Papas Eric B
Cooperative Research Centre for Eye Research and Technology, University of New South Wales, Sydney, Australia.
Eye Contact Lens. 2003 Jan;29(1 Suppl):S72-4; discussion S83-4, S192-4. doi: 10.1097/00140068-200301001-00020.
Increases in limbal vascular blood flow frequently occur as an accompaniment to conventional soft contact lens wear. This study attempted to discover whether these changes can be induced by the direct influence of oxygen alone in the absence of contact lenses.
Nine people were subjected to monocular anoxia by bathing one randomly chosen eye with 100% nitrogen using gas-tight goggles. Their other eyes served as controls and were exposed to normal air throughout the study. Vascular changes were quantified by image capture and subsequent analysis, with the change in the proportion of the image corresponding to blood vessels (per area) being used as the measure of hyperemia.
Nitrogen-exposed eyes showed significantly greater hyperemia (mean perarea change +/- 95% confidence interval, 0.023 +/- 0.016 compared with control eyes, -0.013 +/- 0.013; P=0.004, paired t test).
Reduced oxygen concentration at the ocular surface induces more blood flow in limbal vessels. This result provides further evidence that similar changes occurring during soft contact lens wear are caused by lens-induced hypoxia.
角膜缘血管血流量增加常伴随传统软性隐形眼镜佩戴出现。本研究试图探究在无隐形眼镜的情况下，仅氧气的直接影响是否能引发这些变化。
9人通过使用气密护目镜用100%氮气冲洗一只随机选择的眼睛来使其单眼缺氧。在整个研究过程中，他们的另一只眼睛作为对照，暴露于正常空气中。通过图像采集及后续分析对血管变化进行量化，将图像中对应血管的比例（每单位面积）变化作为充血的衡量指标。
暴露于氮气的眼睛显示出显著更大程度的充血（平均每单位面积变化±95%置信区间，0.023±0.016，而对照眼睛为-0.013±0.013；P = 0.004，配对t检验）。
眼表氧浓度降低会诱导角膜缘血管血流量增加。这一结果进一步证明，软性隐形眼镜佩戴期间出现的类似变化是由镜片引起的缺氧所致。
