Morphogeometric analysis for characterization of keratoconus considering the spatial localization and projection of apex and minimum corneal thickness point

Changes in the 3D Corneal Structure and Morphogeometric Properties in Keratoconus after Corneal Collagen Crosslinking

“…This model was then analyzed, and several morphogeometrical parameters were established. These parameters herein studied, as well as their particularities, have been previously described in several other articles [8][9][10][11][12][13][14][15]. This was also the case of several volumetric parameters related directly to the volumes around the anterior/posterior apices and the minimum thickness points [12].…”

“…Our research group developed a new method to perform a more complete morphogeometric analysis of the cornea on the basis of the data obtained from a Scheimpflug imaging-based tomography system [8]. This advanced corneal analysis has been demonstrated to be useful for characterizing the corneal structure in patients with keratoconus [9,10] for subclinical and clinical keratoconus detection [11][12][13], patient education [14], and even for characterizing the symmetry of the corneal profile between both eyes of healthy patients [15]. The aim of the current study was to conduct this 3D morphogeometric analysis to evaluate corneal changes after CXL in keratoconus patients and during a 6 month follow-up period.…”

“…A custom-made script programmed in the Matlab R2017b (Mathworks, Natick, USA) software was created to transform each point of the cloud provided by the tomographer in polar coordinates into the Cartesian format. This procedure has been meticulously described in several previous research works [8][9][10][11][12][13][14][15]. The program provides a. CSV file containing data of the points of clouds that describe both the anterior and posterior corneal surfaces for the area comprised between the geometric center of the cornea (r = 0 mm) and the mid-peripheral area (r = 4 mm).…”

“…The program provides a. CSV file containing data of the points of clouds that describe both the anterior and posterior corneal surfaces for the area comprised between the geometric center of the cornea (r = 0 mm) and the mid-peripheral area (r = 4 mm). This zone usually contains most corneal anomalies for not only diseased, but also healthy eyes [8][9][10][11][12][13][14][15]. Afterward, both surfaces were imported to the Rhinoceros V 5.0 (MCNeel and Associates, Seattle, USA) software, and the "patch" function was used to find the surfaces that better fitted the clouds of points.…”

“…• Solid modeling and morphogeometric analysis. Finally, a customized three-dimensional model of the patient's cornea was created from the surfaces previously generated in Rhinoceros by importing them to the SolidWorks V2018 (Dassault Systèmes, Vélizy-Villacoublay, France) software [8][9][10][11][12][13][14][15]. This model was then analyzed, and several morphogeometrical parameters were established.…”