Functional measurements on the enlarged endothelial cells of corneal transplants.
OBJECTIVE
To measure the morphologic and functional status of the endothelium of long-term corneal transplants.


METHODS
We induced hypoxic corneal edema and measured corneal deswelling (expressed as percent recovery per hour, PRPH, over 7 hours) with a modified optical pachometer in 12 corneas of 8 patients transplanted 7-18 years previously and in 21 normal adult control subjects. Fluorophotometry and specular microscopy were also performed on each eye. Results in the 2 groups were compared with a 2-tailed Student T test for means.


RESULTS
The transplanted corneas had significantly decreased PRPH, induced swelling, endothelial permeability to fluorescein, and endothelial cell density compared to the controls, despite a similar estimated open-eye steady-state thickness.


CONCLUSIONS
The markedly enlarged endothelial cells of long-term corneal transplants have a reduced ability to deturgesce the cornea and decreased permeability to small solutes. These findings could result from a reduction in intercellular space that occurs when the number of cells lining the posterior surface of the cornea is substantially decreased.
Bourne
W M
WM
Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D002463:Cell Membrane Permeability; D015715:Corneal Edema / Q000503:physiopathology; D004728:Endothelium, Corneal / Q000473:pathology / Q000503:physiopathology*; D015590:Fluorophotometry; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology; D015948:Keratoplasty, Penetrating / Q000502:physiology; D008875:Middle Aged