Abstract
Purpose :
To investigate the dependencies between corneal Optical Coherence Tomography (OCT) speckle distribution parameters, dynamic corneal response parameters and ocular biometrics, under controlled intraocular pressure (IOP) conditions.
Methods :
Custom designed, automated syringe pump was used to change and control IOP values in the anterior chamber of ten porcine eyes, within the maximum of 8h postmortem. At each IOP level, in the range of 10-40 mmHg with a step of 5 mmHg, the study protocol followed the sequence: 1) ocular biometry (IOL Master, Zeiss), 2) acquisition of corneal speckle using spectral optical coherence tomography (SOCT Copernicus REVO, Optopol), and 3) three times repeated measurement of corneal deformation parameters (Oculus Corvis ST). Gamma distribution with parameters aG (scale) and vG (shape) was used to fit the speckle intensity envelope in the region of interest encompassing the central corneal stroma from three horizontal and three vertical OCT B-scans. Median values of Gamma and deformation parameters, and averaged biometric ones were included in the statistical analysis using one-way repeated measures ANOVA. Partial correlation was performed to investigate the dependencies between corneal OCT speckle parameters and those of corneal deformation and ocular biometrics, with IOP set as a control variable.
Results :
IOP statistically significantly differentiated the aG (p<0.001) and vG (p=0.001) parameters. The scale parameter was more related to the dynamic corneal response parameters, although it was found to be independent from the central corneal thickness measured biometrically (p=0.071). The highest correlation was observed between aG and the maximum of corneal deflection amplitude (R=−0.603, p<0.001, see Fig.).
Conclusions :
An association was found between corneal biomechanical parameters and corneal microstructure, measured indirectly by evaluating corneal speckle distribution.
This is a 2020 ARVO Annual Meeting abstract.