The effect of air pulse-driven whole eye motion on the association between corneal hysteresis and glaucomatous visual field progression

Abstract

Corneal hysteresis (CH) measured with Ocular Response Analyzer (Reichert: ORA) has been reported to be closely related to the glaucomatous visual field (VF) progression. The air pulse applied to an eye not only induces corneal deformation, but also whole eye motion (WEM), which may result in an inaccurate measurement of CH. Here we investigated the influence of air pulse-driven WEM measured with the Corivs ST (CST®, OCULUS) on the relationship between CH and VF progression in primary open angle-glaucoma patients. Using the CST parameters of the maximal WEM displacement (WEM-d) and the time to reach that displacement (WEM-t), the eyes were classified into subgroups (WEM-d low- and high-group, and WEM-t short- and long-group). For the whole population and all subgroups, the optimal linear mixed model to describe mean of total deviation (mTD) progression rate with eight reliable VFs was selected from all combinations of seven parameters including CH. As a result, optimal models for the mTD progression rate included CH in the whole population, the WEM-d low- group and the WEM-t short-group, but not in the WEM-d high-group and the WEM-t long-group. Our findings indicated association between CH and glaucomatous progression can be weakened because of large WEM.

A novel method for quantifying the biomechanical parameters of orbital soft tissue using a corneal dynamic scheimpflug analyser: a retrospective study

“…Eyeball displacement measured using the Corvis ST is true eyeball movement and not just axial shortening and elongation of eyeball induced by the air puff based on the fact that the eyeballs moved forward again after returning to their original corneal contour (S1Video). This finding is consistent with the findings of previous studies [21, 23, 26–29, 33, 34].…”

“…Jung et al found that unadjusted WEM was smaller in glaucoma group compared to normal group [28]. Aoki et al measured WEM in open angle glaucoma and obtained the relationship between WEM and axial length of eyeball [29].…”

Relationship Between the Shift of the Retinal Artery Associated With Myopia and Ocular Response Analyzer Waveform Parameters

“…Another previous study reported that the maximum deformation amplitude measured by CST was associated with the size of β-zone parapapillary atrophy,16 which has been reported to be associated with the development, severity, progression, and location of glaucoma 17–20. Our recent studies also suggested that CST parameters were associated with the activity and prognosis of angioid streaks,21 and also the severity22 and progression23 of glaucoma. However, a different study reported no relationship between ORA-measured corneal hysteresis (CH) and β-zone parapapillary atrophy 24.…”

Corneal deflection amplitude and visual field progression in primary open-angle glaucoma

“…In line with this speculation, corneal hysteresis has also been suggested as risk factor for glaucoma progression in several studies. [7–12] The biomechanical property of the cornea might reflect the elasticity and distensibility of the posterior ocular tissues leading to increased susceptibility of the optic nerve head to glaucomatous damage.…”