Abscess and Ulcer of the Cornea are usually the result of injury to the eye—a stroke from a piece of coal, for example; or they occur in persons in depressed states of health. They have the appearance of white spots in the clear part of the eye. In the case of the ulcer, by looking carefully from the side one may see that part of the substance of the cornea has been destroyed, and that there is a little hollow on the surface. When the abscess passes deeply into the substance it may open into the anterior chamber of the eye (p. 448), into which matter drops and in which it collects. When this has happened, if the person is made to look up, the yellow matter is seen at the lower border of the transparent part. Sometimes an abscess or ulcer spreads over a large part of the cornea, so destroying it that a large•part of it breaks down and separates. In cases where an ulcer has eaten its way through the whole depth of the cornea, it is not uncommon for the coloured part of the eye—the iris—to be pushed for wards and a part of it to bulge through the opening and appear as a little roundish bleb. This is called hernia of the iris. When it occurs it seriously delays recovery and injures the chances of a seeing eye being left. After healing and closing of the ulcer the iris remains caught in the scar, and thus the curtain of the eye becomes attached to the transparent cornea in front. Eye surgeons call this condition an terior synechia.
The symptoms of abscess and ulcer are in tense pain, redness and watering of the eye, and on opening the lids the changes going on are quite apparent.
Treatment.—Apply warm cloths. Carefully abstain from using any irritating what ever, such as sulphate of zinc wash or sugar of lead wash, &c. Let fall daily into the eye one or two drops of the solution of atropine (2 grains to the ounce). At night paint over the eyelids with belladonna, as directed on p. 479, and let the paint be bathed off in the morning and warm cloths again used. An occasional blister on the temple will help to relieve pain. The person ought to be well nourished, and if in weak health ought to have quinine and iron tonics, cod-liver oil, or syrup iodide of iron (from half to one tea-spoonful, according to age). If matter appears inside the eye, an operation must be performed for getting rid of it. Abscesses and ulcers are, however, so serious that from the first a competent surgeon should be consulted.
White spots, opacities, on the clear part of the eyeball, are frequently left as marks of inflammation, abscess, or ulcer. Parents often notice that their children suffer from "weak eyes," as they say—that is, the eyes are red, and watery, and the child avoids the light; but they think nothing of it till they observe "a scum growing over the sight." This simply means that inflammation has been permitted to go on neglected, and the part has lost its transparency and become cloudy. In children something can sometimes be done to diminish the white cloud, but it is not often it can be made entirely to disappear. In grown-up per sons these white spots cannot be removed at all. Many people are also under the delusion that the whiteness is caused by something that has "grown over the sight," and can be cut or scraped off. This is a mistake. It is no new thing added to the front of the eyeball, it is simply a part of the cornea that has become white owing to inflammation. If these opaci ties, as they are called, are to be avoided, it is by having each eye carefully attended to as soon as there is the least evidence of anything wrong.
Treatment.—Bathe the eye with an infusion of chamomile flowers, weakened by the addition of warm water. When the white cloud pre
vents sight, the eye can frequently be improved by an operation for forming an artificial pupil, called iridectomy, which consists in making an opening in the cornea, passing in a fine forceps, seizing and pulling out a part of the curtain of the eye—the iris—and snipping it off with scissors. An oval opening is thus made hi the iris, through which light can pass. This is very successful in restoring sight when the opacity occupies the centre of the cornea, leaving a broad clear margin, and when the eye is other wise healthy. The result of the operation is simply to make a new pupil ; and of course the place which affords the most room for this is selected, provided it is in such a position as to be quite uncovered by the lids when the eye is open. Another case also very favourable for the operation is where the opacity is largely one sided, leaving the other side clear. But when the whiteness extends over nearly the whole of the cornea, no operation is likely to do much good.
Staphyloma is the ilroper term applied to the condition shown in Fig. 197. As a result of if flit in 'nation the cornea be comes cloudy and weakened, and yields before the pressure within. The bulging is often so great that the eyelids cannot close over it. It is very disfigur ing, and sometimes it is best to nave the eye ball entirely removed. Its presence often is a source of weakness to the sound eye, and on that account its removal is still more desirable.
Foreign bodies in the cornea are very com mon among miners, iron-workers, and people of similar employment. Fire in the eye is the usual phrase they have for such things. If the foreign body is loose within the eyelids, it is to be removed in the manner described on p. 478. But frequently small particles stick in the sub stance of the cornea, and require removal by means of some sharp instrument. In every large work there is usually one man specially skilful in removing such bodies, but frequently the most some of them succeed in doing is to scratch the cornea in various directions and set up serious inflammation. No one should attempt to remove such a body except with the clearest light. Often when the most careful examination in the ordinary way fails to reveal anything on the eyeball, the use of a large hand-lens to focus the light on to the cornea will show the speck. Specially if the person look sideways over the surface will he see the presence of any irregularity of the surface. Eye surgeons have special lance-pointed needles, set in handles, for removing foreign bodies. The patient sits fachig a window, and his head is to be firmly held by someone behind. The operator sits directly opposite the patient, and opens the eye with the forefinger and thumb of the left hand, fixing the eyeball by slight pressure with finger and thumb. 116 must never scrape at random, but cause the patient's head to turn, or cause him to turn his eye, so that the light falls in such a way as distinctly to show the foreign body. The needle is now to be deliberately and carefully placed down at the side of the body, and moved so as to turn it out; and this repeated till the object is removed from its fixed position, when the lid moved over the place by the finger may finally remove it. No sudden scratches must be made, one after the other, in the hope that one of them will effect the desired purpose. If good daylight cannot be obtained the person should be set down at the side of a gas bracket, which can be moved to cast the light on the eye in the way best fitted to show the foreign body, and a hand lens used to throw a strong beam of light.