Abstract
Purpose
To determine the effects of central corneal thickness (CCT), central corneal power (CCP), and axial length (AL) on the measurement of intraocular pressure (IOP) using Goldmann applanation tonometry, and the effects of CCP and AL on CCT.
Methods
Charts of 147 consecutive patients undergoing preoperative examinations for cataract surgery between April 2006 and April 2007 in our clinic were reviewed retrospectively. CCT, CCP, and AL were measured by ultrasonic pachymeter (Micropach Model 200P, Sonomed, Lake Success, N.Y. USA), autorefractokeratometer (KR 8800, Topcon, Tokyo, Japan), and ultrasound biometry (EZ Scan AB 5500+ Sonomed, Lake Success, N.Y. USA). Pearson correlation analysis and multiple linear regression analysis were used as indicated, and only one eye of each subject was included in the statistical analysis.
Results
Ninety-eight eyes of 98 patients were included in the study. IOP and CCT were significantly and positively correlated (P < 0.001), and CCT and CCP (P = 0.001) were inversely correlated. Multiple regression analysis showed that the effect of CCT on IOP was statistically significant (P < 0.001), but the effects of CCP and AL on IOP were not significant (P = 0.614, P = 0.831, respectively). IOP increased by 0.29 mmHg for each 10 µm increase in CCT.
Conclusions
CCT, but not CCP or AL, significantly affected IOP readings obtained by Goldmann applanation tonometry. The effect of CCP on IOP was weak and not significant despite the significant inverse correlation between CCT and CCP.
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References
Doughty MJ, Zaman ML. Human corneal thickness and its impact on intraocular pressure measures: a review and meta-analysis approach. Surv Ophthalmol 2000;44:367–408.
Goldmann H, Schmidt T. Applanation tonometry. Ophthalmologica 1957;134:221–242.
Ehlers N, Bramsen T, Sperling S. Applanation tonometry and central corneal thickness. Acta Ophthalmol (Copenh) 1975;53:34–43.
Wolfs RC, Klaver CC, Vingerling JR, Grobbee DE, Hofman A, de Jong PT. Distribution of central corneal thickness and its association with intraocular pressure: The Rotterdam Study. Am J Ophthalmol 1997;123:767–772.
Paranhos A, Paranhos FR, Prata JA, Omi CA, Mello PA, Shields MB. Influence of keratometric readings on comparative intraocular pressure measurements with Goldmann, Tono-Pen, and noncontact tonometers. J Glaucoma 2000;9:219–223.
Brandt JD, Beiser JA, Kass MA, Gordon MO. Central corneal thickness in the Ocular Hypertension Treatment Study (OHTS). Ophthalmology 2001;108:1779–1788.
Bhan A, Browning AC, Shah S, Hamilton R, Dave D, Dua HS. Effect of corneal thickness on intraocular pressure measurements with the pneumotonometer, Goldmann applanation tonometer, and Tono-Pen. Invest Ophthalmol Vis Sci 2002;43:1389–1392.
Eysteinsson T, Jonasson F, Sasaki H, et al.; Reykjavik Eye Study Group. Central corneal thickness, radius of the corneal curvature and intraocular pressure in normal subjects using non-contact techniques: Reykjavik Eye Study. Acta Ophthalmol Scand 2002;80:11–15.
Viestenz A, Wakili N, Junemann AG, Horn FK, Mardin CY. Comparison between central corneal thickness and IOP in patients with macrodiscs with physiologic macrocup and normal-sized vital discs. Graefes Arch Clin Exp Ophthalmol 2003;241:652–655.
Shimmyo M, Ross AJ, Moy A, Mostafavi R. Intraocular pressure, Goldmann applanation tension, corneal thickness, and corneal curvature in Caucasians, Asians, Hispanics, and African Americans. Am J Ophthalmol 2003;136:603–613.
Tong L, Saw SM, Siak JK, Gazzard G, Tan D. Corneal thickness determination and correlates in Singaporean schoolchildren. Invest Ophthalmol Vis Sci 2004;45:4004–4009.
Gunvant P, Baskaran M, Vijaya L, Joseph IS, Watkins RJ, Nallapothula M, et al. Effect of corneal parameters on measurements using the pulsatile ocular blood flow tonograph and Goldmann applanation tonometer. Br J Ophthalmol 2004;88:518–522.
Gunvant P, O’Leary DJ, Baskaran M, Broadway DC, Watkins RJ, Vijaya L. Evaluation of tonometric correction factors. J Glaucoma 2005;14:337–343.
Saleh TA, Adams M, McDermott B, Claridge KG, Ewings P. Effects of central corneal thickness and corneal curvature on the intraocular pressure measurement by Goldmann applanation tonometer and ocular blood flow pneumatonometer. Clin Experiment Ophthalmol 2006;34:516–520.
Kohlhaas M, Boehm AG, Spoerl E, Pursten A, Grein HJ, Pillunat LE. Effect of central corneal thickness, corneal curvature, and axial length on applanation tonometry. Arch Ophthalmol 2006;124:471–476.
Gordon MO, Beiser JA, Brandt JD, et al. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol 2002;120:714–720.
Mark HH. Corneal curvature in applanation tonometry. Am J Ophthalmol 1973;74:223–224.
Touzeau O, Allouch C, Borderie V, Kopito R, Laroche L. Correlation between refraction and ocular biometry. J Fr Ophtalmol 2003;26:355–363.
Shimmyo M, Orloff PN. Corneal thickness and axial length. Am J Ophthalmol 2005;139:553–554.
Orssengo GJ, Pye DC. Determination of the true intraocular pressure and modulus of elasticity of the human cornea in vivo. Bull Math Biol 1999;61:551–572.
Mitchell P, Hourihan F, Sandbach J, Wang JJ. The relationship between glaucoma and myopia: the Blue Mountains Eye Study. Ophthalmology 1999;106:2010–2015.
Lotufo D, Ritch R, Szmyd L Jr, Burris JE. Juvenile glaucoma, race, and refraction. JAMA 1989;261:249–252.
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Özcura, F., Aydın, S. & Uzgören, N. Effects of central corneal thickness, central corneal power, and axial length on intraocular pressure measurement assessed with goldmann applanation tonometry. Jpn J Ophthalmol 52, 353–356 (2008). https://doi.org/10.1007/s10384-008-0535-9
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DOI: https://doi.org/10.1007/s10384-008-0535-9