• 1.

    Featherstone HJ, Heinrich CL. Ophthalmic examination and diagnostics, part 1: the eye examination and diagnostic procedures. In: Gelatt KN, ed. Veterinary Ophthalmology. 5th ed. John Wiley & Sons; 2013:583.

    • Search Google Scholar
    • Export Citation
  • 2.

    Brunson DB. Anesthesia in ophthalmic surgery. Vet Clin North Am Small Anim Pract. 1980;10(2):481495. doi:10.1016/s0195-5616(80)50042-2

  • 3.

    Cunningham AJ, Barry P. Intraocular pressure: physiology and implications for anaesthetic management. Can Anaesth Soc J. 1986;33(2):195208. doi:10.1007/BF03010831

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Gum GC, MacKay EO. Physiology of the Eye. In: Gelatt KN, ed. Veterinary Ophthalmology. 5th ed. John Wiley & Sons; 2013:192.

  • 5.

    Broadwater JJ, Schorling JJ, Herring IP, Elvinger F. Effect of body position on intraocular pressure in dogs without glaucoma. Am J Vet Res. 2008;69(4):527530. doi:10.2460/ajvr.69.4.527

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Klein HE, Krohne SG, Moore GR, Mohamed AS, Stiles J. Effect of eyelid manipulation and manual jugular compression on intraocular pressure measurement in dogs. J Am Vet Med Assoc. 2011;238(10):12921295. doi:10.2460/javma.238.10.1292

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Bauer BS, Ambros B. The effects of intravenous alfaxalone with and without premedication on intraocular pressure in healthy dogs. Can J Vet Res. 2016;80(2):156161.

    • Search Google Scholar
    • Export Citation
  • 8.

    Hofmeister EH, Mosunic CB, Torres BT, Ralph A, Moore PA, Read MR. Effects of ketamine, diazepam, and their combination on intraocular pressures in clinically normal dogs. Am J Vet Res. 2006;67(7):11361139. doi:10.2460/ajvr.67.7.1136

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Hofmeister EH, Weinstein WL, Burger D, Brainard BM, Accola PJ, Moore PA. Effects of graded doses of propofol for anesthesia induction on cardiovascular parameters and intraocular pressures in normal dogs. Vet Anaesth Analg. 2009;36(5):442448. doi:10.1111/j.1467-2995.2009.00482.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Hofmeister EH, Williams CO, Braun C, Moore PA. Influence of lidocaine and diazepam on peri-induction intraocular pressures in dogs anesthetized with propofol-atracurium. Can J Vet Res. 2006;70(4):251256.

    • Search Google Scholar
    • Export Citation
  • 11.

    Hofmeister EH, Williams CO, Braun C, Moore PA. Propofol versus thiopental: effects on peri-induction intraocular pressures in normal dogs. Vet Anaesth Analg. 2008;35(4):275281. doi:10.1111/j.1467-2995.2007.00385.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Bhartiya S, Bali SJ, James M, Panda A, Dada T. Test retest variability of TonoPen AVIA. Indian J Ophthalmol. 2013;61(3):129131. doi:10.4103/0301-4738.109384

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Stamper RL. A history of intraocular pressure and its measurement. Optom Vis Sci. 2011;88(1):E16E28. doi:10.1097/OPX.0b013e318205a4e7

  • 14.

    Kahane N, Bdolah-Abram T, Raskansky H, Ofri R. The effects of 1% prednisolone acetate on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost. Vet Ophthalmol. 2016;19(6):473479. doi:10.1111/vop.12329

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Kahane N, Raskansky H, Bdolah-Abram T, Ofri R. The effects of topical parasympatholytic drugs on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost. Vet Ophthalmol. 2016;19(6):464472. doi:10.1111/vop.12330

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Costa D, Leiva M, Coyo N, Laguna F, Rios J, Gimenez MTP. Effect of topical 1% cyclopentolate hydrochloride on tear production, pupil size, and intraocular pressure in healthy Beagles. Vet Ophthalmol. 2016;19(6):449453. doi:10.1111/vop.12323

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Espinheira Gomes F, Brandão J, Sumner J, et al. Survey of ophthalmic anterior segment findings and intraocular pressure in 95 North American box turtles (Terrapene spp.). Vet Ophthalmol. 2016;19(2):93101. doi:10.1111/vop.12257

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    McDonald JE, Kiland JA, Kaufman PL, Bentley E, Ellinwood NM, McLellan GJ. Effect of topical latanoprost 0.005% on intraocular pressure and pupil diameter in normal and glaucomatous cats. Vet Ophthalmol. 2016;19 (Suppl 1):1323. doi:10.1111/vop.12292

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Gosling AA, Kiland JA, Rutkowski LE, Hoefs A, Ellinwood NM, McLellan GJ. Effects of topical corticosteroid administration on intraocular pressure in normal and glaucomatous cats. Vet Ophthalmol. 2016;19 (Suppl 1):6976. doi:10.1111/vop.12355

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 20.

    Kiland JA, Voss AM, McLellan GJ. Effect of timolol maleate gel-forming solution on intraocular pressure, pupil diameter, and heart rate in normal and glaucomatous cats. Vet Ophthalmol. 2016;19(Suppl 1):9196. doi:10.1111/vop.12376

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Sanchez RF, Vieira da Silva MJ, Dawson C. Design of an intraocular pressure curve protocol for use in dogs. J Small Anim Pract. 2017;58(1):4248. doi:10.1111/jsap.12600

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Pauli AM, Bentley E, Diehl KA, Miller PE. Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs. J Am Anim Hosp Assoc. 2006;42(3):207211. doi:10.5326/0420207

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23.

    Gaton DD, Ehrenberg M, Lusky M, et al. Effect of repeated applanation tonometry on the accuracy of intraocular pressure measurements. Curr Eye Res. 2010;35(6):475479. doi:10.3109/02713681003678824

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    AlMubrad TM, Ogbuehi KC. The effect of repeated applanation on subsequent IOP measurements. Clin Exp Optom. 2008;91(6):524529. doi:10.1111/j.1444-0938.2008.00298.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Stewart WC, Geiger AC, Jenkins JN. The benefit of repeated intraocular pressure measurements in clinical trials. Arch Ophthalmol. 2004;122(6):936937. doi:10.1001/archopht.122.6.936-b

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Stewart WC, Stewart JA, Nelson LA. Glaucoma clinical trial design: a review of the literature. Perspect Clin Res. 2014;5(3):108114. doi:10.4103/2229-3485.134306

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    Pahlitzsch M, Brünner J, Gonnermann J, et al. Comparison of ICare and IOPen vs Goldmann applanation tonometry according to international standards 8612 in glaucoma patients. Int J Ophthalmol. 2016;9(11):16241628. doi:10.18240/ijo.2016.11.14

    • Search Google Scholar
    • Export Citation
  • 28.

    Yoo Y-C, Kim NY, Shin S, et al. The intraocular pressure under deep versus moderate neuromuscular blockade during low-pressure robot assisted laparoscopic radical prostatectomy in a randomized trial. PLoS One. 2015;10(8):e0135412 doi:10.1371/journal.pone.0135412

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 29.

    Karaman T, Dogru S, Karaman S, et al. Intraocular pressure changes: the McGrath video laryngoscope vs the Macintosh laryngoscope; a randomized trial. J Clin Anesth. 2016;34:358364.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 30.

    Dielemans I, Vingerling JR, Hofman A, Grobbee DE, de Jong PT. Reliability of intraocular pressure measurement with the Goldmann applanation tonometer in epidemiological studies. Graefes Arch Clin Exp Ophthalmol. 1994;232(3):141144. doi:10.1007/BF00176782

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 31.

    Kass MA. Standardizing the measurement of intraocular pressure for clinical research: guidelines from the Eye Care Technology Forum. Ophthalmology. 1996;103(1):183185. doi:10.1016/s0161-6420(96)30741-0

    • Crossref
    • Search Google Scholar
    • Export Citation

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Single instead of triplicate intraocular pressure measurements in dogs do not substantially lower accuracy and precision but do slightly reduce statistical power

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  • 1 Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA

Abstract

OBJECTIVE

To compare single and triplicate applanation tonometry values across previous intraocular pressure (IOP) studies in dogs.

ANIMALS

116 ophthalmologically normal dogs.

PROCEDURES

Triplicate IOP readings (n = 1432) from studies evaluating effect of anesthetic protocols were analyzed to estimate a range of probable differences between averaged triplicate and first, averaged and lowest, and first and lowest IOPs. The decrease in variability with triplicate measurements and the magnitude of effects on statistical power were quantified.

RESULTS

The 2.5th to 97.5th interpercentile range for differences of averaged triplicate values minus first IOP readings was –3 to 2.7 mm Hg; for averaged minus lowest: 0 to 3.7 mm Hg; for first minus lowest: 0 to 5 mm Hg. The 95% prediction interval for differences in study group means (n = 160 groups, n = 5 to 11 eyes per group) based on averaged minus first measurements was –1.0 to 0.9 mm Hg with associated SDs reduced by 4% on average. Analysis of previous studies using averaged instead of first IOP values resulted in minimal decreases in SEs of 3–9% (0.03 to 0.09 mm Hg). Of 11 comparisons found significant with averaged data, 2 (18%) were found nonsignificant with first measurements. Of 96 comparisons found nonsignificant with averaged data, 3 (3%) were found significant with first measurements.

CLINICAL RELEVANCE

With applanation tonometry in ophthalmologically normal dogs, no clinically meaningful difference was found between the first, lowest, or averaged triplicate IOP measurements, but the first reading has a larger variance and hence will result in lower statistical power.

Supplementary Materials

    • Supplementary Table S1 (PDF 100 KB)
    • Supplementary Table S2 (PDF 93 KB)
    • Supplementary Table S3 (PDF 95 KB)
    • Supplementary Table S4 (PDF 88 KB)

Contributor Notes

Corresponding author: Dr. Hofmeister (kaastel@gmail.com)