Comparison of central corneal thickness measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry

• Main Authors: Hong-Tao Zhang, Hua Jiang
• Format: Article
• Language: English
• Published: Press of International Journal of Ophthalmology (IJO PRESS) 2013-09-01
• Series: Guoji Yanke Zazhi
• Subjects: central corneal thickness; Lenstar LS900; Orbscan Ⅱ; ultrasonic pachmetry; myopia
• Online Access: http://www.ies.net.cn/cn_publish/2013/9/201309018.pdf

AIM: To investigate the difference of central corneal thickness(CCT)measured by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry, and to evaluate the correlation and consistency of the results for providing a theoretical basis for clinical application.<p>METHODS: The mean value of CCT in 70 eyes of 35 patients measured three times by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry underwent statistical analysis. The difference of CCT was compared, and the correlation and consistency of three measurements were analyzed to provide theoretical basis for clinical application. CCT values measured by different methods were analyzed with randomized block variance analysis. LSD-<i>t</i> test was used for pairwise comparison between groups. The correlation of three measurement methods were analyzed by linear correlation analysis, and Bland-Altman was used to analyze the consistency.<p>RESULTS: The mean CCT values measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry were 542.75±40.06, 528.74±39.59, 538.54±40.93μm, respectively. The mean difference of CCT measurement was 4.21±8.78μm between Lenstar LS900 and ultrasonic pachmetry, 14.01±13.39μm between Lenstar LS900 and Orbscan Ⅱ, 9.8±10.57μm between ultrasonic pachmetry and Orbscan Ⅱ. The difference was statistically significant(<i>P</i><0.05). Three measurements were highly correlated(<i>P</i>>0.05): There was positive correlation between CCT with Lenstar LS900 and ultrasonic pachmetry(<i>r</i>=0.977, 0.944; <i>P</i><0.05). The analysis method of Bland-Altman: 95% consistent interval of upper and lower value was -13.0～21.4μm between Lenstar LS900 and ultrasonic pachmetry, 1.4% points outside the limits of agreement of 95%, 95% consistent interval of upper and lower value was -30.5～10.9μm between OrbscanⅡ and ultrasonic pachmetry, 7.1% points outside the limits of agreement of 95% consistent interval. <p>CONCLUSION: There are excellent correlation among Lenstar LS900, Orbscan Ⅱ and ultrasonic pachmetry. Lenstar LS900 can be used as CCT non-contact measurement tool.