KERATITIS. — Gr., Kipac, cornea, and uric, inflammation.
Definition.—Infiammation of the cor nea.
Varieties.—The varieties of keratitis are interstitial, neuropathic, malarial, dendritic, herpetic, punctate, phlyctenu lar, bullous, pannous, traumatic, striate, suppurative, and xerotic keratitis.
Symptoms.—The most constant symp tom is opacity; and this may be the only objective symptom present. It may vary from the slightest increase of the hazi ness that is visible in the normal cornea, under strong oblique illumination, with a good magnifier, to complete opacity through which no trace of the iris or pupil is visible. The opacity always causes impairment of vision, propor tioned to the extent to which it invades the part of the cornea in front of the pupil.
Redness is manifest, not usually in the cornea itself, but in the vessels at its border, which supply it with nutrient fluid; and the enlargement of which gives rise to the pericorneal zone. In chronic keratitis, however, as during the later stages of corneal ulcer, and in pannus, trunks of considerable size may be seen arising from the vessels at the corneal margin extending on the cornea, and dividing, to be distributed to the superficial corneal layers. In interstitial keratitis great numbers of extremely small vascular loops extend from the margin into the deep corneal tissue. As the inflammation goes on to resolution, the corneal yessels atrophy and in most cases entirely disappear.
The pain of keratitis is usually severe. It may be that of a foreign body' in the eye, a smarting, burning, or severe ach ing pain. It is commonly attended with photophobia, which may become intense, and with increased lacrymation. Swell ing may occur in corneal inflammation, but it is inconstant and of little conse quence.
Loss of substance, ulceration, is a far more important symptom. In many forms of inflammation the resulting ulcer is the most significant and most serious symptom. Its characteristics are closely identified with the variety of keratitis, and will therefore be considered under the special symptoms peculiar to each variety. In all corneal nlcers, however, extension usually occurs by the breaking down of an infiltrated area; and, while active, the surface of the ulcer, when wiped with a pledget of cotton, lacks the smooth reflex of the normal corneal sur face. Before the ulcer begins to heal the points of infiltration disappear and the ulcer is said to be "clean," Its sur face, too, becomes coated with epithe lium, and, although not so even as the normal corneal surface, appears to have the same polish. As the loss of sub stance is made good with new-formed tissue, the lack of transparency in the scar-tissue gives rise to an opacity, which will be most noticeable some weeks after all signs of active inflammation have ceased. Such corneal opacity, and the possibility of perforation of the cornea, and its sequels (see CORNEA, volume ii) are the special dangers of ulcerative keratitis.
Case of aspergillus keratitis: sup posedly rare variety of corneal inflam mation. The condition is 11111(.11 more common than has been thought. It is attended by intense pain in the eye and development of a brownish or black mass within the substance of the cornea. Removal of the mass early in the ease is followed by uninterrupted cure. Fail iire to recognt. c the condition fol lowed i,loti,thing of (lie cornea and in lite of the Bill Omer. July 6, 1991).
ruitsrtriAL KERATITIS begins with photophobia. slight redness, and irrita bility of the eye. Opacity appears faintly near the middle of the cornea, involving the deeper layers, and increases from day to day, and extends toward the periph trv. Then at the border, usually the upper or lower border, the cornea be comes opaque, and fine loops of deep vessels push out in it, and extend gradu ally farther toward the centre, giving the tissue they invade a characteristic "sal nion color. Iritis or choroidal inflam mation is liable to attend this form of keratitis, and may be manifest before the opacity of the cornea wholly hides the iris and pupil. Usually both eyes are affected. The course of this form of keratitis is essentially chronic, usually running through several months, and sometimes years before it subsides. The corneal surface often becomes quite un even; but is rarely ulcerated. The dis ease generally affects both eyes; and usu ally occurs during childhood or youth, but may be met in early adult life, or even later. The patient frequently pre sents other evidences of inherited syph ilis, particularly the Hutchinson teeth, or the nasal deformity; or the symptoms may be those that are grouped under the term s.crofula.
Three cases of late hereditary syphilitic keratitis, appearing. respectively, at the ages of 20. 52, and 29 years. The cases were characteristic and gave additional proof of the fact that the absorption of the exudates in the cornea takes place all the more slowly and incompletely, the older the patients. In one instance the sclerosis was present five years after the beginning of the attack. A. Chevallereau (Jour. des Mal. Cut. et Syph., Sept., '95).
Instance of conjunctival interstitial keratitis of syphilitic origin. The case was seen directly after birth. The lids NI ere swelled, and there was a dirty yellow discharge from the conjunctiva. The cornew were dull gray. Barabasher (Vestnik of Oplithal., May-June, '96).
A condition of keratitis interstitialis annularis in an eye with increased ten sion and intense congestion. Vision equaled ability to see to count fingers at four feet. There was a ring of deep and dense opacity between one and two millimetres in width, entirely surround ing the central two-thirds of the corneal arca. The patient, a man 67 years of age, was suffering from hay fever. The acute symptoms quickly subsided under treatment, but the opacity persisted for about two months. Moniton (Annals of O., O., and July, '96).