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/mm2) 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/mm2) 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.