Abstract

Corneal sensitivity and the duration of action of a topical anesthetic drop, proparacaine, were evaluated prospectively. Baseline corneal touch threshold (CTT) was determined using a Cochet-Bonnet esthesiometer in 25 healthy, rehabilitated Kemp's ridley sea turtles (Lepidochelys kempii). Corneal touch threshold was defined as the filament length required to elicit a blink in at least three out of five applications. The onset and duration of action of proparacaine was determined in nine of the Kemp's ridley sea turtles. One drop of proparacaine was applied to each eye and the CTT was subsequently measured at 1, 5, 15, 30, and 45 min. Results demonstrated that the mean CTT for the Kemp's ridley sea turtles was 5.7 cm, with a median of 6 cm. Additionally, proparacaine had an onset of action within 1 min after application (17/18 eyes). The duration of action of proparacaine exceeded the 45 min time limit in all eyes. This study shows that Kemp's ridley sea turtles have an exceptionally sensitive cornea. This study also establishes that proparacaine, a topical anesthetic, is effective in Kemp's ridley sea turtles, with an onset of action within 1 min and a duration of action greater than 45 min following application.