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Evaluation of the Perkins handheld applanation tonometer in horses and cattle.

Andrade SF, Kupper DS, Pinho LF, Franco EC, Prataviera MV, Duarte RR, Junqueira JR - J. Vet. Sci. (2011)

Bottom Line: IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer).In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry.Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.

View Article: PubMed Central - PubMed

Affiliation: Department of Small Animal Medicine, University of Oeste Paulista, Rodovia Raposo Tavares, km 572, CEP 19001-970, Presidente Prudente, Brazil. silviafranco@unoeste.br

ABSTRACT
The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r(2)) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 ± 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 ± 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.

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Postmortem study in an eye remaining within the orbits in the head of an adult horse. (A) A 23-gauge scalp vein needle connected via a polyethylene tube to a three-way stopcock The stopcock was also connected to a 10 mL reservoir of a 0.9% physiological saline solution with the stopcock in an open mode and to an aneroid manometer. (B) Cannulation of the anterior chamber using a 23-gauge scalp vein needle near the limbus. Cyanoacrylate glue was applied around the needle to prevent leakage of the aqueous humor.
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Figure 1: Postmortem study in an eye remaining within the orbits in the head of an adult horse. (A) A 23-gauge scalp vein needle connected via a polyethylene tube to a three-way stopcock The stopcock was also connected to a 10 mL reservoir of a 0.9% physiological saline solution with the stopcock in an open mode and to an aneroid manometer. (B) Cannulation of the anterior chamber using a 23-gauge scalp vein needle near the limbus. Cyanoacrylate glue was applied around the needle to prevent leakage of the aqueous humor.

Mentions: For the postmortem study (Fig. 1), each eye was cannulated with a 23-gauge scalp vein needle (Embramac, Brazil) through the cornea about 1 to 2 mm from the limbus in the supero-lateral quadrant. Cyanoacrylate glue (Superbond; Loctite, Brazil) was applied around the needle to prevent leakage of the aqueous humor. The needle was connected via a polyethylene tube to a three-way stopcock. The stopcock was connected to a reservoir (syringe) containing 10 mL of a physiological saline solution (Fresenius Kabi, Brazil) and to an aneroid manometer (Missouri, Brazil), which was set at the zero position relative to the center of the eye. The calibration curve for manometry versus tonometry was determined by artificially increasing the IOP in 5 mmHg increments up to 50 mmHg in tetracaine 1% the open stopcock mode. Prior to taking the tonometer reading, one drop of 1% fluorescein (Allergan, Brazil) was administered to allow for the formation of fluorescein semicircles. Three readings were taken with the Perkins tonometer (Clement Clarke, UK) and the mean value was calculated.


Evaluation of the Perkins handheld applanation tonometer in horses and cattle.

Andrade SF, Kupper DS, Pinho LF, Franco EC, Prataviera MV, Duarte RR, Junqueira JR - J. Vet. Sci. (2011)

Postmortem study in an eye remaining within the orbits in the head of an adult horse. (A) A 23-gauge scalp vein needle connected via a polyethylene tube to a three-way stopcock The stopcock was also connected to a 10 mL reservoir of a 0.9% physiological saline solution with the stopcock in an open mode and to an aneroid manometer. (B) Cannulation of the anterior chamber using a 23-gauge scalp vein needle near the limbus. Cyanoacrylate glue was applied around the needle to prevent leakage of the aqueous humor.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104172&req=5

Figure 1: Postmortem study in an eye remaining within the orbits in the head of an adult horse. (A) A 23-gauge scalp vein needle connected via a polyethylene tube to a three-way stopcock The stopcock was also connected to a 10 mL reservoir of a 0.9% physiological saline solution with the stopcock in an open mode and to an aneroid manometer. (B) Cannulation of the anterior chamber using a 23-gauge scalp vein needle near the limbus. Cyanoacrylate glue was applied around the needle to prevent leakage of the aqueous humor.
Mentions: For the postmortem study (Fig. 1), each eye was cannulated with a 23-gauge scalp vein needle (Embramac, Brazil) through the cornea about 1 to 2 mm from the limbus in the supero-lateral quadrant. Cyanoacrylate glue (Superbond; Loctite, Brazil) was applied around the needle to prevent leakage of the aqueous humor. The needle was connected via a polyethylene tube to a three-way stopcock. The stopcock was connected to a reservoir (syringe) containing 10 mL of a physiological saline solution (Fresenius Kabi, Brazil) and to an aneroid manometer (Missouri, Brazil), which was set at the zero position relative to the center of the eye. The calibration curve for manometry versus tonometry was determined by artificially increasing the IOP in 5 mmHg increments up to 50 mmHg in tetracaine 1% the open stopcock mode. Prior to taking the tonometer reading, one drop of 1% fluorescein (Allergan, Brazil) was administered to allow for the formation of fluorescein semicircles. Three readings were taken with the Perkins tonometer (Clement Clarke, UK) and the mean value was calculated.

Bottom Line: IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer).In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry.Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.

View Article: PubMed Central - PubMed

Affiliation: Department of Small Animal Medicine, University of Oeste Paulista, Rodovia Raposo Tavares, km 572, CEP 19001-970, Presidente Prudente, Brazil. silviafranco@unoeste.br

ABSTRACT
The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r(2)) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 ± 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 ± 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.

Show MeSH
Related in: MedlinePlus