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. 1999 Jul;83(7):809-13.
doi: 10.1136/bjo.83.7.809.

Glaucoma patients demonstrate faulty autoregulation of ocular blood flow during posture change

D W Evans  1 , A Harris, M Garrett, H S Chung, L Kagemann
Affiliations

Glaucoma patients demonstrate faulty autoregulation of ocular blood flow during posture change

D W Evans et al. Br J Ophthalmol. 1999 Jul.

Abstract

Background/aims: Autoregulation of blood flow during posture change is important to ensure consistent organ circulation. The purpose of this study was to compare the change in retrobulbar ocular blood flow in glaucoma patients with normal subjects during supine and upright posture.

Methods: 20 open angle glaucoma patients and 20 normal subjects, similar in age and sex distribution, were evaluated. Blood pressure, intraocular pressure, and retrobulbar blood velocity were tested after 30 minutes of sitting and again after 30 minutes of lying. Retrobulbar haemodynamic measures of peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were obtained in the ophthalmic and central retinal arteries using colour Doppler imaging (CDI).

Results: When changing from the upright to supine posture, normal subjects demonstrated a significant increase in OA EDV (p = 0.016) and significant decrease in OA RI (p = 0.0006) and CRA RI (p = 0.016). Glaucoma patients demonstrated similar changes in OA measures of EDV (p = 0.02) and RI (p = 0.04), but no change in CRA measures.

Conclusion: Glaucoma patients exhibit faulty autoregulation of central retinal artery blood flow during posture change.

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Figures

Figure 1
Figure 1
Peak systolic (PSV) and end diastolic blood flow (EDV) velocities and resistance index (RI) for the ophthalmic artery (OA) in the sitting and supine position for glaucoma patients and normal subjects (mean (SEM)) The + indicates a significant change within groups from the sitting to supine posture.
Figure 2
Figure 2
Peak systolic (PSV) and end diastolic blood flow (EDV) velocities and resistance index (RI) for central retinal artery (CRA) in the sitting and supine position for glaucoma patients and normal subjects (mean (SEM)). The + indicates a significant change within groups from the sitting to supine posture. The * indicates a significant difference between groups in either of the two body positions.
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