Corneal sensitivity in healthy, immature, and adult alpacas.

Abstract

OBJECTIVE:   To determine the corneal sensitivity of healthy, immature, and adult alpacas to establish normal reference values for this species. ANIMALS STUDIED:   Six normal crias and 18 normal adult alpacas. PROCEDURES:   Corneal sensitivity was determined by evaluating the corneal touch threshold (CTT) in five regions of the cornea using a Cochet-Bonnet aesthesiometer. The nylon filament length in cm was then converted to applied pressure values in mg/0.0113 mm(2) and g/mm(2) using a conversion chart. RESULTS:   The central region of the cornea was the most sensitive, and the dorsal and temporal regions were the least sensitive in alpacas. There were no significant differences between the right and left eyes or between values in males and females at any site. Crias had significantly greater corneal sensitivity compared with adult alpacas in all five regions of the cornea that were evaluated. CONCLUSIONS:   Normal reference values for CTT in alpacas were established using a Cochet-Bonnet aesthesiometer. The central region of the cornea is the most sensitive in alpacas, and crias have higher corneal sensitivity than adult alpacas.