Abstract
Purpose:
To establish the correlation between corneal variables (determined using the Pentacam) and optic nerve head (ONH) variables (determined using the HRT) in a sample oh healthy volunteers and another sample of patients diagnosed with primary open angle glaucoma (POAG).
Methods:
75 healthy eyes and 73 eyes with POAG were examined. Corneal variables analyzed were corneal volume (CVol), central corneal thickness (CCT), overall corneal thickness (OvCT), the mean thickness of a circular zone centered at the corneal apex of 1 mm radius (zone I) and the mean thickness of several concentric rings, also centered at the apex until the limbus, each of 1 mm width (zones II to VI respectively); ONH variables were disc area (DAr), cup area (CAr), rim area (RAr), cup to disc area ratio (CDRa), cup volume (CVol), rim volume (RVol), mean cup depth (MCD), maximum cup depth (MaCD), height variation contour (HVC), cup shape measure (CSM), mean retinal nerve fiver layer (RNFL) thickness (MRNFL), RNFL cross sectional area (RNFLAr), maximum contour elevation (MCEle) and minimum contour depression (MCDep). Pearson correlation between the set of corneal variables and the set of ONH variables were obtained for both healthy and glaucomatous eyes.
Results:
For the healthy group, significant Pearson correlations were: CCT-DAr (-0.48; p<0.0001), Zone I-DAr (-0.503; p<0.0001), Zone II-DAr (-0.443; p<0.0001) and Zone I-MCD (-0.359; p<0.0001); for the POAG, significant correlations were: CCT-CDRa (-0.402; p<0.0001), CCT-RVol (-0.385; p<0.0001), Zone I-CDRa (-0.418; p<0.0001), Zone II-CDRa (-0.405; p=0.006), Zone I-CSM (-0.415; p=0.002), Zone II-CSM (-0.405; p=0.01), Zone IV-HVC (0.378; p=0.02); Zone V-HVC (0.388, p<0.0001).
Conclusions:
For healthy subjects, there is a significant negative correlation between central and paracentral corneal thicknesses with optic disc area. For the POAG group, there is a significant negative correlation between central and paracentral corneal thicknesses with cup-disc ratio and cup shape measure and a positive correlation between peripheral corneal thicknesses with height variation contour.
Keywords: 627 optic disc •
550 imaging/image analysis: clinical •
479 cornea: clinical science