Objective To assess the repeatability and agreement of Scheimpflug Noncontact Tonometry (Corvis ST) on normal subjects. Methods Forty-seven myopic subjects (right eye) were enrolled in this prospective study with Scheimpflug Noncontact Tonometry (Corvis ST). The right eyes of 34 myopic subjects were measured by the Ocular Response Analyser (ORA), non-contanct tonometer (NCT) and Pentacam. The repeatability of data was analyzed by intraclass correlation coefficient (ICC) and Cronbach′s Alpha coefficients, and the data were compared using a paired t test, the Pearson correlation test and Bland-Altman plot. Results The ICC and Cronbach′s Alpha coefficients of 1st A-time, 2nd A-time, Vout, HC-DA,IOPst and CCTst were more than 0.8, which showed high intraobserver repeatability. The Bland-Altman plots displayed relatively good agreement between IOPst and IOPg, IOPst and IOPcc, IOPst and IOPnct, and CCTst and CCTp. The 95% limits of agreement were -2.62 to 4.91 mmHg, -3.04 mmHg to 6.22 mmHg, -2.29 to 4.44 mmHg and -15.57 to 13.59 μm. A positive correlation was found between IOPst and IOPg, IOPst and IOPnct, and CCTst and CCTp (r=0.774, 0.791, 0.981, P<0.05). Significant differences were found between IOPst and IOPg, IOPcc, IOPnct (t=-3.464, -3.922, -3.661, P<0.05), but there was no significant difference between CCTst and CCTp (t=0.778, P>0.05). Pearson analysis showed a high correlation between 1st A-time, Vout, HC-DA and CRF, CH (r=0.721, 0.520, -0.545, -0.354, -0.596, -0.391, P<0.05). Conclusion In healthy eyes, the repeatability of some parameters using Scheimpflug Noncontact Tonometry (Corvis ST) is good. The agreement between Corvis ST and ORA and Pentacam was high.
祖培培,王雁,左彤,吴迪. 角膜生物力学眼压分析仪Corvis ST测量值的重复性与一致性研究[J]. 中华眼视光学与视觉科学杂志, 2013, 15(5): 261-265.
ZU Pei-pei,WANG Yan,ZUO Tong,WU Di. Preliminary study of the repeatability and agreement of Scheimpflug Noncontact Tonometry (Corvis ST). Chinese Journal of Optometry Ophthalmology and Visual Science, 2013, 15(5): 261-265. DOI: 10.3760/cma.j.issn.1674-845X.2013.05.002
Aghamohammadzadeh H, Newton RH, Meek KM,et al. X-ray scattering used to map the preferred collagen orientation in the human cornea and limbus. Structure,2004,12:249-256.
[2]
Shah S, Laiquzzaman M. Comparison of corneal biomechanics in pre and post-refractive surgery and keratoconic eyes by Ocular Response Analyser. Cont Lens Anterior Eye,2009,32:129-132.
[3]
Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res,1999,8:135-160.
Nam SM, Im CY, Lee HK, et al. Accuracy of RTVue optical coherence tomography, Pentacam, and ultra sound pachymetry for themeasurement of central corneal thickness. Ophthalmology,2010,117:2096-2103.
[8]
Menassa N, Kaufmann C, Goggin M, et al. Comparison and reproducibility of corneal thickness and curvature readings obtained by the Galilei and the Orbscan II analysis systems. J Cataract Refract Surg,2008,34:1742-1747.
[9]
Savini G, Barboni P, Carbonelli M, et al. Repeatability of automatic measurements by a new Scheimpflug camera combined with Placido topography. J Cataract Refract Surg,2011,37:1809-1816.
[10]
Lackner B, Schmidinger G, Pieh S, et al. Repeatability and reproducibility of central corneal thickness measurement with Pentacam, Orbscan, and ultrasound. Optom Vis Sci,2005,82:892-899.
[11]
Barkana Y, Gerber Y, Elbaz U, et al. Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low-coherence reflectometry pachymeter, and ultrasound pachymetry. J Cataract Refract Surg,2005,31:1729-1735.
[12]
O′Donnell C, Maldonado-Codina C. Agreement and repeatability of central thickness measurement in normal corneas using ultrasound pachymetry and the OCULUS Pentacam. Cornea,2005,24:920-924.
[13]
Hong J, Xu J, Wei A, et al. A new tonometer—the Corvis ST tonometer: clinical comparison with noncontact and Goldmann applanation tonometers. Invest Ophthalmol Vis Sci,2013,54:659-665.