Relationship between Blood Pressure and Retrobulbar Blood Flow in Dipper and Nondipper Primary Open-Angle Glaucoma Patients

Background/AimsAn altered haemodynamic profile for various ocular posterior segment capillary beds has been documented in primary open-angle glaucoma (POAG). POAG may also involve abnormal non-ocular blood flow, and the nailfold capillaries, which are not affected by elevated intraocular pressure (IOP), are readily assessable.MethodsWe measured resting nailfold capillary blood flow in 67 POAG and 63 control subjects using video capillaroscopy. Masked readers tracked blood column voids between consecutive, registered image sequence frames, measured vessel diameter and calculated blood flow. We used multiple logistic regression to investigate the relation between nailfold capillary blood flow and POAG. In secondary analyses, we stratified cases by maximum IOP and concurrent topical beta-blocker use.ResultsMean (±SD) blood flow in picolitres per second was 26.8±17.6 for POAG cases and 50.1±24.2 for controls (p<0.0001). After adjustment for demographic and clinical factors including blood pressure and pulse, every picolitre per second increase in resting nailfold blood flow was associated with a 6% (95% CI 0.92 to 0.96) reduced odds of POAG (p<0.0001). Similar relations between nailfold capillary blood flow and POAG were found for cases stratified by maximum known IOP and for cases stratified by concurrent topical beta-blocker use.ConclusionReduced resting nailfold capillary blood flow is present in POAG independent of covariates such as blood pressure, pulse and IOP.

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Color Doppler Imaging and Ocular Pulse Amplitude in Glaucomatous and Healthy Eyes

European Journal of Ophthalmology ◽

10.1177/112067210901900410 ◽

2009 ◽

Vol 19 (4) ◽

pp. 580-587 ◽

Cited By ~ 23

Author(s):

Ingeborg Stalmans ◽

Alon Harris ◽

Steffen Fieuws ◽

Thierry Zeyen ◽

Veerle Vanbellinghen ◽

...

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Primary Open Angle Glaucoma ◽

Open Angle Glaucoma ◽

Corneal Thickness ◽

Healthy Controls ◽

Open Angle ◽

Blood Flow Velocities ◽

Retrobulbar Vessels ◽

Flow Velocities

Purpose To determine factors influencing color Doppler imaging (CDI) measurements, to compare retrobulbar flow velocities between patients with glaucoma and healthy controls, and to describe the correlation between CDI and ocular pulse amplitude (OPA). Methods Patients with normal tension (n=28) or primary open angle glaucoma (n=19) and healthy controls (n=22) underwent CDI and OPA measurements. Intraocular pressure, corneal thickness, blood pressure, and heart rate were also measured. Spearman correlations were used to explore relations among these variables. A regression model for repeated measures was applied to compare between diagnostic groups the flow velocity indices in the retrobulbar vessels. Results Retrobulbar diastolic blood flow velocities correlated with diastolic blood pressure and perfusion pressure (range of Spearman rho [ρ] coefficients=0.25–0.28; P=0.044–0.013 for the different vessels). Corneal thickness showed a positive correlation with systolic and diastolic flow velocities in the central retinal artery (ρ=0.29 and 0.31; P=0.017 and 0.011 for peak systolic and end diastolic velocity, respectively). Systolic and diastolic blood flow velocities were reduced in the retrobulbar vessels of patients with normal tension glaucoma (P=0.0004) as well as primary open angle glaucoma (P=0.003) compared to healthy controls. A correlation was found between OPA and the resistive index in the retrobulbar vessels of the healthy controls (range ρ=0.42–0.53; P=0.059–0.014). Conclusions Retrobulbar blood flow velocities are reduced in patients with primary open angle glaucoma and normal tension glaucoma. Blood pressure and corneal thickness may influence CDI measurements. OPA correlates with the resistive index in CDI.

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