque and vascular-in fact, pannus may then be said to exist. tion; Ulceration of the cornea may give rise to pannus; in May arise almost all instances of healing ulcers, a vascular band from ulceracan be traced from one or more points of the circumference of the cornea, extending towards the ulcer; and if the parts remain in a state of chronic irritation for some time, the vascularity of the cornea may continue, especially if that portion of it formerly occupied by the ulcer remains uneven, and therefore a source of irritation. But inflammation and ulceration of the corneal more often from granutissue are by no means the most frequent causes of lar lide. pannus; vascular opacity of the cornea more often arises from the effects of chronic granular conjunctivitis, the palpebral surface of the conjunctiva having been rendered uneven from the cicatricial tissue which has formed, and being a source of constant irritation as it traverses the cornea in the movements of the parts. Under these circumstances, the superficial layers of the cornea often become opaque, and large tortuous vessels gradually extend themselves over its surface. The thickness of this vascular layer will of course vary in different cases; in some instances it is Density of so dense that even the outline of the cornea cannot be vascular distinguished from the sclerotic, while in others, the iris and pupil may be dimly visible through the semiopaque and vascular cornea. layer. Pannus sometimes occurs as a sequence of suppu- Other rative or diphtheritic conjunctivitis, depending, as in causes. the last case, on the destructive changes which have taken place in the palpebral conjunctiva. The same result may follow the prolonged action of any other mechanical irritant as, for example, inverted eyelashes, whether arising from trichiasis or entropium. The Treatment of vascular opacity of the cornea will Treatment. naturally depend very much upon the cause of the disease; for instance, if arising from trichiasis, or entropium, the inverted cilia or margin of the lids must be either removed, or restored to their normal Remove position, before we can hope to overcome the disease; the cause. Ꭱ If lids contracted, Elongate palpebral fissure. Excite purulent inflammation. Precaution as to health. Inoculation. and if we can only succeed in getting rid of the source of irritation, we shall have every reason to expect that the state of the cornea will rapidly improve of itself. In many instances of pannus, consequent on granular or diphtheritic conjunctivitis, the contraction of the cicatricial tissue following these affections of the eye shortens the lids from side to side, so that they press unduly and irregularly against the eyeball; this, together with the roughness of their surfaces, makes them act somewhat like a rasp against the cornea during the movements of the eyelids. Under these circumstances we must endeavour, in the first place, to correct this shortening of the eyelids, and for this purpose it will be necessary to divide the external commissure as described at p. 108. By this proceeding we not only elongate the palpebral fissure, and directly relieve the pressure exerted by the contracted eyelid on the cornea, but having divided some of the fibres of the orbicularis muscle, we weaken its action, and this again tends to lessen the pressure of the lids on the eye. Provided we can, by this simple proceeding, sufficiently relieve the friction of the palpebral conjunctiva against the diseased cornea, the pannus will probably disappear to a very great extent without further treatment; this desirable result is, however, frequently very materially hastened if tannin be dusted freely over the cornea every morning, until the opacity of the cornea diminishes, when the tannin may be used every three or four days. Supposing, however, that no favourable results follow this treatment, or that the condition is due to some other cause than contraction of the eyelids, we may still hope to improve the state of the cornea, by inducing purulent inflammation in the diseased eye. The more vascular the cornea, the less danger is there of the suppurative inflammation being followed by ulceration. The state of the patient's general health should be attended to before submitting him to this plan of treatment, for if he happens to be in a weak condition, sloughing of the cornea is very apt to occur. There is seldom any difficulty in exciting purulent inflammation in the diseased eye; but in some few instances the conjunctiva has been so completely altered in character, after long-continued granular |