Central corneal thickness measurement using ultrasonic pachymeter, optical coherence tomography, and TMS-5 topographer

• Main Authors: Kamal Hashim Binnawi, Hanaa Elzubeir, Eman Osman, Malaz Abdu, Mustafa Abdu
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2019-01-01
• Series: Oman Journal of Ophthalmology
• Subjects: Central corneal thickness; optical coherence tomography; TMS-5 topographer; ultrasonic pachymeter
• Online Access: http://www.ojoonline.org/article.asp?issn=0974-620X;year=2019;volume=12;issue=1;spage=15;epage=19;aulast=Binnawi

AIM: This study aimed to compare the central corneal thickness (CCT) measurements using Optical Coherence Tomography (OCT) and TMS-5 topographer with that taken with the gold standard digital Ultrasonic pachymeter (USP). MATERIALS AND METHODS: A total of 61 subjects (122 eyes) were prospectively and consecutively studied in a period from June 2016 to June 2017 at Sudan Eye Centre (SEC), Khartoum, Sudan. Besides the visual and refractive data, measurements of CCT were taken using OCT, TMS-5 and USP. Data analyzed using SPSS software for windows (IBM SPSS 20, IBM Corp., Armonk, NY). RESULTS: A statistically significant differences in mean CCT was detected between the three instruments (P < 0.001). USP was found to measure the CCT 29μm thicker than OCT and 22μm thicker than TMS-5 topographer. A significant difference was also found between OCT and TMS-5. OCT found to give the lower values of CCT compared to both USP and TMS-5 topographer. Further analysis showed that the three procedures were significantly and strongly correlated to each other (USP vs OCT, r = 0.77), (USP vs TMS-5, r = 0.78) and (OCT vs TMS-5, r = 0.80). CONCLUSION: Mean central corneal thicknesses (CCT) were comparable among OCT, TMS-5 topographer and the gold standard USP. However, there is a reproducible systematic difference between CCT measurements taken with the three devices. It is important to note in clinical practice, that measurements acquired by these three modalities are not directly interchangeable.