Corneal Indices Determined with Pentacam in Possible Candidates for Corneal Refractive Surgery

Eduardo Rojas Alvarez1, *, Giuseppe Miotto Montesinos2, Diego Manolo Torres Piedra2, Nataly Torres Palacios4, Osvaldo Fosado Téllez3
1 University of Cuenca. Exilaser Ophthalmological Center, Cuenca, Ecuador
2 Exilaser Ophthalmological Center, Cuenca, Ecuador
3 Technical University of Manabi. Ecuador
4 Postgraduate Institute. Technical University of Manabi



To describe the level of correlation of clinical refractive variables with corneal indices in Pentacam Scheimpflug tomography, demonstrate the usefulness of the study of corneal indices in the diagnosis of keratoconus (KC), and identify the corneal indexes with the greatest influence on the diagnosis of KC.


A descriptive, retrospective, and cross-sectional study was conducted in 69 patients (138 eyes) with refractive disorders, possible candidates for corneal refractive surgery, at the Exilaser Ophthalmological Center, Cuenca, Ecuador, from March to August 2019. Corneal indices were studied using Pentacam. Statistical correlation methods, Levene’s test, Fisher’s exact test, Cramérs’ V coefficient, and multiple correspondence analyses were used.


The variables refractive cylinder and central keratometry had a direct correlation with the corneal indices (p<0.001). An inverse correlation was obtained between central pachymetry and corneal indices (p<0.001). A high level of dependence on central KC index (CKI) (Cramér V = 0.785) and KC index (KI) (Cramér V = 0.775) was obtained with the diagnosis of KC.


Pentacam is a valuable tool in the analysis of corneal indices for the diagnosis of KC, given its high level of correlation with clinical refractive variables. The selection of candidates for refractive surgery, even when there is no diagnosis of KC, is strengthened with the analysis of the corneal indices. The indices with the most intense level of dependence with the diagnosis of KC are, in order, the following indices: CKI, KI, vertical asymmetry, minimum radius, and variation of the surface.

Keywords: Keratoconus, Indices, Pentacam, Keratometry, Cylinder, Pachymetry.

Abstract Information

Identifiers and Pagination:

Year: 2020
Volume: 14
Publisher Item Identifier: EA-TOOPHTJ-2020-5

Article History:

Electronic publication date: 17/7/2020
Collection year: 2020

© 2020 Alvarez et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the University of Cuenca. Exilaser Ophthalmological Center, Cuenca, Ecuador; E-mail: