Corneal Properties of Keratoconus Based on Scheimpflug Light Intensity Distribution
Investigative Ophthalmology & Visual Science 2019 | Vol.60, 3197-3203
Alejandra Consejo; Karolina Gławdecka; Karol Karnowski; Jędrzej Solarski; Jos J. Rozema; Maciej Wojtkowski; D. Robert Iskander
Purpose: We introduce a new approach to assess the properties of corneal microstructure in vivo of healthy control and keratoconus eyes, based on statistical modeling of light intensity distribution from Scheimpflug images.
Methods: Twenty participants (10 mild keratoconus and 10 control eyes) were included in this study. Corneal biomechanics was assessed with a commercial Scheimpflug camera technology. Sets of 140 images acquired per measurement were exported for further analysis. For each image, after corneal segmentation, the stromal pixel intensities were statistically modeled, leading to parametric time-series that characterizes distributional changes during the measurement. From those time series, a set of 10 newly introduced parameters (microscopic parameters) was derived to discriminate normal from keratoconic corneas and further compared against clinical parameters available from the same measuring device, including central corneal thickness, IOP, and deformation amplitude (macroscopic parameters).
Figure Legend: Corneal Scheimpflug images and the ROI (yellow lines) selected for analysis for a randomly chosen participant. (A) The shape of the cornea prior before the air-puff; (B) the shape of the cornea at the highest concavity. On the right is the corresponding histogram of pixel intensities in each ROI without normalization.