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.