Critical evaluation of the ultrasonic pachymetry for "in-vitro" corneas

Victor A. C. Lincoln; Liliane Ventura; Sidney J. Faria e Sousa

doi:10.1117/12.872885

Translator Disclaimer

11 February 2011 Critical evaluation of the ultrasonic pachymetry for "in vitro" corneas

Victor A. C. Lincoln, Liliane Ventura, Sidney J. Faria e Sousa

Author Affiliations +

Proceedings Volume 7885, Ophthalmic Technologies XXI; 78851L (2011) https://doi.org/10.1117/12.872885
Event: SPIE BiOS, 2011, San Francisco, California, United States

Abstract

The measurement of central corneal thickness (CCT) is vastly useful for diagnostic and therapeutic evaluation. The ultrasound pachymetry is currently the most common CCT technique. This study was undertaken to determine the precision and correlation of measurements obtained by mechanical and ultrasound pachymetry. The ultrasound pachymetry was determined using an A-scan ultrasonic pachymeter. The probe tip was held perpendicular on the central cornea by a support that goes down smooth to avoid excessive pressure and instability. The mechanical pachymetry was determined using a micrometer with a tip of 2mm of diameter. The tip of the micrometer was held perpendicular on the central cornea by a support that keeps stabilized. A 10x optics increase and a digital video camera shows real time image of approach and full contact of the tip with the cornea. Eight human corneas were obtained from cadaveric eyes. Measurements in both systens were taken for three different users, each one performed five readings. The results for both systems has an average SD of 33 microns refers to the systematic error between users (for positioning, center, pinching). But the difference between systems was 120 microns, possibly refers to the imprecision of ultrasound pachymetry in measuring in vitro corneas.

Citation Download Citation

Victor A. C. Lincoln, Liliane Ventura, and Sidney J. Faria e Sousa "Critical evaluation of the ultrasonic pachymetry for "in vitro" corneas", Proc. SPIE 7885, Ophthalmic Technologies XXI, 78851L (11 February 2011); https://doi.org/10.1117/12.872885

ACCESS THE FULL ARTICLE