The relationship of corneal curvature with corneal biomechanical deformation response by Scheimpflug imaging analysis in normal eyes

Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Monday 15/09/2014 | 17:00-18:30

Paper Time: 18:12

Venue: Capital Hall A

First Author: : W.Wan Abdul Halim MALAYSIA

Co Author(s): :    M. Nesssim   S. Shah   S. Naroo        

Abstract Details

Purpose:

To examine the correlation of the corneal curvature measurement by the new corneal topography instrument, the Keratograph 5 (Oculus Optikgerate, Germany) with corneal biomechanical deformation response parameters by Corvis ST (Oculus Optikgerate, Germany).

Setting:

A prospective cross sectional study was done at Aston University, Birmingham. The study was approved by the institution’s ethics committee and the research followed the tenets of the Declaration of Helsinki.

Methods:

The study subjects underwent three repeated examinations of the corneal curvature by Keratograph 5 and dynamic corneal deformation analysis by Corvis ST. The correlation between the central radius of corneal curvature were analysed against the corneal biomechanical deformation response parameters. The corneal biomechanical deformation response parameters analysed were first applanation corneal response time (A1T), length (A1L) and velocity(A1V); second applanation corneal response time(A2T), length (A2L) and velocity (A2V); as well as the corneal characteristics at the point of highest concavity: time (HCT), deformation amplitude (DA), distance between bending points of the cornea (Dist), and concave radius of curvature (rCurv). Pearson’s test of correlation by SPSS version 21.0 was used for the analysis of the correlation coefficient. Statistical value of significance (p value) was set at 0.05.

Results:

The mean radius of corneal curvature (R) was 7.74 ± 0.23 mm. There was moderate correlation with A2T and rCurv with correlation coefficient (r value) of -0.31 and 0.34 respectively. (p<0.05)

Conclusions:

During air-puff deformation with Corvis ST, the time during second corneal deformation response is reduced with higher corneal curvature. However, the radius of the corneal concavity was noted to increase with the increment of the central corneal curvature.

Financial Interest:

NONE