A comparison of corneal sensitivity between brachycephalic and Domestic Short-haired cats

Objective To compare sensitivity of the central and peripheral cornea of brachycephalic and Domestic Short-haired (DSH) cats. Design Prospective study. Animals Fifty DSH, thirteen Persian, and seven Himalayan cats. Criteria for inclusion Healthy DSH, Persian, or Himalayan cats older than 6 months, with a normal ophthalmic examination and Sno-strip values greater than or equal to 5 mm wetting/60 s. Materials and methods Corneal sensitivity was measured using a Cochet-Bonnet aesthesiometer. The cornea was touched using the tip of the monofilament, decreasing the fiber length in 5 mm increments until a blink reflex occurred. Corneal touch threshold was defined as the stimulus that elicited a corneal blink reflex greater than 50% of the time. Results Mean central and peripheral corneal touch threshold (CTT +/- SD in gm/mm(2)) for the DSH cats were 1.79 +/- 2.33 and 5.01 +/- 5.07 in the right eye (OD), and 1.74 +/- 1.65 and 5.02 +/- 4.55 in the left eye (OS). Mean central and peripheral CTT +/- SD (gm/mm(2)) for the brachycephalic cats were 4.09 +/- 5.29 and 6.18 +/- 5.65 OD, and 3.18 +/- 3.75 and 7.66 +/- 6.24 OS. Statistical analysis of the data revealed a significantly higher CTT in the central (P = 0.019) and peripheral (P = 0.003) cornea of brachycephalic than DSH cats. When evaluated for gender, this difference persisted in female cats, but did not hold true for male cats. A significant difference in CTT was found between central and peripheral cornea within both groups of cats. Conclusions The central cornea is less sensitive in brachycephalic than DSH cats. The central cornea is more sensitive than the peripheral cornea in both brachycephalic and DSH cats.