Baer R M, Hill D W
Moorfields Eye Hospital, London.
Eye (Lond). 1990;4 ( Pt 5):751-6. doi: 10.1038/eye.1990.107.
Alterations in retinal vessel calibre on changing posture may indicate an autoregulatory response to changing perfusion pressure. The effect of passive tilting on retinal response in healthy individuals was investigated. Subjects were supported on a specially constructed tilting table. The control measurements were taken with the body in a 30 degrees head up position. Red-free fundus photographs were taken before, during and after a three minute period of 30 degrees head down tilting. Ten subjects were assessed (mean age 29 years: range 18-38). A total of 92 arteriolar and 86 venular sites were measured. On tilting to the head down position arterioles showed an early and significant decrease in calibre: mean -3.1% (p less than 0.001). Venules showed an increase of 3.7% (p less than 0.001). The response was not sustained throughout the period of tilting despite a maintained increase in ocular perfusion pressure, which was estimated in six of the subjects.
姿势改变时视网膜血管口径的变化可能表明对灌注压变化的一种自动调节反应。研究了被动倾斜对健康个体视网膜反应的影响。受试者被安置在特制的倾斜台上。在身体处于头抬高30度的位置时进行对照测量。在30度头向下倾斜三分钟的过程中及前后拍摄无赤眼底照片。评估了10名受试者（平均年龄29岁：范围18 - 38岁）。共测量了92个小动脉部位和86个小静脉部位。倾斜至头向下位置时，小动脉口径早期即出现显著减小：平均减小3.1%（p < 0.001）。小静脉口径增加了3.7%（p < 0.001）。尽管在六名受试者中估计眼灌注压持续升高，但在整个倾斜期间这种反应并未持续。
