Association between Corneal Deformation Amplitude and Posterior Pole Profiles in Primary Open-Angle Glaucoma

Abstract

To investigate the relationships between corneal deformation amplitude and posterior pole profiles, including β-zone parapapillary atrophy (βPPA), optic disc tilt ratio, torsion degree, and disc-foveal angle, in patients with glaucoma. Cross-sectional study. A total of 107 patients with glaucoma. Each patient underwent measurement of deformation amplitude with Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany), color optic disc photography, red-free retinal nerve fiber layer photography, axial length measurement, and 24-2 standard automated perimetry. From fundus photographs, the βPPA area, optic disc tilt ratio, torsion degree, and disc-foveal angle were obtained. Pearson's correlation was used to determine the relationships between deformation amplitude and posterior pole profiles. To determine the factors associated with the posterior pole profiles, univariate and multivariate regression analyses were performed. Deformation amplitude, βPPA area, optic disc tilt ratio, torsion degree, and disc-foveal angle. The study included 50 men (46.7%) and 57 women (53.3%). The mean age was 55.38±14.14 years. The mean tilt ratio, torsion degree, and disc-foveal angle were 1.16±0.14, 10.26±7.63°, and 7.60±3.64°, respectively. The mean βPPA area was 18 211.00±28 725.53 pixels. The βPPA (r= 0.391, P < 0.001) and tilt ratio (r= 0.408, P < 0.001) had significant relationships with deformation amplitude after adjusting for intraocular pressure (IOP). Torsion degree and disc-foveal angle showed no significant relationship with deformation amplitude. The βPPA area was associated with deformation amplitude and axial length in both univariate (P=0.008 and 0.006, respectively) and multivariate (P= 0.035 and <0.001, respectively) regression analyses. The tilt ratio was associated with deformation amplitude in univariate regression analysis (P= 0.002), but not inmultivariate regression analysis. Axial length was significantly associated with the tilt ratio in both univariate (P< 0.001) and multivariate (P < 0.001) regression analyses. Deformation amplitude was associated with PPA area and tilt ratio in patients with glaucoma, although in our data set βPPA area and tilt ratio were not associated with visual field mean deviation.