THE VETERINARIAN.

New Zealand Mail, Issue 849, 8 June 1888, Page 18

THE VETERINARIAN.

Ancient and Modern Veterinary Medicine. WOUNDS AND INJURIES TO THE EYE. (The Field.); Considering the very delicate structures which are included in the globe of the eye, ts exposed position, and the rough usage to which some horses are subjected, it is remarkable that comparatively lew cases of serious damage are met. Now and then a horse’s eye is utterly destroyed by a blow, and the organ shrinks into the orbit ; but in most cases no permanent harm follows from an injury which at first seems to be serious. Intense inflammation, with swelling of the eyelids and complete opacity of the cornea, and consequently loss pf.sightfora time, may result from a blow inflicted with a whip by a careless rider or driver ; but in time the swelling subsides, the cornea becomes again transparent, and no trace of the accident remains.

Injuries to the eyes may, like injuries to other organs, have remote consequences whion are not foreseen, and when detected at a later period may not be traced to the original cause. Tlius a blow on the eye may be followed by inflammation, which in the natural course will subside, aud leave no obvious signs of its'previous existence. The remote consequence of theinjurj' may be the formation of a cataract in six months’ time, when the origiual injury is not even remembered.

In regard to wounds and injuries to the eyes, the two older writers whom we have quoted repea’edly. Dr Brackeu and Gibson, evidently held views which an intervening century or more has not materially modified. They clearly recognise the possible consequence, immediate and remote, qf injuries to the eyes, and object, as the moderns do, to the old-fashioned barbarous practice, as they term it-and as we in these days also refer to it—of blowing powdered glass and other mechanical irritants into the eye for the purpose of causing the removal of opacity of the cornea, and cutting away' the cartilage nictitaus (haw) as a cure for certain defects of vision. In place of these severe and worse than useless measures, the writers advocate remedies which do not differ iu any essential charaoter from those which are now in usefomentations, local bleeding, and astringent lotions ; in fact, the favourite eye water is sulphate of zinc and rose water, a lotion which is in constant use id medical practice, and also in veterinary practice minus the rose water, which is perhaps looked upon as a refinement not required for the lower animals. In reality, it is a mild aud useful astringent,. and it is curious to note that veterinarians of the old school did not scruple to prescribe vatious confections which modern practitioners eliminate from their formulae, as too costly and unnecessarily choice for horses and cattle.

Wounds of the eyelids aie occasionally inflicted by accidental contact with a projecting nail, aud sometimes the upper or lower lid is torn away and hangs by a mere thread of connecting structure, so that the veteriuary surgeon may bo terqpted to cut it away, as the only possible method of reducing the injury to the condition of a simple wound. The practitioner who yields to this temptation regrets it, for many reasons. If the lower lid is cut away, the tears flow over the horse’s face always afterwards, and this is not a light matter. If the upper lid is damaged, a considerable blemish is the result , and there is the further very unsatisfactory reflection-that a little patience in either cas i iu adjusting the edges of the wound and stitching aud strapping tha parts together, would have prevented the unsatisfactory result. •

There is a popular belief tha” wounds of the eyelids heal with special rapidity, and it is certainly the case that a neat operator will secure the reparation of a wounded eyelid by the use of a few well-placed stitches, and thus obviate a blemish which would lessen the animal’s value, beddea subjecting it to the serious inconvenience which arises from the loss of a portion of the structures which proteot the eye from foreign bodies. Wounds may implicate the tissues of the eye itself, aud in such oases the effects are likely to be much more serious than when they are confined to the eyelids. A wound which extends through the cornea allows of the escape of the aqueous humour, aud the eye immediately becomes flattened and

shrunken, conveying the impression to the observer that the sight is lost, as indeedit is for the time ; but these apparently hopeless cases recover in a wonderful way, leaving nothing but a fine line of opacity to show where the cut was inflicted.

In some instances the injury to the cornea is followed by inflammation of the deeper structures of the eye, and various untoward consequences may be expected. Sometimes exudation is confined to the anterior chamber, which becomes filled with a yellow deposit, some of which may be afterwerds absorbed ; but a portion generally remains, causing a cloudy condition of the cornea. In other cases the exudation is more genera 1 , and the orystalline posterior part of the globe of the eye are rendered opaque, and loss or serious impairment ol vision is inevitable, even though the wound in the eye may heal up perfectly, and leave very little mark'to show where it was inflicted.

A curious, and, to the stockowner, very annoying form of opacity of the cornea, occurs among cattle and sheep in the spring and autumn. Some of the animals are seen to be suffering from irritation of the eyelids, With excessive discharge of watery, or later on mattery fluid; and on examining the eyes of the cattle or sheep by separating the lids, the cornea is found to be covered with a white cloud, as it is called, which renders the animal totally blind ; in fact, the disease is known as ‘the blinds,’ and the shepherd or herdsman, recognising the malady, suspects that a large portion of the flock or herd will suffer, and his anticipation generally proves to be correct. - . , The spreading of ‘ the blinds ’ among the animals of a flock or herd may be due to the exposure of them to the same conditions, cold and wet, which favour the development of the disease, or it may be the direct result of the infective nature of the discharge from the diseased organs. The affection, iu its chief symptoms, corresponds to ophthalinia in man, and that malady is well known to be highly contagious. Whether or not the affection has its specific microbe, which is possible, or possesses any number of septic organisms, which is most likely to be the case, the discharge would be certain to set up irritatiou if it came m contact with the mucous membrane of the eyes of a healthy animal. There is, however, something in the sudden appearance and rapid spreading of the disease which is notsoeasily explained, aud it may certainly be put in the list of the numerous affections which require much closer study than has yet been devoted to -them. Iu the treatment of disease of the outer coats of the eye, such as opacity of the cornea, the principal has been that of counterirritation—the setting up of a more severe inflammation, iu the hope, apparently, that m the new disturbance which is occasioned things may settle themselves and at last end favourably. If they do not, then a more powerful remedy is used, and more severe disturbance is caused. Some time ago, powdered glass or metal filings were blown into the eye to get rid of opacity. In the present day, mild astringent lotions, consisting of two or three grains of nitrate.of silver,.or double the quantity ofsulphate of zinc, to an ounce of water, are ÜBed with better effect, and during the treament the animal is, if possible, kept in a darkened place. This is quite out of the question m the ease of, a flock or herd, and therefore cattle and sheep suffer more severely than horses do from the disease.