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Journal of Current Science and Technology

ISSN 2630-0656 (Online)

Inter-instrument agreement of anterior corneal curvature measurements: Topographer, auto kerato-refractometer and manual keratometer


In this paper, inter-instrument agreement among topographer, auto kerato-refractometer and manual keratometer are the main concerns. The corneal steep, flat and average powers from the 61 right eyes of 61 healthy undergraduate students at Rangsit University were measured by three different instruments.  In statistical analysis, measurement concordance and correlation between pairs of instruments were analyzed by Bland-Altman analysis.  Intraclass correlation coefficient and paired t-test analysis were also performed.  It was found that the three instruments showed indifferent mean corneal steep and flat and average powers at a significance level of 0.05.  Therefore, topographer, auto kerato-refractometer and manual keratometer can be practically interchangeable.

Keywords: auto kerato-refractomete, Bland-Altman analysis, corneal curvature measurements, inter-instrument agreement, manual keratometer, topographer

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DOI: 10.14456/jcst.2021.14


Arce, C. G., Martiz, J., Alzamora, J. B., Schor, P., & Campos, M. S. Q. (2007). Sectorial and annular quantitative area pachymetry with the Orbscan II. Journal of refract surgery, 23, 89-92.

Bland, J. M., & Altman, D. G. (1986). Statistical methods for assessing agreement between two methods of clinical measurement. The Lancet, 327(8476), 307-310. DOI: 10.1016/S0140-6736(86)90837-8

Cantor, L. B., Rapuano, C. J., & Cioffi, G. A. (2017-2018). Basic and clinical science course (BCSC), Section 8 external disease and cornea. American Academy of Ophthalmology.

Chen, D., & Lam, A. K. (2009). Reliability and repeatability of the Pentacam on corneal curvatures. Clinical & experimental optometry 92(2): 110-118. DOI: 10.1111/j.1444-0938.2008.00336.x

Crawford, A. Z., Patel, D. V., & McGhee, C. N. (2013). Comparison and repeatability of keratometric and corneal power measurements obtained by Orbscan II, Pentacam, and Galilei corneal tomography systems. American journal of ophthalmology, 156(1), 53-60. DOI: 10.1016/j.ajo.2013.01.029

Dehnavi, Z., Khabazkhoob, M., Mirzajani, A., Jabbarvand, M., Yekta, A., & Jafarzadehpur, E. (2015). Comparison of the corneal power measurements with the TMS4-Topographer, Pentacam HR, IOL Master, and Javal Keratometer. Middle East African journal of ophthalmology, 22(2), 233-237. DOI: 10.4103/0974-9233.151884

Elbaz, U., Barkana, Y., Gerber, Y., Avni, I., & Zadok, D. (2007). Comparison of different techniques of anterior chamber depth and keratometric measurements. American journal of ophthalmology, 143(1), 48-53. DOI: 10.1016/j.ajo.2006.08.031

Grosvenor, T. (2002). Primary Care Optometry. Oxford, UK: Butterworth-Heinemann.

Gutmark, R., & Guyton, D. L. (2010). Origins of the keratometer and its evolving role in ophthalmology. Survey Ophthalmol, 55(5), 481-497. DOI: 10.1016/j.survophthal.2010.03.001.

Hidalgo, I., Rozema, J., Dhubhghaill, S., Zakaria, N., Koppen, C., & Tassignon, M. (2015). Repeatability and inter-device agreement for three different methods of keratometry: placido, scheimpflug, and color LED corneal topography. Journal of refractive surgery (Thorofare, N.J.: 1995), 31, 176-181. DOI: 10.3928/1081597X-20150224-01

Huang, J., Savini, G., Su, B., Zhu, R., Feng, Y., Lin, S., Chen, H., & Wang, Q. (2015a). Comparison of keratometry and white-to-white measurements obtained by Lenstar with those obtained by autokeratometry and corneal topography. Contact lens and anterior eye, 38(5), 363-367. DOI: 10.1016/j.clae.2015.04.003

Huang, J., Savini, G., Chen, H., Bao, F., Li, Y., Chen, H., Lu, W., Yu, Y., & Wang, Q. (2015b). Precision and agreement of corneal power measurements obtained using a new corneal topographer OphthaTOP. PLoS ONE 10(1): e109414. DOI: 10.1371/journal.pone. 0109414

Horner, D. G., Salmon, T. O., & Soni, P. S. (2006). Borish’s Clinical Refraction. Oxford, UK: Butterworth-Heinemann.

Karabatsas, C. H., Cook, S. D., Powell, K., & Sparrow, J. M. (1998). Comparison of keratometry and videokeratography after penetrating keratoplasty. Journal of refractive surgery, 14(4), 420-426. DOI: 10.3928/1081-597X-19980701-08

Koo, T. K., & Li, M. Y. (2016). A guideline of selecting and reporting intraclass correlation coefficients for reliability research. Journal of chiropractic medicine, 15(2), 155-163. DOI: 10.1016/j.jcm.2016.02.012

Magar, J. (2013). Comparison of the corneal curvatures obtained from three different keratometers. Nepalese Journal of Ophthalmology, 5(1), 9-15. DOI: 10.3126/nepjoph.v5i1.7815

Md Muziman Syah, M. M., Mutalib, H. A. , Sharanjeet Kaur, M. S., & Khairidzan Khairidzan, M. K. (2020). A Comparative Study on the Inter-Session and InterExaminer Reliability of Corneal Power Measurement Using Various Keratometry Instruments. IIUM Medical Journal Malaysia, 15(1). https://doi.org/10.31436/imjm.v15i1.409

Mehravaran, S., Asgari, S., Bigdeli, S., Shahnazi, A., & Hashemi, H. (2014), Keratometry with five different techniques: a study of device repeatability and inter-device agreement. International ophthalmology, 34, 869-875. DOI: 10.1007/s10792-013-9895-3

Razmju, H., Rezaei, L., Nasrollahi, K., Fesharaki, H., Attarzadeh, H., & Footami, F. J. (2011). IOLMaster versus manual keratometry after photorefractive keratectomy. Journal of Ophthalmic and Vision Research, 6(3), 160-165.

Shirayama, M., Wang, L., Weikert, M. P., & Koch, D. D. (2009). Comparison of corneal powers obtained from 4 different devices. American journal of ophthalmology, 148(4), 528-535.e1. DOI: 10.1016/j.ajo.2009.04.028

Wang, Q., Savini, G., Hoffer, K. J., Xu, Z., Feng, Y., Wen, D., Hua, Y., Yang, F., Pan, C., & Huang. J. (2012). A comprehensive assessment of the precision and agreement of anterior corneal power measurements obtained using 8 different devices. PLoS ONE, 7(9), e45607. DOI: 10.1371/journal.pone.0045607

Wang, X., Dong, J., & Wu, Q. (2014). Comparison of anterior corneal curvature measurements using a galilei dual scheimpflug analyzer and topcon auto kerato-refractometer. Journal of Ophthalmology, 2014: 140628. DOI: 10.1155/2014/140628

Weisenthal, R. W. (2015-2016). Basic and clinical science course (BCSC), Section 8 external disease and cornea. American Academy of Ophthalmology, 25-28.

Yu, J., Zhong, J., Mei, Z., Zhao, F., Tao, N., & Xiang, Y. (2017). Evaluation of biometry and corneal astigmatism in cataract surgery patients from Central China. BMC Ophthalmology, 17(56), (2017). DOI: 10.1186/s12886-017-0450-2

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