PINGUECULA is a small, yellowish ele vation in the bulbar conjunctiva near the corneal limbus and usually situated to the inner side. It is composed of con nective tissue and elastic fibres, in asso ciation with a colloid substance; it is due to the action of external irritants. It has no significance beyond its cosmetic effect, except that it may originate pte rygium.
Pterygium.
Symptoms.—Pterygium consists in a triangular fold of hypertrophied con junctival and subconjunctival tissue of fleshy appearance, generally- situated to the inner side of the cornea in the pal pebral fissure. It may, however, be on the outer side of the cornea and in the traumatic variety may entirely surround the membrane. The apex of the triangle or the head of the growth is attached to the cornea, while the base spreads out like a fan into the semilunar fold. The neck of the growth lies between the apex and the base and corresponds to that part which lies on the limbus.
At times the pterygium may push its way across the cornea and disturb vision by involving the pupillary area of that membrane. But usually, however, it shows no tendency to advance into the cornea.
In its early stages the growth is thick and fleshy in appearance; but it becomes paler after a time and its blood-vessels are reduced to fibrous cords, giving the structure a tendinous appearance.
Pseudopterygium may always be diag– nosed from the true variety by the fact, that a probe may be passed under the neck of the latter, whereas this proced ure is impossible in pseudopterygium, owing to the matting together of the tis sues by the preceding inflammation.
Etiology.—Pterygium never occurs in children, although it is not an uncom mon disease of adult life. Fuchs thinks that its starting-point is usually a pre existing pinguecula, and that it is due to the prolonged influences to which the conjunctiva in the region of the palpe bral fissure is exposed. It is especially common among persons who are sub mitted to the inclemencies of the weather: sailors, coachmen, farmers, and others.
Pseud opterygium, or traumatic pteryg ium, occurs as a result of some inflam matory process which causes a lesion of the margin of the cornea. This variety
is especially liable tG form after burns or marginal ulceration occurring in puru lent conjunctivitis or phlyctenular dis ease, Treatment.—If the pterygium be small and shows no tendency to involve the cornea, it should be allowed to remain, for its removal for cosmetic purposes will be unsatisfactory, owing to the scar which remains upon the cornea and con junctiva.
A pterygium may be removed either by excision or by ligature. In the former method the head of the growth is grasped with fixation-forceps and is dis sected off from the cornea by a sharp knife. This being accomplished, the growth should be separated from its base by two converging incisions. After the removal of the pterygium, the edge of the wound should be carefully united by sutures. If the growth be very large, it may be split into an upper and lower half after its dissection from the cornea, and the flaps thus obtained transplanted into the superior and inferior Electrolysis is of value in the early stages of pterygium, in a strength of 3 milliamperes, the needle (connected with the positive pole) being inserted at right angles to the axis of the growth. H. M. Starkey (Jour. Amer. Med. Assoc., Sept. l7, '95).
A simple procedure in the treatment of pterygium described by A. Coe is cau terization of the head of the -membrane by means of a platin-um wire, with a fine bulbar end, not larger than a very small pca, and heated in an alcohol-lamp. Practically complete cure obtained in an extensive pterygium by three cauteriza tions of this kind, carried out at inter vals of a few days. At the end of sev eral months it was possible to make out only a light opacity, corresponding with the thickening in the conjunctiva, while the nearer tissues were entirely trans parent. The same treatment in 24 cases, with invariably good results, ex cepting in one patient, who presented a very extensive pterygium with large vascularities. F. B. Loring (Semaine Med., No. 34, 1902).
Injuries of the Conjunctiva.