Tattooing of the cornea should not be entered upon too lightly. One should refuse to operate in any case in which the iris is incorporated in the cicatrix. Trousseau (Ann. d'Ocul., Mar., '99).
Dionin used to clear up new and old corneal opacities. The solid drug is ap plied in (loses of about 0.0CF5 gramme (V„ grain) once, or rarely twice, a week to the conjunctiva. In this way there is not acquired that speedy tolerance to its action. The pain lasts from two to five minutes; the oedema reaches its height in fifteen or twenty minutes, and lasts from four or eight to twelve hours, or even longer. Sneezing is a common sequel, especially in adults. In those cases where the patient must be treated at home an ointment containing 10 per cent. of clionin is ordered, with directions that a small mass should be placed inside the lids and then gently rubbed. In five eases, among sixty in all, no cedema resulted. P. R. v. Arlt (Wochen. f. Therapie u. Hygiene des Auges, Dec. 11, 1902).
Cornea, Tumors of.
New growths situated wholly or chiefly in the cornea are rare. They may be of importance because of the disfigurement they produce from interference with vision or by danger of extension when of a malignant character.
Frequently tumors of the conjunctiva extend over the cornea, and so belong partly to botb regions. It has even been doubted whether primary tumors of the cornea ever occur. But well attested cases are on record. The most frequent form of corneal tumor is the dermoid, which usually starts about the sclero corneal junction and extends both ways. It is generally believed to be always con genital; but may slowly increase in size for many years; such tumors are com monly removed for cosmetic reasons.
Such tumors may be located on the cornea alone or on the sclerotic alone, but the largest number involve both, being found most frequently at the outer and lower sclero-corneal margin. They are all congenital. A. R. Baker (Trans.
Sec. on Ophth., Amer. Med. Assoc., p. 97, '96).
Malignant neoplasms involving the cornea are usually secondary.
Perhaps carcinoma of the cornea is always secondary to such growths of the conjunctiva or some more distant part. Fibroma or sarcoma may be primary.
Report of a case of fibroma removed from the cornea of a woman, aged 50, where it had been slowly growing. The margin of the cornea, about one milli metre wide, was transparent all around. The tumor was flat, whitish, and two millimetres thick. It was easily dis sected from the cornea, which was trans parent, and its removal allowed the pa tient to read large letters. The micro scope showed it to be purely fibrous, and derived probably from the corneal sub stance. D. Meigham (Glasgow Med. Jour., vol. ii, p. 223, '96).
Report of a ca.se of primary sarcoma. commencing at the corneal limbus. Twenty-two other cases found in litera ture. From a study of these, conclusion reached that sarcoma of the limbus is comparatively rare and remains confined to the external structures. Metastases( practically never occur. Recurrences are frequent, but do not justify enucleation, unless the growth has attained extensive proportions or vision has been de stroyed. A. N. Strouse (Archives of Ophth., p. 217, '97).
Corneal scars, although often perma nent, and, if large, subject to distension, very rarely become the seat of keloid changes. But a tumor of that kind is possible.
A girl suffered from ophthalmia neona torum, which left the cornea opaque. For six months the scar did not change, and then it began to grow. At two years it looked like a large staphyloma, but when examined under aumsthesia was found to be a large tumor. On removal it was found almost eight millimetres, thick. A microscopical examination showed it to be chiefly keloid. Two similar eases had been previously re ported by Simon and Szokalski. C. D. Westeott (Annals of Oplithal., p. 472, '97).