In large dogs, in old age, debility, conjunctival swelling, cicatrized
skin of lids, distortions of lids. Symptoms: exposure of palpebral
mucosa, weeping eyes, conjunctival hypertrophy (chemosis). Treatment:
scarify or excise a fold of mucosa, astringent antiseptics, Snellen’s
suture, Diefenbach’s operation, Wharton-Jones operation.
This is much more common than entropion, but much less injurious as the
tarsi and lashes do not irritate the conjunctiva. It is especially
common in large dogs (hounds, mastiff) and usually affects the inner
part of the lower lid. Old age and debility contribute materially to the
condition, the lack of tone or paresis being an important factor. It
may, however, occur in any animal, from conjunctivitis and swelling of
the mucosa, from cicatrices or old standing disease of the skin of the
eyelids, or from imperfectly healed wounds leaving distortions of the
lower lid. It is most frequent in the lower lid, and the slightest
pendulous condition, which detaches the tarsus from the bulb, and
exposes a narrow zone of the conjunctiva is considered to be an
ectropion.
_Symptoms._ Beside the exposure of the zone of mucosa, there is the
overflow of tears, and in old standing and bad cases a hypertrophy of
the exposed conjunctiva, which projects as a fleshy-looking mass, and
weighs down the lid, with a continual tendency to aggravation.
_Treatment._ Where the main factor seems to be the infiltration of the
mucosa this may be reduced by scarification, or by the complete excision
of a fold of the membrane. Use an antiseptic wash (boric acid) and the
retraction of healing tends to brace up the lid against the bulb.
Snellen’s suture is sometimes employed successfully. A silk thread is
armed at each end with a needle, and the needles are passed into the
conjunctiva just inside the tarsus and brought out through the skin near
the margin of the orbit, where they are tied round a small roll of
cotton. Several of these may be inserted side by side so as to extend
the whole length of the ectropion and they should be drawn tight enough
to correct the deformity. If left some days they will usually determine
cicatrices which will overcome the deformity.
The most common operation (Dieffenbach’s) is the excision of a
triangular portion of skin from just outside the lower lid and having
its base or upper side running horizontally outward from the outer
canthus. Then pare the margin of the lower lid for a distance equal to
the base of the triangle. Then bring together and suture the skin
forming the right and left sides of the triangle, and the raw edge of
the lid to the skin that formed the base of the triangle. In this way
the triangular sore formed by the operation is completely covered and
the margin of the lower lid is shortened so as to brace it up against
the bulb.
In case of cicatricial ectropion the Wharton-Jones operation is to be
adopted. A V-shaped incision is made in the skin of the lower lid
commencing just beneath the tarsus and carried down so that the two
lines of incision meet well down beneath the cicatrix. The triangular
flap of skin thus made, is detached by a bistuory from the cicatricial
tissue beneath, and allowed to shrink upward toward the tarsus. Finally
the two edges are sewed together from the angle upward, as far as may be
necessary to allow the proper application of the tarsus against the
bulb, and the remainder of these edges are sutured to those of the
triangular flap.