Open Access
20 May 2015 Correction on the distortion of Scheimpflug imaging for dynamic central corneal thickness
Tianjie Li, Lei Tian, Like Wang, Ying Hon, Andrew K. C. Lam, Yifei Huang, Yuanyuan Wang, Yongping Zheng
Author Affiliations +
Abstract
The measurement of central corneal thickness (CCT) is important in ophthalmology. Most studies concerned the value at normal status, while rare ones focused on its dynamic changing. The commercial Corvis ST is the only commercial device currently available to visualize the two-dimensional image of dynamic corneal profiles during an air puff indentation. However, the directly observed CCT involves the Scheimpflug distortion, thus misleading the clinical diagnosis. This study aimed to correct the distortion for better measuring the dynamic CCTs. The optical path was first derived to consider the influence of factors on the use of Covis ST. A correction method was then proposed to estimate the CCT at any time during air puff indentation. Simulation results demonstrated the feasibility of the intuitive-feasible calibration for measuring the stationary CCT and indicated the necessity of correction when air puffed. Experiments on three contact lenses and four human corneas verified the prediction that the CCT would be underestimated when the improper calibration was conducted for air and overestimated when it was conducted on contact lenses made of polymethylmethacrylate. Using the proposed method, the CCT was finally observed to increase by 66±34  μm at highest concavity in 48 normal human corneas.
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Tianjie Li, Lei Tian, Like Wang, Ying Hon, Andrew K. C. Lam, Yifei Huang, Yuanyuan Wang, and Yongping Zheng "Correction on the distortion of Scheimpflug imaging for dynamic central corneal thickness," Journal of Biomedical Optics 20(5), 056006 (20 May 2015). https://doi.org/10.1117/1.JBO.20.5.056006
Published: 20 May 2015
Lens.org Logo
CITATIONS
Cited by 16 scholarly publications.
Advertisement
Advertisement
KEYWORDS
Cornea

Calibration

Distortion

Cameras

Refractive index

Distance measurement

Eye

Back to Top