Part 64

PERIOSTITIS OF THE ORBIT.

This may be shown by the firm swelling of the bone and, in case a wound has been formed, by the contact of the probe with the denuded, hard, rough bone. When thus exposed or necrosed on the surface, or when an exostosis has formed, the bone may be laid open and scraped down to the healthy tissue, and then dressed with antiseptic pledgets.

TUMORS OF THE ORBIT.

These may be of different kinds, as =sarcoma=, =encephaloid=, =osteoma= and =actinomycosis=. They demand thorough surgical treatment, except perhaps in the case of the latter, which may recover under iodide of potassium. Emmerich records an extensive sarcoma of the orbit in a cow, weighing six pounds and extending into the nasal sinuses, and chambers, and implicating the cerebral meninges. Möller records cases of sarcoma and carcinoma of the orbit in horses and dogs, and Leblanc in cattle. Melanosarcoma is not uncommon in the orbits of gray horses which are changing to white.

Exotoses are common around the orbits of cattle.

If such growths do not show on the surface they cause a more or less unsightly protrusion of the eyeball, owing to the presence of the neoplasm in the depth of the orbit, and the removal of the bulb becomes a necessity.

DISEASE OF THE LACHRYMAL GLAND AND DUCTS. DACRYO-ADENITIS.

Even in man these parts are remarkably free from disease, while in the lower animals, we have literally no record of such conditions. Inflammation of the gland (dacryo-adenitis) would be manifested by a sensitive swelling under the outer part of the orbital process, and upper eyelid and by lachrymation, and obstruction of the gland duct and by a tense transparent rounded swelling inside the lid. A fistula is possible from a penetrating wound of the lid in the same situation. In both of the latter conditions an opening made through the palpebral conjunctiva will allow the discharge of the tears in the proper place, and healing of any external wound may be hastened by suture or plaster.

OBSTRUCTION OF THE LACHRYMAL PUNCTA. ATRESIA. INFLAMMATION.

Congenital atresia of these puncta has been recorded in foals, by Hollmann and obstruction as the result of inflammation, by Lafosse, Verjaus and Tyvaert, and of the entrance of the seeds of bromus by Stockfleth.

Apart from congenital atresia and impaction of foreign bodies the symptoms are those of conjunctivitis, with escape of tears over the face (epiphora). Injection of aseptic water into the lower puncta and its escape by the upper, and by the nasal orifice, will determine the patency or otherwise of the various channels.

Treatment consists in astringent collyria to check the inflammation, in the removal of any foreign body, in the dilation or slitting of the lachrymal canaliculi, and in case of complete atresia, in incising the lachrymal sac. Slitting of the canaliculi is accomplished by a small probe pointed bistuory (canaliculus knife). The lid is drawn away from the carnucle, and the probe point inserted at first downward, then inward and backward, and when it is well inside the sac the handle is brought to the vertical and the walls of the duct slit open.

In case of atresia Leblanc recommends to seize the inner canthus with rat tooth forceps so as to include the structures about the sac and to plunge the bistuory directly into the sac. Then by the aid of a whalebone staff he passes three silk threads through the duct and fixes them in place by attaching them to a copper ring at each end. This is retained in place and moved daily until the passage has been definitely healed and its permanency assured.

WOUND AND FISTULA OF THE LACHRYMAL SAC.

The lachrymal sac, which receives the tears from the canaliculi, is situated in the infundibulum at the upper end of the lachrymal canal and is in great measure protected against external injuries by the prominent orbital edge of the lachrymal bone. Yet violent blows with or without fracture, sometimes lead to rupture of the mucous walls and the formation of a fistula. Wounds made with penetrating bodies, more or less pointed are also liable to involve the sac. The fistulous orifice may be through the skin at the inner canthus or through the mucosa by the side of the carnucle. The cutaneous opening may be a minute orifice from which tears and muco-purulent matter escapes, to mat together the hairs on the side of the face. Sometimes there is a reddish elevation, the size of a pin head, and in fistula through the mucosa this is the rule, and the orifice is elevated so that the tears flow out over the face. For the symptoms of the attendant catarrh of the sac see below. In infected cases with obstruction of the lachrymo-nasal duct, it has been known to extend to the bone and even to open into the sinuses, or tooth follicles. (Gerard, Leblanc).

The condition is found in horses, cattle and dogs.

Treatment. In fistula resulting from simple traumatism, nothing more may be requisite than rest and soothing astringent applications. Sutures are sometimes resorted to but are liable to cause itching and do more harm than good. It is above all important to keep the lachrymo-nasal duct patent, and for this purpose a lead or silver stilet, or a thick catgut suture may be worn in the canal until healing has ensued.

CATARRH OF THE LACHRYMAL SAC. DACRYOCYSTITIS.

Connected above through the canaliculi with the conjunctiva, and below through the lachrymal duct with the nasal chamber this cavity is liable to be more or less implicated in all cases of nasal catarrh and conjunctivitis, (strangles, canine distemper, influenza). If the lachrymal duct is obstructed so that the tears accumulate in the sac, the tendency to catarrh is further enhanced by the distension and weakening of its walls, and by the propagation of bacteria which have entered with the tears, and find in them a favorable and abundant culture medium; the diameter of the sac in the horse being about ⅔rds. of an inch. The presence of foreign bodies is another cause.

Lesions. Symptoms. Swelling at the inner canthus, which raises the carnucle above the normal level, and the escape of tears over the lower lid are the most prominent symptoms. If the swelling is pressed it subsides, the contents, clear or purulent, escaping through the lachrymal duct, to the nose, or through the puncta and accumulating in the inner canthus or flowing over the cheek. The hair beneath the inner canthus is matted together, or drops off leaving bare patches. Wolff found in one case, a distension of the sac to over two inches in breadth, and 1⅔ inches long. To the swelling there is soon added conjunctival inflammation, closure of the puncta by swelling and the escape of all tears over the face. Suppuration supervenes in the sac, and in the larger animals the pent up pus often makes its way outward, causing destructive ulceration of the walls of the canaliculi and puncta, or of the walls of the sac, the skin, or even the subjacent bone. In this way fistula results. Caries of the bone and penetration of the molar alveoli may ensue. (Girard, Leblanc).

Treatment. The first object must be to secure a free drainage into the nose. The evacuation of the sac by compression having been accomplished, an astringent solution may be injected through the nasal opening of the lachrymal duct. If the canal is pervious the sac will be re-filled and will swell out as before. The injection may be 0.5 per cent. sulphate of zinc, 1 per cent. acetate of lead, 0.3 per cent. nitrate of silver, 1 per cent. tannic acid, 2 per cent. boric acid, or 0.02 per cent. corrosive sublimate. Cocaine may be added in the proportion of 5 per cent. The injection may be repeated thrice a day at first, then twice, and finally once as the catarrh subsides.

If the injection fails to reach the sac, thoroughly sterilized, flexible probes may be used, increasing the size as they can be passed without too great pressure.

Or the puncta and canaliculi may be injected as in the human subject, the conjunctiva having been first anæsthetized by cocaine, or general ether or chloroform anæsthesia having been induced. The slitting of the puncta and canaliculi may be resorted to, as spoken of under atresia.

The frequent passage of a sound is usually resorted to, and a stilet may even be worn, but there is always danger of resulting thickening and narrowing of the duct, and, if healing can be secured without this measure, it is to be preferred.

STENOSIS OF THE LACHRYMO-NASAL DUCT.

Obliteration of the lachrymal duct may occur from stricture of the canal, the result of wounds or other irritants: from pressure by the inflamed mucosa in nasal catarrh or strangles: from polypus or osseous tumor in the nose: from actinomycosis or other disease of the bones.

The one manifest symptom is the escape of the tears on to the face. To complete the diagnosis, injection of one punctum will cause distension of the lachrymal sac.

Treatment. This may be attempted by bougies. In the horse a small sound, metallic or whalebone bougie, thoroughly sterilized and smeared with aseptic vaseline, or oil, is inserted from the nasal opening and carefully passed on into the sac. In the dog the nasal opening cannot be reached and the bougie must be passed by the puncta and lachrymal sac. To secure the requisite dilation, it is usually necessary to probe the passage daily, using a larger probe when the first passes easily, until the canal has been sufficiently dilated.