Synergic effect of corneal hysteresis and central corneal thickness in the risk of early-stage primary open-angle glaucoma progression

Abstract

Purpose To evaluate corneal hysteresis (CH), acquired with ocular response analyzer (ORA), as a risk factor for glaucoma progression in early-stage primary open-angle glaucoma (POAG). Methods In a historical cohort study, patients diagnosed in 2011 with early-stage POAG according to the Hodapp, Parrish and Anderson classification modified for Octopus perimetry and followed up until glaucomatous progression development; otherwise, observations were censored in October 2018. Cox regression was used to obtain hazard ratios (HR) to evaluate baseline variables (CH, central corneal thickness, gender, age IOP and glaucoma family history) as risk factors for perimetric glaucoma progression. A likelihood ratio test for interaction was performed in order to assess the effect of the combination of CH and CCT on the risk of progression. Results Of the cohort of 1573 patients, 11.38% developed early-stage POAG progression during the follow-up. The mean follow-up time was 3.28 ± 1.92 years. Patients without progression had a higher CH (11.35 ± 1.43 vs 9.07 ± 1.69 mmHg; p < 0.001) and CCT (570.75 ± 17.71 vs 554.51 ± 23.20; p < 0.001). In the multivariate analysis, each 1 mmHg of lower CH was associated with an increase of 2.13 times in the HR of progression (95% CI: 1.92-2.32; p < 0.001). CH hazard ratio was modified by CCT, with higher values of CCT and CH resulting in a higher HR of early glaucoma progression (p < 0.001). Conclusions CH can be considered as a risk factor of progression in early-stage POAG. The risk associated with CH changed depending on CCT values, acting synergistically slowing the risk of glaucoma progression with higher values.

Corneal Hysteresis, Intraocular Pressure, and Progression of Glaucoma: Time for a “Hyst-Oric” Change in Clinical Practice?

“…A study by Dana et al in 2015 [ 52 ] demonstrated a statistically significant, positive correlation between Visual Field Index (VFI) and CH, with lower CH values correlating with a lower VFI on Humphrey Visual Field testing. In a recent study published in 2021 by Jiménez-Santos et al [ 53 ], 1573 patients from a previous cohort study with POAG were analysed in terms of glaucoma progression with respect to multiple baseline parameters including CH and CCT. It was observed that patients without progression had higher CH values and higher CCT.…”

Early influence of endotamponade on corneal biomechanical parameters, central corneal thickness and accuracy of intraocular pressure measurement

“…Current studies suggest that in eyes with chronically elevated IOP, CCT is significantly reduced, what can be consistent with long-term increase in IOP related to silicon oil tamponade lasting 6-months in our patients 23 . The pathomechanism of CCT changes in patients with elevated IOP is not entirely clear 24 . It is suggested that CCT reduction in glaucomatous eyes may be the effect of remodeling of the corneal stroma under the increased IOP and pressure exerted on stromal collagen fibers 25 .…”

Correlation between Interocular Asymmetry of Corneal Hysteresis and Visual Field Defect in Glaucoma

“…CH was measured using an ocular response analyzer (ORA; Reichert Technologies Inc., Depew, NY, USA) as described previously [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The ORA is based on non-contact tomometer technology, which uses an air jet to apply force to the cornea and an electrooptical system to determine applanation.…”

“…However, other factors, such as blood flow reduction, impaired vascular autoregulation, dysfunctional neurovascular coupling, and corneal properties, are also thought to play a role in the pathogenesis of glaucoma. Regarding corneal properties, central corneal thickness (CCT) [1][2][3][4] and corneal hysteresis (CH) [5][6][7][8][9][10][11][12][13][14][15][16][17][18] have been reported to be risk factors for glaucoma. A lower CCT poses a risk for glaucoma progression, and has been found to be more prevalent among patients with severer glaucomatous damage [1][2][3][4].…”

“…CH is a dynamic biomechanical property of the cornea that measures its ability to resist deformation. Previous studies have reported that CH was lower in eyes with glaucoma than in normal eyes, and lower CH was associated with structural and functional progression of glaucoma [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. A possible method to investigate the effect of CH on the development and progression of glaucoma is to evaluate the correlation between interocular differences in CH and the severity and progression rate of glaucoma in both eyes of the same patient.…”