Stanton A V, Mullaney P, Mee F, O'Brien E T, O'Malley K
Department of Clinical Pharmacology, Royal College of Surgeons in Ireland.
J Hypertens. 1995 Jan;13(1):41-8.
To find an objective, sensitive method for quantifying microvascular alterations associated with level of blood pressure and age.
A prospective cross-sectional study.
Seventy-four previously untreated hypertensive patients, referred to a hospital outpatients department, and 26 normotensive volunteers participated. Twenty-four-hour ambulatory blood pressure monitoring and bilateral fundal photography were performed. The fundal photographs were projected on a screen such that the optic disc filled a circle of radius 5 cm. Microvessels crossing the border of a concentric circle of radius 20 cm were identified as arteriolar or venular, counted and their luminal diameters measured.
Arteriolar and venular numbers, mean diameters and vascularities (arteriolar and venular vascularities defined as the sum of arteriolar and venular diameters, respectively).
The technique was reproducible. As blood pressure increased, arteriolar vascularity declined and venular vascularity increased. These associations resulted in a strong inverse correlation between blood pressure level and the ratio arteriolar vascularity: venular vascularity (r = 0.48, P < 0.001). Arteriolar number declined with increasing diastolic blood pressure (r = 0.22, P < 0.05). Mean arteriolar diameter appeared to have a U-shaped relationship with diastolic blood pressure levels (r = 0.27, P < 0.05). Venular dilation was associated with increasing blood pressure levels (r = 0.22, P < 0.05). Mean arteriolar and venular diameters declined significantly with age (r = 0.33 and 0.26, respectively; P < 0.01) and there was no association between arteriolar vascularity:venular vascularity ratio and age.
The method detected disparate retinal microvascular alterations with age and blood pressure. The arteriolar vascularity:venular vascularity ratio shows promise as a non-invasive, prognostic and therapeutic guide in hypertension.
寻找一种客观、灵敏的方法来量化与血压水平和年龄相关的微血管改变。
一项前瞻性横断面研究。
74例此前未接受治疗的高血压患者（转诊至医院门诊）和26名血压正常的志愿者参与研究。进行了24小时动态血压监测和双眼眼底照相。将眼底照片投射到屏幕上，使视盘填满半径为5厘米的圆圈。识别穿过半径为20厘米同心圆边界的微血管为小动脉或小静脉，计数并测量其管腔直径。
小动脉和小静脉数量、平均直径和血管密度（小动脉和小静脉血管密度分别定义为小动脉和小静脉直径之和）。
该技术具有可重复性。随着血压升高，小动脉血管密度下降，小静脉血管密度增加。这些关联导致血压水平与小动脉血管密度：小静脉血管密度之比呈强负相关（r = 0.48，P < 0.001）。小动脉数量随舒张压升高而减少（r = 0.22，P < 0.05）。平均小动脉直径与舒张压水平呈U形关系（r = 0.27，P < 0.05）。小静脉扩张与血压水平升高相关（r = 0.22，P < 0.05）。平均小动脉和小静脉直径随年龄显著下降（分别为r = 0.33和0.26；P < 0.01），且小动脉血管密度：小静脉血管密度之比与年龄无关。
该方法检测到了与年龄和血压相关的不同视网膜微血管改变。小动脉血管密度：小静脉血管密度之比有望成为高血压的一种非侵入性、预后和治疗指导指标。
