Ultrastructural changes in corneas of diabetic patients: an electron-microscopy study.
BACKGROUND
Although diabetic retinopathy has been thoroughly studied, little attention has been given to the corneal changes of diabetic patients. Pathophysiologic and clinical findings may be related to the ultrastructural changes found in these corneas.


OBJECTIVE
To investigate the ultrastructural corneal changes of diabetic patients.


METHODS
Transmission electron microscopic ultrathin sections were prepared from corneas of 16 noninsulin-dependent diabetic patients (mean age, 65 years; range, 40-82 years) who suffered from the disease for a mean period of 22 years (range, 10-30 years). We used 16 corneas from healthy age-matched donors as normal controls.


RESULTS
In addition to the epithelial changes that include accumulation of glycogen granules, occasional focal epithelial cell degeneration, and irregular thickening and multilamination of the epithelial basement membrane, unusual 120-nm wide-spaced collagen fibril bundles were observed scattered among both Descemet's membrane and stromal matrix.


CONCLUSIONS
The aggregates of wide-spaced collagen fibrils, which have not been described in other basement membranes of diabetic patients, may reflect an excessive glycosylation rate.
Department of Ophthalmology, Western Galilee Nahariya Medical Center, Nahariya, Israel.
U
U
Rehany
Y
Y
Ishii
M
M
Lahav
S
S
Rumelt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D001485:Basement Membrane / Q000378:metabolism / Q000648:ultrastructure; D002102:Cadaver; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000378:metabolism / Q000648:ultrastructure*; D003316:Corneal Diseases / Q000378:metabolism / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000473:pathology*; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged
D006003:Glycogen; D003094:Collagen