For the rarer forms of neuropathic and malarial keratitis the prognosis must depend considerably upon the general condition of the patient. There is some dang,er of relapses; and it must not be forg-otten that ulcers from this disease are liable to infection, with all the con sequences thereof. At the best they are likely to leave the affected portion of the ecrnea nebulous and irregularly astig matic. Herpetic ulcers, unless greatly neglected, commonly leave no trace. Punctate keratitis usually leaves the cor nea slightly damaged; and the syphilitic form is very chronic, with quite incom plete resolution.
Phlyctenular keratitis, if carefully treated. commonly leaves very little per manent damage of the cornea. Rut, oc curring in the children of the ignorant and careless, it is very often neglected; Fo that a large proportion of the nebulous eorneas with high, irregular astigmatism are due to it. It is extremely liable to relapse; but the single attack yields promptly to treatment, or terminates often within two or three weeks in spon taneous recovery. The tendency to recur is the serious feature of bullous kora titis. But permanent complete recovery may occur in the cases due to trauma tism.
Panntis rarely ends in complete recov ery. I t depends largely on the condition of the lids. If these can be rendered smooth and do not press upon and rub the cornea, it will get comparatively clear, and free from vessels. But some irregular astigmatism always remains. Fortunately the disease does not usually involve the part of the cornea in front of the pupil; so that normal vision may be retained. Striate keratitis usually clears up entirely in a few days or a few weeks. In other forms of traumatic keratitis the prognosis depends on the situation and extent of the loss of sub stance.
In suppurative keratitis there is always more or less permanent opacity; which is of serions or slight importance accord ing to its situation. The density of the opacity is somewhat proportioned to the depth of the ulcer causing it. The dan ger of extension in an infected ulcer is indicated by infiltration of its margins or base; that is, by the extent to which the process is invading new tissue. When this extension ceases, when the ulcer be comes "clean," improvement is to be ex pected. Ulceration is particularly dan gerous to the cornea, because it is non vascular; and when, in the course of an ulcerative keratitis, vessels extend out from the limbus, and invade the floor of the ulcer or the tissue immediately around it, the danger of perforation passes away. Perforation, with prolapse of the iris into the opening, always causes a permanent leucoma, which is serious according to its size and location (see CORNEA, OPACITIES OF, volume ii). Stip
purative disease of the cornea is often the starting-point of an infection that ends in panophthalmitis, or a slower inflammation of the uveal tract, and chronic degenerative changes. And per forating ulcer may ultimately cause sym pathetic disease of the other eye.
Treatment. — While the removal or treatment of the special causes varies with the different forms of keratitis, cer tain general principles are applicable to the treatment of all kinds of corneal in flammation. In the first place, the gen eral health of the subject has much to do with the resisting power of the cor nea, and should be guarded and built up in every way. This does not mean that stimulants should be used in the ma jority of cases. But it does mean that the patient should have sufficient nour ishing food, fresh air, enough exercise to keep the circulation and respiration active, sunlight and the influences of cheerful surroundings, and plenty of sleep. To secure sleep it may be neces sary to give analgesics; but these should be given in small doses, and only to sup plement the influence of fresb air and exercise. It may be well to give a laxa tive, when needed to promote digestion; but active purgation should be avoided. Tonics may be indicated, and full doses of tincture of the chloride of iron seem to have a distinct influence in checking suppuration.
Local measures must be such as to support, not impair, the vitality of the part. On this account cold applications must be avoided, even where they would be indicated if it were not for the cor neal lesion. On the other hand, any thing that will keep the eye continuously warm and moist, acting like a poultice, is liable to be injurious. Applications of hot fomentations for a few minutes at a time, or the more continuous applica tion of dry heat, may be beneficial. The danger of its poulticing effect should generally exclude the bandage; but un der certain circumstances it may be best to use it. These are: in neuropathic keratitis when the slight traumatisms to which the cornea is exposed when the eye is open decidedly aggravate the trouble, and when there has been an injury causing a clean loss of the corneal substance,—an uninfected ulcer. The eye should be kept closed, in any case of corneal ulcer, when exposed to dust that would be likely to lodge in the cav ity or be pushed into it by the normal movements of the lids.