VERMINOUS OPHTHALMIA OF THE OX.
This ophthalmia is due to the presence of a small worm, ⅔ of an inch to 1¼ inches in length, which has been regarded as the larval form of the Filaria cervina of the serous cavities.
It is very common in animals which are kept permanently in low-lying meadows particularly in some parts of France, as for instance in Normandy, in the departments of the Sarthe and the Mayenne. Not infrequently it occurs as an epizootic, and is then regarded as a contagious ophthalmia. Verminous ophthalmia occurs chiefly during the spring and autumn.
Symptoms. The disease is accompanied by lachrymation, signs of conjunctivitis, and fear of light. Very soon the media of the eye become turbid, the sclerotic and cornea are injected, and finally exhibit marked opalescence.
On examination the eye appears extremely sensitive; in fact, it can scarcely be touched unless cocaine solution is previously applied.
The parasites, two or three as a rule, but in exceptional cases from five to seven in number, are seen rolled up within the anterior chamber of the eye. A week after the beginning of the attack, however, they begin to move about, and are then found close behind the cornea, upon the lens, or suspended in the aqueous humour.
The irritation produced sets up inflammation of Descemet’s membrane and the cornea, together with iritis, and, secondly, keratitis and changes in the lens.
Unless treatment is adopted verminous ophthalmia inevitably ends in cataract.
Diagnosis. Diagnosis is always uncertain on account of the difficulty of examination. When the cornea is very opaque examination necessarily gives a negative result.
The prognosis is grave.
Treatment. Eye lotions containing tincture of aloes, creolin, corrosive sublimate, etc., have been suggested, but are practically useless, because they can have no action on a parasite enclosed within the globe of the eye. The most logical treatment consists in aseptic puncture of the anterior chamber of the eye towards its lower border with a cataract needle.
The escaping liquid carries with it the parasites, and recovery is then only a matter of time, provided the wound does not become inflamed. The great danger consists in inflammation and suppuration of the eye. This, however, can be avoided by antisepsis and by applying a surgical wool dressing, which can be left in place for a few days.