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.
The pain may be met by a solution of cocaine (1 per cent.), or atropia ½ per cent. In addition, we may irrigate with cold water or apply weak antiseptic collyria, and employ derivation by the bowels or the skin.