Doheny Retina Institute, Los Angeles, CA, USA,
Graefes Arch Clin Exp Ophthalmol. 2010 May;248(5):675-80. doi: 10.1007/s00417-009-1298-9. Epub 2010 Feb 17.
The purpose of this study is to measure blood flow velocity of rabbit retinal vessels using a 45-MHz ultrasonic Doppler system with a needle transducer.
A high-frequency pulsed Doppler system that utilizes a 45-MHz PMN-PT needle transducer was developed to measure retinal blood flow velocity in situ. The pulsed Doppler allowed the differentiation of retinal from choroidal blood flow velocity. The needle transducer was inserted into the vitreous cavity through a 20-gauge incision port to access the retinal vessels. The first phase of the experiment evaluated the reproducibility of the measurements. The second phase measured velocities at four positions from the optic disc edge to the distal part of each vessel in nine eyes for the temporal and six eyes for the nasal portions. The angle between the transducer and the retinal vessel at each site was measured in enucleated rabbit eyes to estimate and compensate for measurement errors.
In the first phase, the average measurement error was 5.97 +/- 1.34%. There was no significant difference comparing all eyes. In the second phase, the velocities gradually slowed from the disc edge to the distal part, and temporal velocities were faster than nasal velocities at all measurement sites.
This study demonstrated the feasibility of reliably measuring retinal blood flow velocity using a 45-MHz ultrasonic Doppler system with a needle transducer.
本研究旨在使用 45MHz 超声多普勒系统和针状换能器测量兔视网膜血管的血流速度。
开发了一种利用 45MHzPMN-PT 针状换能器的高频脉冲多普勒系统，以原位测量视网膜血流速度。脉冲多普勒可区分视网膜和脉络膜的血流速度。针状换能器通过 20 号切口端口插入玻璃体腔，以进入视网膜血管。实验的第一阶段评估了测量的可重复性。第二阶段测量了 9 只眼颞侧和 6 只眼鼻侧从视盘边缘到每个血管远端的四个位置的速度。在兔眼眼球摘除术中测量了每个部位换能器与视网膜血管之间的角度，以估计和补偿测量误差。
在第一阶段，平均测量误差为 5.97 +/- 1.34%。所有眼睛之间没有显著差异。在第二阶段，速度从视盘边缘向远端逐渐减慢，在所有测量部位，颞侧速度均快于鼻侧速度。
本研究表明，使用 45MHz 超声多普勒系统和针状换能器可靠测量视网膜血流速度是可行的。
