Bulging corneal scar with adherent iris: from perforation, escape of
aqueous, intraocular pressure, vascularization of cornea. Diagnosis by
central cicatrix, vascularisation, pigmentation. Oblique illumination.
Treatment: iridectomy, eserine. Suture. Enucleation.
This is a bulging forward of a corneal scar with the iris adherent to
its internal surface. It may originate in perforation of the cornea and
escape of the aqueous humor, or in intraocular pressure that advances
the iris until it comes in contact with the cornea, which becoming
adherent and receiving an abnormally large supply of blood or plasma,
softens and bulges outward. It may grow out to a great length in some
cases, Eck has seen it two inches in the horse, and somewhat smaller in
an ox. May records a case affecting both eyes in the dog.
_Diagnosis_ is not usually difficult. The scar in the midst of a
granulating projection of the cornea is nearly conclusive, but the
recognition of pigmentation of the growth and the adherent iris often
revealed by oblique illumination will nearly always show the true nature
of the case.
_Treatment_ is by iridectomy and eserin if the disease can be recognized
in its earliest stages, but it is rarely satisfactory. Later the choice
may be between excision of the staphyloma and coaptation of the edges of
the wound by suture, and the enucleation and removal of the eyeball. The
last resort is preferable to the continued irritation of the staphyloma
by the lids and cilia under the ocular movements.