Comparison of Intraocular Pressure Measurement with Schiotz Tonometer and Tono-Pen Vet Tonometer in Healthy Dogs

INTRODUCTION: Measurement of intraocular pressure (IOP) in dogs has high diagnostic value because of the possibility of detecting ocular and systemic diseases. Various types of tonometers are available for this measurement in small animal practice. The aim of the study was to compare the IOP values measured with Schiotz and Tono-Pen Vet tonometers in healthy dogs. Clinical diagnostic usefulness of both models was also evaluated. MATERIAL AND METHODS: The examination was performed in 62 eyes in 31 clinically healthy dogs of different races, gender, and ages. RESULTS: The values for intraocular pressure obtained with Schiotz tonometer were in the range of 12 to 24 mmHg, with the mean of 16.3 ± 2.1 mmHg. The intraocular pressure measured with Tono-Pen Vet tonometer was in the range of 11–25 mmHg, with a mean of 18.1 ± 3.8 mmHg. The mean results of measurements taken using the two tonometers differed statistically significantly, the difference being 1.79 mmHg and the higher values being read from the Tono-Pen Vet tonometer. CONCLUSION: Correlation coefficients calculated for the results obtained in the right and left eyes using two tonometers indicated highly correlative relationships between the results. The study shows that both tonometers can be advantageously used in clinical practice to measure intraocular pressure in dogs.