Objectives

To compare systolic blood pressure (SBP) and ophthalmic examination findings including blink rate, corneal sensitivity, Schirmer tear test (STT), intraocular pressure (IOP), tear film break up time (TFBUT), tear film glucose and conjunctival microflora between cats with spontaneously-occurring diabetes mellitus and age-matched non-diabetic cats.

Methods

Twenty-one cats in each group underwent clinical, neurological and ophthalmic examination, including SBP measurement, assessment of blink rate, corneal touch threshold (CTT), STT, applanation tonometry, TFBUT, tear glucose and prolonged aerobic bacterial culture of the conjunctival sac.

Results

Corneal sensitivity was found to be significantly lower in the diabetic group compared with the non-diabetic group using both a Cochet-Bonnet aesthesiometer and a non-contact corneal aesthesiometer (p<0.0001). There was a significant statistical difference in the intraocular pressures among the diabetic (mean 14.90mmHg) and the non-diabetic (mean 12.79mmHg) groups (p=0.031).

TFBUT was significantly more rapid (p=0.01) in the diabetic group, with a mean of 11.42 seconds, when compared with the non-diabetic group, with a mean of 15.02 seconds. Tear film glucose levels were significantly higher (p<0.001) in the diabetic group than in the non-diabetic group.

No statistically significant difference was found in SBP, blink rate, STT, and conjunctival microflora between the groups.

Clinical Significance

Corneal sensitivity was significantly lower in diabetic cats which may lead to delayed corneal healing and a predisposition for corneal ulcer formation. TFBUT was significantly lower among diabetic cats, and qualitative tear film deficiency could lead to premature evaporation of the tear film and further confound corneal healing. Cats with spontaneously-occurring diabetes mellitus were found to be no more likely to be hypertensive than an age-matched population of cats.

This project was funded by Petsavers.