|
 
- The
most common indications for corneal transplantation include pseudophakic
or aphakic bullous keratopathy; Fuchs' dystrophy, and keratoconus.
- Other
indications include corneal scar, corneal dystrophies, corneal infections,
and repeat penetrating keratoplasty for graft failure or rejection.
- Tissue
excised by the surgeon should be kept moist until the donor corneal
tissue is sewn in place and the excised tissue can be fixed or divided
for fixation and culture (where indicated).
- Formalin
fixation (10% neutral buffered formalin) is adequate for most specimens,
but keep in mind that formalin is not a universal fixative.
Formalin fixation is contraindicated in some conditions including
some types of crystalline keratopathy.
- Surgeons
are encouraged to make a quick sketch of the cornea indicating any
scars or areas of interest that would help the pathologist in examining
the tissue.
- If
orientation of the specimen is an issue, place a suture through
the specimen at one edge and indicate the clock hour of the suture's
location on the pathology requisition slip.
Top
- Cutting
corneal buttons to avoid wrinking of tissue is an art. Please contact
our laboratory staff with questions.
- The
periodic acid-Schiff (PAS) stain is performed routinely on corneal
button specimens to assist the pathologist in the visualization
of Descemet's membrane and the epithelial basement membrane.
Top
- It
is often useful to begin the histologic examination of corneal buttons
by using the PAS-stained slide to examine Descemet's membrane and
the corneal endothelium (it's where most of the action is!).
- Most
corneal buttons from patients who have had a previous penetrating
keratoplasty represent graft failure rather than immunologically-mediated
graft rejection.

Pseudophakic
bullous keratopathy, PAS stain. No endothelial cells are identified.
Pseudophakic and aphakic bullous keratopathy are leading indications
for corneal transplantation in the United States.
Top
More
Questions?
If
you have more questions about iridectomy or iridocyclectomy specimens,
please contact one of us:
Information
about another test
|