Definition. Dog, anatomical factors. Symptoms: protrusion of bulb
through palpebral orifice, orbicular spasm, vessel, muscle, nerve
stretching or tearing. Sphacelus. Panophthalmia. Fracture of orbit.
Treatment: early reduction, antisepsis, astringents, scarify sclera,
cold, astringents, puncture aqueous with hypodermic needle, enlarge
palpebral opening, suture and compress, remove foreign bodies and
injurious fragments of tissues, enucleation.
_Definition._ Displacement of the globe of the eye out of the orbit and
through the eyelids.
_Causes._ Among domestic animals the condition is most frequently seen
in the dog, which is predisposed by reason of the normal prominence of
its eye, the width of the aperture between the lids and the absence of
the orbital process of the frontal bone. Blows upon the region and the
insertion of pointed bodies, (teeth, horns, etc.), which can act as
levers using the margin of the orbit as a fulcrum are especially liable
to cause the lesion. Dog fights are the most common occasions. Other
animals may also suffer but not at all frequently.
_Symptoms and lesions._ In the simplest form the bulb is displaced
forward out of the orbit and through the palpebræ which latter contract
spasmodically behind it and effectually prevent a spontaneous reduction.
The optic nerve, muscles, and vessels are unduly stretched and the
circulation in the bulb is seriously impaired, so that even in the least
complicated cases any undue delay in reducing the dislocation will lead
to serious and destructive changes in the eye. Sphacelus of the globe is
not uncommon under such conditions.
In the more complicated cases, the conjunctiva, palpebræ, nictitans,
muscles, nerves, etc., maybe more or less lacerated and the globe itself
may be seriously damaged either by internal lesion or by an external
trauma. In all these cases there is most imminent danger of general
infective inflammation of the eye, of panophthalmia, and even of
secondary general infection of the system. Fracture of the bones of the
orbit may also be looked for.
_Treatment._ When dislocation is uncomplicated and recent, say of a few
hours standing only, it may be reduced and a favorable issue secured.
The bulb should be first washed with water which has been sterilized by
boiling or rendered antiseptic with sublimate (1 ∶ 5000), and can
usually be pressed back by steady uniform pressure. The insertion under
one lid of a small spatula bent at the end or the one limb of a lid
speculum may assist in difficult cases. When replaced the parts may be
again washed with antiseptic solution and covered by a bandage wet with
an astringent collyria.
When the condition has been neglected for a day or more the bulb is
congested and swollen so that its return is rendered much more
difficult, and its subsequent retention may require much care and
ingenuity. The reduction of the turgid globe may be assisted by opening
the veins and arteries on the sclera, by astringent applications, by
massage, and in obstinate cases by evacuation of a portion of the
aqueous humor, by the aid of a fine aseptic needle. Finally the
palpebral opening may be enlarged by incising the outer canthus with a
probe pointed bistuory. When the eye has been replaced in its socket
this must be closed by suture. For the retention of the eye in such
cases a bandage may suffice, or this failing, the lids may be held
together by strips of adhesive plaster, or by collodion. In very
difficult cases Lafosse and Trasbot recommend sutures through the skin
1½ to 2 inches from the palpebral borders and the whole covered with a
bandage impregnated with an antiseptic and astringent collyrium.
It is not requisite to keep the bandage in position for over four or
five days as the swelling of the eyelids and other adjacent structures
effectually prevents any tendency to repetition of the luxation, and the
eye may be treated like an ordinary traumatic lesion.
At the outset, and later if need be, any foreign body in the orbit
should be removed and any detached pieces of bone which cannot be
retained firmly in position, and which are liable to prevent healing or
to determine infection of the wound.
In the worst cases and in those that have been neglected until gangrene
or panophthalmitis threatens, the removal of the eyeball may be the only
resort. The animal may be anæsthetized by chloroform or ether, or
locally by cocaine. The conjunctiva covering the sclera is then pinched
up with forceps and cut through with scissors, this is continued all
around the globe. Then the recti muscles, the superior and inferior
oblique muscles, the retractor and finally the optic nerve are cut
through with a pair of scissors curved on the flat. The divided ends of
the muscles are now sutured together around the nerve which has been cut
shorter, and the cavity irrigated by a cold antiseptic solution.
Bleeding vessels may be twisted through with forceps if the flow is not
readily checked by cold irrigation. Or a pledget of cotton dipped in
tincture of muriate of iron may be loosely inserted (firm pressure would
be unnecessarily painful). As a subsequent dressing, standard sulphurous
acid solution, glycerine and water in equal proportions, or other
antiseptic dressings may be applied.