WOUNDS AND INFLAMMATION OF THE MEMBRANA NICTITANS.
Like other parts of the ocular apparatus, the third eyelid and gland of Harder are subject to accidental injuries of various kinds. What is worse, ignorant persons seeing the cartilage and membrane projected over the eye in ophthalmias and tetanus, have mistaken it for a morbid product and deliberately cut it off in part. The condition of the organ may be ascertained by parting the lids with the fingers and pressing gently on the front of the eyeball, when the nictitating membrane will be fully exposed.
If detached portions cannot be restored, but threaten to slough, or cause distortions or unsightly and irritating neoplasms they should be seized with forceps and snipped off with scissors. Otherwise the treatment consists in soothing astringent and anodyne Collyria as in conjunctivitis.
TUMORS AND HYPERTROPHY OF THE MEMBRANA NICTITANS.
Neoplasms of this organ may occur in any quadruped or bird and may be recognized by the swelling of more or less of its substance, by the unevenness of its free margin, or by distinct outgrowths from its surface. They are especially common in dogs and pigs and may be fibrous, epithelial or otherwise. The treatment is purely surgical and in case of a malignant neoplasm should demand the removal of the entire organ.
ADENOMA OF THE GLAND OF HARDER.
Cases in dogs have been recorded by Fröhner and Schimmel, and it might be expected in other carnivora, ruminants, pigs, rabbits and birds. The treatment is by excision with forceps and scissors, and subsequent treatment with an antiseptic zinc lotion.
FOREIGN BODIES IN THE CONJUNCTIVAL SAC.
Frequency: seeds, glumes, awns, dust, sand, wood, metal; exudate; in conjunctival pouch, under nictitans, in puncta. Filaria lachrymalis. Symptoms: closure of lids, epiphora, congestion, inflammation, infection. Treatment: local anæsthesia, forceps, lead pencil, pin’s head, collyria.
So common are foreign bodies in the conjunctival sac of the domestic herbivora, that in any case of epiphora, hyperæmia or inflammation of the mucosa, the first care should be given to see that the condition is not caused by the presence of such an irritant. In animals fed from high racks, seeds and glumes of the gramineæ, awns of barley, and dust of various kinds often get into the eye and stick fast. Under other conditions, insects, particles of sand, dust, wood, metal, etc., prove equally injurious by their presence. Awns and chaff are particularly liable to adhere to the mucosa and even to become covered by an exudate, which renders them more firmly adherent. Other objects lodge under the eyelids, or membrana nictitans, or in folds of the mucosa. Their entrance into the lachrymal puncta has already been referred to. The larger and more rounded bodies are likely to be washed off by the excessive flow of tears, assisted by the movements of the nictitating cartilage, but flat glumes, or awns stick too closely to the surface, while the smaller objects become entangled beneath the lids, or hair, or in the folds of the mucous membrane. The filaria lachrymalis may be the cause of trouble.