Part 65

A second resort is to distend the canal by a liquid injection thrown into the nasal opening. This will succeed when the obstruction is only caused by concretions in the canal.

A somewhat similar resort is the insufflation of the duct by means of a finely pointed tube inserted from below into the nasal orifice of the duct.

Still another method is to make a new opening for the escape of the tears into the nose. When the stenosis is at or near the nasal opening of the duct, an artificial opening is easily made and usually satisfactory. Under anæsthesia, a sterilized silver probe is passed through the upper punctum, the sac and canal. When it meets definite obstruction its position is ascertained inside the nose, and an incision is made so as to allow its escape. The constant escape of tears tends to prevent it from closing up again, but it is well to examine into this until it has thoroughly healed. A silk thread worn in the duct and held in place by a copper or aluminum ring on each end may be resorted to.

Attempts have been made to establish a new outlet by boring through the lachrymal bone into the nose, but without a permanent success. It has also been advised to obliterate the lachrymal ducts and sac, on the one hand and to excise the lachrymal gland on the other, but the proposed cure is worse than the disease.

DISEASE OF THE LACHRYMAL CARUNCLE.

The caruncle is inflamed in conjunctivitis. When this inflammation leads to hypertrophy it is known as encanthis. This is a common condition in dogs and the caruncle may increase to the size of a pea or acorn, and by compressing the canaliculi it leads to a profuse overflow of tears on the cheek. At first there is the acute congestion of conjunctivitis, but later there may be induration and pallor.

The treatment of this condition consists in astringent and sedative collyria in the early inflammatory stages, and later in the ablation of the hypertrophied mass. The caruncle is seized with a pair of rat-tooth forceps and snipped off with curved scissors, the free bleeding being afterward checked by cold water.

In cases that seem, by reason of excessive vascularity ill adapted to this method, the hypertrophied mass may be tied at its base with a stout silk thread so as to cut off the supply of blood, and cause it to slough off. A collyria of boric acid (4 per cent.) or mercuric chloride (0.02 per cent.) may be used to prevent infection.

=Tumors= of the Caruncle are met with, such as fibroma (Wörz), Sarcoma and Melanosarcoma. For all alike the complete extirpation of the neoplasm is demanded.

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.

Symptoms. There is closure or semi-closure of the lids, the escape of a profusion of tears over the cheek, and active congestion or hyperæmia. A careful examination with everted lids, or even with raised nictitans will usually reveal the foreign body. If overlooked or neglected the hyperæmia rapidly advances to active inflammation, with or without an infective complication. Foreign bodies blown into the eye, as a rule carry with them more or less bacteria, and, if these have any tendency to pathogenesis, the irritation of the mucosa easily paves the way for their colonization. Thus, any grade or form of conjunctivitis may supervene upon the introduction of a foreign irritant.

Treatment. Nearly all such bodies are most easily and certainly removed by a pair of fine forceps. It may be necessary to first anæsthetize the eye with a 5 per cent. solution of cocaine. The clean tip of the finger passed under the lid and nictitating membrane is a safe and effective method. Less effective methods are to pick up the offending body on the point of a lead pencil, or a small, blunt metallic spud, or with a pin’s head covered with a clean pocket handkerchief. This may be followed by an antiseptic (boric acid) collyria, with or without cocaine or morphia.

WOUNDS OF THE CONJUNCTIVA.

These occur in all domestic animals, but are especially frequent in dogs and cats from scratching with the claws. In clumsy handling of the eyelids, the mucosa is wounded by ragged and uneven nails. Injuries and stings by insects which are attracted by the reflection from the eye constitute a specially grave lesion, often proportionate to the nature of the poison instilled.

Symptoms. There are usually closure of the eyelids, with exudation and thickening of the conjunctiva especially in the vicinity of the wound, a free flow of tears, mingled it may be with blood, and the visible evidence of the lesion on the exposure of the injured part. If the cornea is implicated, even the pupil is contracted, showing photophobia.

Treatment. Slight noninfected wounds will heal readily under simple astringent collyria, following upon the removal of any cause of mechanical irritation. A solution of corrosive sublimate, 1:5000, or of boric acid, 4 per cent. may be used. If photophobia exists ½ per cent. of atropia sulphate or 1 per cent. of cocaine hydrochlorate will usually give relief. Extensive wounds may require sutures, and sloughing tissue may be excised with fine curved scissors. Excessive granulations may be removed in the same way. For stings use a potassium permanganate solution (2 grs. to 1 oz). Violent inflammation may be met by a laxative and by leeching the periorbital region.

BURNS OF THE CONJUNCTIVA.

Burns may occur in all domestic animals from acids, alkalies, quicklime, carbolic acid, boiling liquids, etc. The cornea usually suffers, being the part most exposed. The caustics cause swelling, blanching and finally exfoliation of the epithelium, or even of the superficial layers of the cornea. In burns by hot liquids vesication may be present. If the destruction extends deeply into the cornea there may be escape of the aqueous humor and destruction of vision. If less penetrating, there may still develop vascularity, and permanent opacity by reason of the formation of a cicatrix or a change of structure in the layers of the cornea, or, in dogs especially, adhesion of the cornea to the eyelids (symblepharon). In the early stages there is closure of the eyelids, with swelling, profuse lachrymation, and photophobia.

Treatment. The first object is to remove or neutralize the offending body. Thus sulphuric or other mineral acid would demand a free irrigation with a 1 per cent. solution of carbonate of soda or potash. For alkalies, carbonated water, or a 4 per cent. solution of boric acid may be employed. For lime, Gosselin recommends free irrigation with saccharated water. The first step, however, should be to wipe out the particles of lime with a soft rag soaked in oil.