The Agreement of Intraocular Pressure Measurement in Healthy Merinos Sheep Using Rebound Tonometer (Tonovet®) and Applanation Tonometer (Tono-Pen VetTM)

Sıtkıcan Okur; Latif Emrah Yanmaz; Ömer Tarık Orhun; Yakup Kocaman; Ayşe Gölgeli Bedir; Ferda Turgut; Mümin Gökhan Şenocak; Esra Modoğlu; Ugur Ersoz

doi:10.36483/vanvetj.1513839

The Agreement of Intraocular Pressure Measurement in Healthy Merinos Sheep Using Rebound Tonometer (Tonovet®) and Applanation Tonometer (Tono-Pen VetTM)

Authors : Sıtkıcan Okur, Latif Emrah Yanmaz, Ömer Tarık Orhun, Yakup Kocaman, Ayşe Gölgeli Bedir, Ferda Turgut, Mümin Gökhan Şenocak, Esra Modoğlu, Ugur Ersoz

Pages : 184-188

Doi:10.36483/vanvetj.1513839

View : 81 | Download : 30

Publication Date : 2024-11-28

Article Type : Research Paper

Abstract :The assessment of intraocular pressure (IOP) holds significant importance in ophthalmology as a crucial diagnostic tool for various ocular disorders. This study aimed to evaluate the agreement between rebound (TonoVet®, TV) and applanation (Tono-Pen Vet™, TPV) tonometers in measuring IOP in healthy Merino sheep. 155 healthy Merinos (80 males, 75 females) with a mean weight of 54.4±8.7 kg, aged 24±6 months, were included in the study. IOP was measured between 9:00 and 11:00 am using both the rebound and applanation tonometers. The rebound tonometer was used first, followed by the applanation tonometer. A total of 620 readings (310 readings for each tonometer) were obtained from the two devices. No statistical differences were noted between the mean IOP measurements of the right and left eyes for both tonometers (p>0.05). However, there was a significant difference in the mean IOP measurements between the TV (11.8±2.3 mmHg) and the TPV (13.9±2.9 mmHg) tonometers (p<0.001). The concordance correlation coefficient indicated weak agreement strength (ρc=0.319, CI 95% = -0.169 to 0.455) between the TV and TPV. The mean difference in bias and the 95% limits of agreement for the differences between TV and TPV were -2.1 mmHg (-9.0 to 3.5 mmHg). The regression equation derived from a Bland-Altman plot, describing the relationship between the two tonometers, was Y = 1.43 - 0.33X (Y = TV and X = TPV). In conclusion, the TPV measured higher IOP values compared to the TV, and due to the significant bias and limits of agreement, the two tonometers should not be used interchangeably for IOP measurement in Merino sheep.
Keywords : Aplanasyon, Intraoküler basınç, Koyun, Rebound, Tonometre

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