Simulated keratometry and central corneal thickness measured in cats by autokeratometer, ultrasonic pachymeter, and Galilei G6™.

OBJECTIVE: The aims of this study were to compare the central corneal thickness (CCT) measured by an ultrasonic pachymeter (SP-100, Tomey, Japão) versus the Galilei G6™ (Ziemer Ophthalmics System AG, Port, Switzerland) and to compare the simulated keratometry (SimK) measured by an autokeratometer (KM 500 Nidek) versus the Galilei G6™. ANIMAL STUDIED: Eighteen mixed-breed cats, 10 males, and eight females, aged between 18 and 48 months, were evaluated (n = 36 eyes). PROCEDURE(S): The cats were manually restrained using a blanket. The operator held the autokeratometer close to the eye and measured the SimK. Next, one anesthetic eye drop was applied; the operator lightly touched the corneal using the ultrasound pachymeter and measured the CCT. At another moment, the cats were sedated using meperidine and xylazine and then evaluated using the Galilei. Student's t-test was employed to perform the statistical analyzes. RESULTS: Considering the CCT, the ultrasound pachymeter provided mean ± SD of 623.03 ± 48.17 µm and the Galilei 617.34 ± 53.38 µm. The autokeratometer produced a SimK of 38.20 ± 0.84D (8.84 ± 0.20 mm) and the Galilei 38.37 ± 0.83D (8.80 ± 0.19 mm). The CCT and SimK did not differ statistically regardless of the device used. CONCLUSION: To the best of the authors' knowledge, this is the first work to compare the CCT measured by the Galilei versus the ultrasonic pachymeter and to compare the SimK measured by the Galilei versus the keratometer in cats. No statistical difference was found considering the CCT and the SimK measured by the different devices.

Dual-Scheimpflug-Placido-disc corneal analysis in cats.

OBJECTIVE: To evaluate the corneal topography and tomography of cats using a dual Scheimpflug and Placido disc device. ANIMAL STUDIED: Sixteen mixed-breed cats (32 eyes). PROCEDURE(S): Cats were sedated using meperidine (4.3 mg/kg/IM) and xylazine (0.5 mg/kg/IM), and evaluated using the software Galilei™. Values assessed included anterior and posterior corneal curvature, total corneal power, and corneal thickness. RESULTS: Ten males and six females aged between 18 and 48 months were evaluated. The simulated keratometry (SimK) was 38.37 ± 0.83D, mean posterior keratometry -4.89 ± 0.34D, and mean total corneal power 38.04 ± 0.94D. The mean central corneal thickness (CCT) was 617.34 ± 53.38 µm with a mean thinnest point of 583.74 ± 60.60 µm. CONCLUSION: The Galilei™ examination was feasible in cats, enabling a detailed study of the cornea. To the best of our knowledge, this is the first study evaluating the corneal topography and tomography of cats using a device that integrates data from a dual Scheimpflug and Placido disc system.