Posters

Correlation between corneal curvature parameters and corneal biomechanical behavior in keratoconus

Poster Details

First Author: S.Rodrigo Rey SPAIN

Co Author(s): R. Cañones-Zafra   G. Bolívar   M. García-González   M. Teus           

Abstract Details

Purpose:

To determine the correlation, in the keratoconic corneas, between several parameters related to the degree of the corneal ectasia (anterior and posterior elevation and maximum anterior Keratometry) obtained by the high resolution rotating Scheimpflug camera (Pentacam HR®, Oculus) and the corneal biomechanical behavior, evaluated with the Corvis Scheimpflug technology (Corvis ST®, Oculus).

Setting:

Department of Ophthalmology, Príncipe de Asturias University Hospital, Alcalá de Henares, Madrid, Spain.

Methods:

In this observational cross-sectional study, 65 eyes with keratoconus were studied. A tomography scan was taken with the Pentacam HR® followed by a biomechanical measurement using the Corvis ST. For each cornea we analyzed the anterior elevation, the anterior maximum curvature (Kmax), the posterior elevation and the new dynamic corneal response (DCR) parameters (DA ratio, integrated radius, ARTh, SP-A1, CBI), in addition to the deformation amplitude (DA). Linear regression analysis and Pearson’s correlation coefficient were obtained.

Results:

Mean anterior elevation was 15.75±11.63 (range from -5 to+55 μm), posterior elevation 38.96±23.07 (range from +5 to+105) and Kmax 51.11±5.2 (range from 42.2 to66.1). DA ratio, integrated radius, ARTh, SP-A1, CBI and DA mean values were 5.09±0.90, 9.69±2.06, 255.71±116.35, 82.31±19.21, 0.85±0.26, 127±1.13 respectively. A significant correlation (p value <0.05) was obtained between the three tomographic and all the biomechanical parameters analyzed (except for DA,p=0.7) in all cases. R2 coefficient for the correlations between the DCR parameters and the Kmax were higher than those obtained with both the posterior and anterior elevation.

Conclusions:

Our results show a significant correlation between the DCR and the anterior, posterior or keratometric parameters in keratoconus disease, except for DA; thus, those Corvis ST DCR parameters could be considered as severity markers, reflecting the degree of the corneal weakening. Kmax seems to be better than the elevation parameters as a surrogate of the corneal rigidity. On the other hand, although DA seems to accurately differentiate between normal and ectatic corneas, it seems not to characterize the severity of the disease.

Financial Disclosure:

None