Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study

David Kuerten,Peter Walter,Konstantin Kotliar,Matthias Fuest,Niklas Plange,Muriel Hollstein

doi:10.1007/s10792-021-01876-0

Abstract

PurposeVascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry.Methods15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (−20.99 ± 10.49 profound hemispheric visual field defect vs −7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye.ResultsSignificant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p < 0.04 and p < 0.02 respectively) in-between the hemispheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance.ConclusionLocalized retinal vessel regulation is significantly altered in glaucoma patients with asymmetric altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.

Highlights

Glaucoma is an optic disc neuropathy, characterized by optic disc cupping, loss of vital nerve fibers and visual field defects
An ischemia–reperfusion damage vicious cycle has been proposed and disturbances in the venous part of the circulation have regularly been found in glaucoma patients [5,6,7,8]
In our study we were able to show, that intraocular differences in retinal vascular regulation can be recorded in glaucoma patients with profound altitudinal visual field defect asymmetry

Summary

Introduction

Glaucoma is an optic disc neuropathy, characterized by optic disc cupping, loss of vital nerve fibers and visual field defects. But widely accepted, ocular hemodynamics and ocular blood flow appear to be a critical factor in the pathogenesis of glaucoma [2,3,4]. An ischemia–reperfusion damage vicious cycle has been proposed and disturbances in the venous part of the circulation have regularly been found in glaucoma patients [5,6,7,8]. Changes in ocular blood flow (OBF) can precede visual field loss and may play a major role during the earliest stages of glaucoma [9]. Differences in OBF were reported between early glaucoma patients and healthy subjects, whereas the changes in middle- to late-stage glaucoma were minor [9]. Automated assessment of retinal vessel diameters showed significant alterations in glaucoma [10,11,12,13]

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Conclusion