Intraocular pressure measurement in sheep using an applanation tonometer

Abstract

RESUMO Mensuração da pressão intraocular em ovinos, usando tonômetro de aplanaçãoO objetivo deste estudo foi avaliar e estabelecer os valores de pressão intraocular (PIO) média, em ovinos adultos saudáveis, usando a tonometria de aplanação. Foram utilizados no estudo 25 ovinos saudáveis (Ovis aries), da raça Texel, machos ou fêmeas de três anos de idade. Foram realizados exames oftálmicos, incluindo: avaliação dos reflexos pupilares, teste lacrimal de Schirmer, avaliação com lâmpada de fenda e coloração com fluoresceína, em ambos os olhos de todos os animais. Para a realização dos testes oftálmicos, os animais foram contidos pelo mesmo auxiliar, sem pressão na região jugular e as pálpebras foram delicadamente abertas. A PIO foi aferida, utilizando-se o tonômetro de aplanação Tonopen XL, tendo sido todos os exames realizados pelo mesmo examinador. Foram realizadas três avalia- The purpose of this study was to evaluate and establish the mean values of IOP in healthy adult sheep using an applanation tonometer. Information on age, sex, and breed was obtained for all animals included in this study. Twenty five healthy sheep (Ovis aries), of the same breed (Texel), male or female, with three years of age, received an ophthalmic examination in both eyes, including pupillary reflexes, Schirmer tear test, slit lamp biomicroscopy, and fluorescein staining. For all ophthalmic testing, animals were gently physically restrained, with no pressure in the jugular area and the eyelids were carefully open. IOP was measured by applanation tonometry (Tonopen XL). The same examiner performed the tonometry; measurements were taken three times for each eye, and their average was recorded as the IOP of the animal. Statistical analysis was performed using paired t-test and values of P < 0.05 were considered significant. The mean intraocular pressure in the whole group of 50 eyes was of 16.36 +/-2.19 mm Hg. The mean (SD) IOP in the right eye was of 15.96 +/-2.02 mm Hg, while the mean (SD) IOP in the left eye was of 16.76 +/-2.32 mm Hg. Significant differences in IOP were not found between right and left eyes. The applanation tonometer was adequate for measuring the intraocular pressure in sheep. Reference data will assist in diagnosing testing for ophthalmic disease in sheep, as 1 well as promote further studies in this area.

The eye of the Barbary sheep or aoudad (<i>Ammotragus lervia</i>): Reference values for selected ophthalmic diagnostic tests, morphologic and biometric observations

“…IOP measurements in the aoudads using the rebound tonometer resulted in means and ranges that were slightly higher than those reported for most other wild and domestic ungulates (Ofri et al, 2000(Ofri et al, , 2001Willis et al, 2000). For instance, normal reported mean IOP for sheep was 16.36 ± 2.19 mmHg (Pigatto et al, 2011), which was significantly lower (P=0.0018) than that found in the aoudad (19.47 ± 3.9 mmHg). The aoudad´s IOP seems to be similar to other ungulates with higher IOP such as the zebra (Ofri et al, 1998) and dairy cattle (Gum et al, 1998).…”

Measurement of intraocular pressure in clinically normal Turkish Shepherd Dogs with the rebound tonometer (TonoVet®) and the applanation tonometer (Tono-Pen Vet®)

“…IOP values may be high in excited, nervous and mobile dogs, especially if they are under severe stress (21). Similarly, IOP may be greatly influenced by excessive pressure exerted on the neck and eyelids during the restriction of the animal for measurement (31). The dogs used in the present study were subjected to through systemic and ophthalmologic examinations.…”

Lip twitch restraint on rebound tonometry in horses

“…Assessment intraocular pressure is crucial parameter for a complete ophthalmic exam as it contributes to the diagnosis of ocular diseases. Several methods have been described for measuring IOP in animals, including applanation, indentation, and rebound tonometry (GUM et al, 1998;KNOLLINGER et al, 2005;WANG et al, 2005 RUSANEM et al, 2010;PEREIRA et al, 2011;PIGATTO et al, 2011). In animals, both applanation and rebound tonometry are used, and correlation has been revealed between these methods (KNOLLINGER et al, 2005).…”