Physiological perturbation of ocular and cerebral blood flow as measured by scanning laser ophthalmoscopy and color Doppler imaging.
Physiological perturbation of ocular and cerebral blood flow as measured by scanning laser ophthalmoscopy and color Doppler imaging.
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DOI：
10.1016/0039-6257(94)90050-7
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发表时间：
1994-05-01
影响因子：
5.1
通讯作者：
Martin, B
中科院分区：
文献类型：
--
作者：
Harris, A;Arend, O;Martin, B
健康的视网膜血流调节仍然缺乏描述。我们假设，视网膜灌注的控制，以提供恒定的O2输送到该组织，并在视网膜血流的变化，以响应化学刺激平行的变化，颈动脉和球后灌注。因此，在11个正常的眼睛检查的年轻人中，我们测量了视网膜血流指数（通过荧光素血管造影期间的扫描激光检眼镜[SLO]）和颈动脉、眼动脉和视网膜中央动脉血流指数（通过多普勒成像[CDI]），在控制，缺氧（肺泡PO 2 = 55 +/- 3 mmHg）和高氧（肺泡PO 2 = 655 +/- 18 mmHg）条件下。按顺序平衡这三种条件，并在每种条件下维持等碳酸血症。视网膜动脉平均染色速度和动静脉通过时间（通过SLO测量）在高氧时减慢，在缺氧时加快，与动脉O2含量的变化大致成比例（+/- 10%; p < 0.05）。在7名受试者中，获得视网膜动脉直径的相对测量值，无论是缺氧还是高氧显着改变血管直径。与此同时，平均视网膜毛细血管通过速度是独立的PO 2，这表明，在健康的，视网膜毛细血管可能会被招募为PO 2福尔斯下降。未发现O2诱导的颈动脉、眼动脉或视网膜中央动脉血流速度（通过CDI）的变化，尽管变异系数很大（CDI为30%，SLO为14%）可能导致了这种失败。我们的结论是，在等二氧化碳条件下，视网膜灌注可以调节，以提供恒定的O2输送。（250字处删节）
Retinal blood flow regulation in health remains poorly described. We hypothesized that retinal perfusion is controlled to provide constant O2 delivery to that tissue, and that changes in retinal blood flow in response to chemical stimuli parallel changes in carotid and retrobulbar perfusion. Accordingly, in 11 young adults with normal eye examinations, we measured retinal blood flow indices (via scanning laser ophthalmoscopy [SLO] during fluorescein angiography) and carotid, ophthalmic, and central retinal arterial blood flow indices (via Doppler imaging [CDI]) under control, hypoxic (alveolar PO2 = 55 +/- 3 mmHg) and hyperoxic (alveolar PO2 = 655 +/- 18 mmHg) conditions. The three conditions were counterbalanced in order and isocapnia was maintained in each. Retinal arterial mean dye velocity and arteriovenous passage time, as measured by SLO, were slowed by hyperoxia and accelerated by hypoxia, in rough proportion to the changes in arterial O2 content (+/- 10%; p < 0.05). In the seven subjects in which relative measurements of retinal arterial diameters were obtained, neither hypoxia nor hyperoxia significantly altered vessel diameter. At the same time, mean retinal capillary transit velocity was independent of PO2, suggesting that, in health, retinal capillaries may be recruited as PO2 falls. O2-induced changes in carotid, ophthalmic, or central retinal arterial blood flow velocities (via CDI) were not found, though a wide coefficient of variation (30% for CDI vs. 14% for SLO) may have contributed to this failure. We conclude that, under isocapnic conditions, retinal perfusion may be regulated to provide constant O2 delivery.(ABSTRACT TRUNCATED AT 250 WORDS)