Purpose To analyze dynamics of retinal vessel dilation response to flicker light in patients with glaucoma and ocular hypertension. Patients and methods Response to flicker light was measured in retinal vessels by means of Retinal Vessel Analyzer. After the baseline 50 seconds long diameter recording of inferior and superior temporal artery and vein, three flicker stimulations of 20 seconds duration was applied, with a 80 seconds break in between. Area under the curve of the vessel diameter (AUC) was compared during 3 flicker periods in the open angle glaucoma patients group (POAG, n=47) and ocular hypertensives (OHT, n=46) and age-matched healthy controls (n=56) Results POAG eyes demonstrated smaller response of all vessels to flicker light in general than the other two groups (p=0.0008), but the response dynamics was significantly different between the groups (p=0.038), showing in three flicker periods a delayed increasing response in the POAG and OHT groups, and remaining stable in healthy subjects. Conclusion General vessel response to flicker light was decreased in POAG patients despite the slow improvement in repeated flicker stimulation, indicating an altered response pattern.

General vessel response to flicker light was decreased in POAG patients, compared to normal controls and OHT patients. In contrast to significant correlation between the two contralateral eyes of the flicker response itself, only its borderline correlation to IOP was seen. There was no correlation to the level of damage, altogether indicating a systemic dysregulation phenomenon. GRANTS: Swiss National Foundation Grant 3200B0-113685, Velux Stiftung Grant, Freie Akademische Gesellschaft (FAG) Grant, Pfizer Inc. Grant CLINICAL TRIAL REGISTRATION REFERENCE NUMBER: ClinicalTrials.gov NCT00430209.

Despite small differences between the morphologic and functional glaucomatous damage, IOP and perfusion parameters seem to contribute, at least in part, independently to both.

ABSTRACT.Purpose: To analyse a prognostic value of initial retinal vessel flicker response for the 3-year development of functional (visual field) and morphological (nerve fibre layer thickness) damage progression in primary open-angle glaucoma patients. Patients and methods: Initially, 70 patients were recruited, and flicker response was measured by standardized procedure with the retinal vessel analyser (RVA). Ocular coherence tomography of retinal nerve fibre layer (OCT RNFL) and a visual field testing were performed at beginning and every 6 months for 3 years; 56 patients completed the study. Results: No correlation was found between the progression of visual field (VF) mean defect and retinal nerve fibre layer (RNFL) thinning over 3 years on one and the maximal flicker reaction in arteries and veins on the other side (all p > 0.1). However, the calculated difference of examined parameters in the superior versus inferior retinal halves correlated significantly between the RNFL thinning and the initial maximal flicker response for arteries (p = 0.01) and veins (p = 0.003). Conclusion: This longitudinal study did not find a general correlation between initial retinal vessel response to flicker light and the glaucoma damage progression measured by OCT and VF, hence limiting the relevance of the RVA device as a predictor of future glaucomatous damage.