Abstract
Purpose :
Corneal biomechanical and physical properties have been associated with visual field (VF) progression and have been correlated to differences in disease severity. This study investigates whether inter-eye asymmetry of corneal properties is associated with asymmetry in rates of visual field loss in patients with primary open angle glaucoma (POAG).
Methods :
This prospective observational longitudinal study followed 127 patients with POAG for a mean follow-up period of 4.3 years. All participants underwent corneal hysteresis (CH) and central cornea thickness (CCT) measurements at baseline, and standard automated perimetry (SAP), and intraocular pressure (IOP) measurements obtained using Goldmann applanation tonometry (GAT) every 6 months. Rates of visual field progression were calculated using ordinary least square regression of SAP mean deviation (MD) values over time for each eye. A linear regression model was used to investigate the relationship between inter-eye asymmetry in CH and CCT and inter-eye differences in rates of change of SAP MD.
Results :
Patients had at baseline, mean MD of -6.17 ± 5.80 dB, CH of 9.1 ± 1.6 mmHg, CCT of 532.6 ± 42.7 µm; and mean IOP of 14.23 ± 3.13 mmHg during follow-up. The mean rates of change of MD SAP were -0.11 ± 0.74 dB/year for the better eye and -0.61 ± 0.85 dB/year for the worse eye. Asymmetry of CH was significantly associated with the difference between eyes on SAP MD rates of change, with 0.14 dB/year larger asymmetry for each 1 mmHg of difference (p=0.036). Asymmetry in CCT was not associated with difference on rates of MD change (p=0.288).
Conclusions :
Inter-eye asymmetry in CH was associated with increased asymmetry on rates of visual field change. These results give further support for the role of CH as a risk factor for glaucoma progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.