Corneal sensitivity in dogs with diabetes mellitus.
OBJECTIVE
To compare aesthesiometer-determined corneal sensitivity between diabetic and nondiabetic dogs and to investigate the correlation between corneal sensitivity and duration of diabetes or status of glycemic control, as estimated by use of glycated blood protein concentrations.


METHODS
23 diabetic and 29 nondiabetic normoglycemic dogs.


METHODS
A Cochet-Bonnet aesthesiometer was used to measure corneal touch threshold (CTT) in 5 corneal regions of each dog. At the time of ocular examination, duration of diabetes mellitus was estimated from the history, and blood was drawn for assessment of blood glycosylated hemoglobin and serum fructosamine concentrations.


RESULTS
Median CTT for central, nasal, dorsal, temporal, and ventral corneal regions in nondiabetic dogs (1.6, 2.3, 2.8, 2.8, and 5.1 g/mm2, respectively) was significantly lower than in diabetic dogs (2.8, 4.0, 5.1, 5.1, and 6.6 g/mm2, respectively). Median regional CTT in diabetic dogs was not significantly correlated with estimated duration of diabetes mellitus or blood glycated protein concentrations. No significant difference was found in regional CTT between eyes of normoglycemic dogs with unilateral cataracts.


CONCLUSIONS
Diabetic dogs have significantly reduced corneal sensitivity in all regions, compared with nondiabetic normoglycemic dogs. Regional variation in corneal sensitivity is similar in diabetic and normoglycemic dogs. Neither glycemic control nor duration of diabetes, as estimated, is significantly correlated with corneal hyposensitivity. Corneal nerve dysfunction may be associated with recurrent or nonhealing ulcers in diabetic dogs for which no other underlying cause can be found.
Good
Kathryn L
KL
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Maggs
David J
DJ
Hollingsworth
Steven R
SR
Scagliotti
Randall H
RH
Nelson
Richard W
RW
D000818:Animals; D003315:Cornea / Q000502:physiology / Q000503:physiopathology*; D003316:Corneal Diseases / Q000150:complications / Q000503:physiopathology / Q000662:veterinary*; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000503:physiopathology / Q000662:veterinary*; D003928:Diabetic Nephropathies / Q000503:physiopathology / Q000662:veterinary; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D019270:Fructosamine / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis; D008297:Male; D018709:Statistics, Nonparametric; D014110:Touch / Q000502:physiology
D019270:Fructosamine; D006442:Glycated Hemoglobin