title: Comparison of intraocular pressure measurements between the Tono-Pen XL® and Perkins® applanation tonometers in dogs and cats.
abstract: OBJECTIVE
  To compare the accuracy between two applanation tonometers, Tono-Pen XL(®) and Perkins(®), in ophthalmoscopically normal dogs and cats.
  
  
  METHODS
  Both eyes of 25 conscious and healthy dogs and cats were evaluated. Both eyes of five dogs and cats immediately after sacrifice were used as controls for the postmortem study.
  
  
  METHODS
  In conscious animals, the tonometry was performed with topical anesthesia using 0.5% proxymetacaine eye drops for both tonometers and 1% fluorescein eye drops for the Perkins tonometer. Readings of intraocular pressure (IOP) in the postmortem study were taken using manometry and tonometry by Tono-Pen XL(®) and Perkins(®).
  
  
  RESULTS
  The correlation coefficient (r(2) ) in dogs between manometry and applanation tonometers Tono-Pen XL(®) and Perkins(®) were, respectively, 0.896 and 0.981 and in cats were 0.905 and 0.988. The mean IOP values in conscious dogs with Tono-Pen XL(®) and Perkins(®) were, respectively, 17.5 ± 3.7 mmHg (10.0-25.0 mmHg) and 15.3 ± 2.1 mmHg (12.0-19.8 mmHg) and in conscious cats were 16.8 ± 3.6 mmHg (10.5-24.5 mmHg) and 15.5 ± 1.3 mmHg (13.0-18.5 mmHg).
  
  
  CONCLUSIONS
  There was a strong correlation between the IOP values obtained by direct ocular manometry and the Tono-Pen XL(®) and Perkins(®) tonometers in dogs and cats. There was no statistically significant difference between the mean IOP obtained with both tonometers in conscious animals, there was, however, a difference between the minimum and mainly in the maximum values that were on average 5-6 mmHg higher with Tono-Pen XL(®) than those measured with Perkins(®), which justifies a table of normal values differentiated for each tonometer.
authors: Department of Small Animal Medicine, Veterinary Hospital, University of Oeste Paulista (UNOESTE), Rodovia Raposo Tavares, km 572, CEP 19001-970, Presidente Prudente, SP, Brazil. silviafranco@unoeste.br
authors: Silvia Franco
authors: SF
authors: Andrade
authors: Rodrigo Jesus
authors: RJ
authors: Palozzi
authors: Rogério
authors: R
authors: Giuffrida
authors: Renata Juliane
authors: RJ
authors: de Campos
authors: Gabriela de Campos
authors: Gde C
authors: Santos
authors: Rosimery Missuzu
authors: RM
authors: Fukui
mesh_terms: D000818:Animals; D002415:Cats / Q000502:physiology*; D004285:Dogs / Q000502:physiology*; D005260:Female; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D012016:Reference Values; D014065:Tonometry, Ocular / Q000295:instrumentation / Q000662:veterinary*