Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/845

OPHTHALMOLOGY 781 opacities here and there. The corneal surface is "steamy." The ciliary zone of vessels, immediately round the cornea, is congested, and iritis is a frequent complication. As a rule pain and photophobia are not great. The cornea seldom clears in less than a year, and even then only im perfectly. Internally, minute doses of mercurials, or where there is decided struma the syrup of the iodide of iron should be given. Locally, atropine should be used to prevent iritis. As the cornea clears, some stimulant, as the dusting of fine calomel powder, may hasten the absorp tion of the exudation. Phlyctenular Ophthalmia occurs in strumous or weakly children, especially after hooping-cough or measles. There is great intolerance of light, the slightest attempt to separate the lids causing a gush of tears. The patient is generally kept in bed in a dark room and buries his head in the pillow to exclude the light. The conjunctiva is reddened generally, but spots of localized congestion are seen near little greyish or yellowish elevations on the conjunctiva, or on the cornea near its margin. These papules or pustules may succeed each other in crops for a long time. On the cornea they give rise to vascular ulcers, which may be single or so numerous as to constitute a condition of pannus. As they heal the vessels shrink, and a small white speck is left to mark the seat of the ulcer. As regards treatment, the patient must have a shade or dark glasses, and be sent out of doors daily when the weather permits. Tonics and nourishing food are required. Locally, so long as the secretion is watery atropine must be used; later, mild astringent lotions ; and finally, to aid the healing of the ulcer and clearing of the residual opacities, some mercurial ointment or calomel powder should be applied. Ulcers of the Cornea. Ulcers occur under many forms, to which very various names have been given. All the forms have certain symptoms in common with each other and with the above diseases. There is great pain in and about the eye, great intolerance of light (especially in super ficial ulcers), and congestion of the ciliary zone. They generally leave an opacity, which greatly interferes with sight if in the centre of the pupil. In severe inflammatory or suppurative ulceration the above symptoms are well marked ; the base of the ulcer is greyish in colour, its edges irregular, and the surrounding cornea infiltrated. It ex tends superficially and deeply, and may cause hypopyon (pus in the base of the anterior chamber), and even per foration of the cornea, or iritis. The weak ulcer has little pain or congestion, and seems simply a loss of substance at one part of the cornea. It causes distorted or multiple images. Its existence is a sign of lowered health, and calls for local stimulation and tonic treatment. The small central ulcer of children is a small greyish funnel-shaped spot in the centre of the pupil, with little pain or congestion. It sometimes goes on to abscess, but usually heals quickly. The senile or serpiginous ulcer is a very serious form. There is great pain and photophobia, and unless treated the ulcer gradually eats its way across the cornea, or extends at its margins so as to isolate the central part of the cornea. The treatment of corneal ulcers varies very much with the type of disease and with its several stages. In the acute cases the eyes should be shaded, sometimes bandaged ; atropine applied locally allays pain ; eserine is said to act similarly by reducing tension, and is preferable where con- junctival discharge is aggravated by atropine. The weak ulcer should be touched with a nitrate of silver solution, the senile bathed with a quinine lotion. If the inflammatory ulcer be not checked by atropine, and if hypopyon increase, tension may be diminished by incising the cornea at its margin, or through the base of the ulcer (Saemisch), or by performing iridectomy. Abscess of Cornea may result from injury or ill-health. It begins as a yellow spot in the substance of the cornea, with some surrounding haze. It may become absorbed, or burst forwards and be converted into an inflammatory ulcer, or backwards, giving rise to hypopyon. If hot fomentations and atropine do not check it, it must be treated surgically like the inflammatory ulcer. Staphyloma of the Cornea is a bulging forward in whole or in part of the new tissue which replaces the cornea after ulceration or sloughing. It has a bluish or greyish colour, and may be slight in amount, or so great as to keep the eyelids widely separated and cause great irrita tion. When there is no irritation it may be left alone ; when it is increasing an iridectomy may check its progress. When it is large and causes irritation the eye may be removed entirely, or in part so as to leave a stump on which to fit an artificial eye. Conical Cornea occurs principally in young women whose health has been much reduced from some chronic cause. The cornea becomes thinned in the centre, and is slowly bulged forward. The condition, which is easily recognized from the glistening appearance and the conical form of the cornea, causes great myopia, which can be only imperfectly remedied by biconcave lenses obscured except at a small central aperture or slit. In severe cases opera tion may be of some service. Keratitis Punctata is usually secondary to some deeper- seated disease, e.g., iritis, choroiditis, or sympathetic ophthalmitis. Minute greasy -looking dots are deposited at the back of the lower part of the cornea, generally arranged as a triangle with its apex upwards. The ocular tension and amount of aqueous humour increase. The treatment is that of the causal disease, usually iodide of potassium or a mercurial, with atropine locally. Arcus Senilis is a whitish crescent or ring just inside the corneal margin. It is a senile change, a fatty degen eration of the corneal tissue, not necessarily accompanied by fatty degeneration elsewhere. It does not influence the healing of corneal wounds in any way. In Acute Iritis the iris changes in colour and its fibres Diseases lose their definition and look muddy. The pupil becomes ?f the small, irregular in outline, and sluggish or immobile when iris> stimulated by light. There is a pink zone of congestion round the cornea (the ciliary zone). The aqueous humour is turbid ; it may contain blood, and even pus. There is more or less pain in the eye and temple, which is usually worst at night ; there is intolerance of light, great increase in the secretion of tears, and impairment of sight. In most cases lymph escapes from the posterior surface of the iris and fixes its margin to the lens at one or more points, or all round, and may even occlude the pupil. In some cases the exudation is entirely serous and no ad hesions are formed (serous iritis). Iritis is one of the symptoms of secondary syphilis ; it is caused by rheu matism, by ulcers and diffuse inflammations of cornea, by injuries to the cornea, iris, and lens, and forms part of nearly all cases of sympathetic ophthalmitis. The syphilitic form usually involves both eyes; it produces much exudation and often little yellow nodules, and rarely relapses. Rheumatic iritis is generally serous, unilateral, and recurs frequently. Atropine must be freely applied locally to prevent the formation of adhesions, or to break down such as may have already formed. _ The temple may be leeched, and opiates given if pain is severe. In the syphilitic forms calomel must be given ; in the rheumatic alkalis and colchicum. The eyes must be protected by a shade. Traumatic iritis should be treated by continuous cold and leeching. If it is due to a swollen lens, the latter must be removed. After the disease is past the pupil is frequently irregular from adhesions (synechiae) of the iris to the lens-capsule. If adhesions have been broken down