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

Shuichiro Aoki,Ryo Asaoka,Masato Matsuura,Yoshiaki Kiuchi,Shunsuke Nakakura,Yoshitaka Nakao,Hiroshi Murata,Yuri Fujino

doi:10.1038/s41598-018-21424-8

Shuichiro Aoki, Ryo Asaoka + Show 6 more

Open Access

https://doi.org/10.1038/s41598-018-21424-8

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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.

Highlights

® Corivs ST (CST, OCULUS) on the relationship between Corneal hysteresis (CH) and visual field (VF) progression in primary open angleglaucoma patients
The air pulse can drive corneal deflection, and whole eye motion, which could result in an inaccurate CH measurement; the ORA-CH measurement validity relies on an assumption that the majority of energy generated by the air pulse contributes to corneal deflection but if this is not the case due to whole eye motion, it could result in an inaccurate measurement of CH and a weakened relationship between the measured CH value and the progression of glaucomatous VF damage
There was no significant difference in Variables age, [range], years old Goldmann applanation tonometry based-intraocular pressure (GAT-IOP), [range], mmHg Axial length (AL), [range], mm central corneal thickness (CCT), [range], μm Initial mean of total deviation (mTD), [range], dB CH, [range], mmHg

Summary

Introduction

® Corivs ST (CST , OCULUS) on the relationship between CH and VF progression in primary open angleglaucoma patients. Corneal hysteresis (CH) measured with Ocular Response Analyzer (Reichert: ORA) is closely related to the progression of glaucomatous visual field (VF) damage[1,2,3,4]. It reflects corneal damping capacity in response to air pressure-induced stress[5,6]. Recorded image sequences reveal that the air puff induces corneal backward deflection and, simultaneously, posterior movement of the whole cornea called “Whole Eye Motion (WEM)”; the WEM is summarized by two measurements of the maximal displacement (WEM-d) and the time taken to reach the maximal displacement (WEM-t). Since mechanical conditions in orbit is known to affect WEM9, we investigated the effect of topical usage of PGA prescribed for glaucoma patients on WEM along with other parameters because PGA induces histological and mechanical changes in orbital tissue and eyelids[10,11,12], cornea and sclera[13,14,15]

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