Pathology of perforated corneal ulcer

Perforation of corneal ulcer occurs when the ulcerative process deepens and reaches up to Descemet's membrane. This membrane is tough and bulges out
as Descemetocele (Fig.1).

At this stage, any exertion on the part of patient, such as
  coughing,
sneezing, straining for stool etc. will perforate the corneal ulcer. Immediately after perforation, the aqueous escapes, intraocular pressure falls and the

       (a)        (b)

fig 1 Descemetocele : A, Diagrammatic
depiction;
B.Clinical photographs.

 

iris-lens diaphragm moves forward. The effects of perforation depend upon the position and size of perforation. When the perforation is small and
opposite to iris tissue, it is usually plugged and healing by cicatrization proceeds rapidly (Fig. 2). Adherent leucoma is the commonest end result after such a catastrophe.

Fig. 2 Perforated corneal ulcer with prolapse of iris:
A, diagrammatic depiction; B, clinical photograph.