SHORT POSTERIOR CILIARY ARTERY BLOOD FLOW MEASUREMENTS IN HIGH TENSION PRIMARY OPEN ANGLE GLAUCOMA USING COLOR & SPECTRAL DOPPLER SONOGRAPHY
K.-G. Schmidt1, A. v. Rückmann1, V. Klingmüller2, A. Stein2, H. Stroh2, K.W. Jacobi1
Ocular perfusion is increasingly being discussed in the pathogenesis of the glaucomas. The choroid, a low resistance vascular structure carrying 85% of the total ocular blood flow, provides nourishment to and removal of potential toxic waste products from the non-vascularized outer layers of the retina, macula and optic disc region. This vascular structure is supplied by the short posterior cilary arteries (SPCAs), which also directly supply the optic nerve head. This study was designed to evaluate for retrobulbar hemodynamics in high tension primary open angle glaucoma patients (HTG) and healthy volunteers (CTL).
Methods: 12 HTG and 20 CTL without clinically relevant extracranial stenosis (< 50% reduction in vessel diameter) as excluded by sonography of common and internal carotid arteries, were evaluated using 9 MHz linear and phased array scanners (Elegra Advanced System, Siemens, Germany). Transmission energy was reduced to 40% (B-, C-, 8 D-modes), the most temporal SPCA being the vessel investigated.
Results (mean ± SD): In CTL SPCA peak systolic flow (cm/s) was 11.80 ± 2.01, enddiastolic flow (cm/s) was 3.54 ± 1.04, pulsatility index was 1.26 ± 0.30, and resistance index was 0.69 ± 0.10. When compared to CTL in HTG peak systolic flow was unchanged (p> 0.05), enddiastolic flow was sig. (p< 0.05) reduced whereas pulsatility and resistance indexes were sig. (p< 0.05) increased.
Conclusion: Color and spectral sonography showed a reduction in diastolic flow patterns and increased pulsatility and resistance indexes in HTG suggesting increased retrobulbar vascular resistance in SPCAs of these patients.
1Departments of Ophthalmology and 2 Diagnostic Radiology, U of Giessen