Papas E B, Vajdic C M, Austen R, Holden B A
Cooperative Research Centre for Eye Research and Technology, University of New South Wales, Sydney, Australia.
Curr Eye Res. 1997 Sep;16(9):942-8. doi: 10.1076/ceyr.16.9.942.5049.
To establish the temporal sequence of limbal hyperaemia in humans without contact-lens wear and during conventional and highly oxygen-permeable soft-contact-lens wear.
Two, 16-h, non-dispensing clinical studies were conducted, each incorporating 8 h of open eye with normal blinking, followed by 8 h of eye closure during sleep. In the first study, six non-habitual contact-lens wearers did not wear contact lenses. In the second study, the same subjects were each randomly assigned, in a double-masked fashion, to wear a conventional, thin, 38% water, pHEMA soft contact lens (SCL) in one eye and an experimental high Dk (EHD), 20%-water soft contact lens in the other. Limbal redness (LR) was graded, using a 0-4 scale with decimalised subdivisions, at baseline and after 4, 8 and 16 h. ANOVA was applied to the data, and the level for statistical significance was set at p < or = 0.005.
In the non-wearing eye, LR changes averaged 0.2 +/- 0.2 and 0.4 +/- 0.2 grades at 4 and 16 h, respectively (inferior quadrant). The corresponding values for SCL wear were 1.0 +/- 0.6 and 1.1 +/- 0.6, while for EHD wear they were 0.2 +/- 0.4 and 0.5 +/- 0.5. Both for the normal eye and those wearing EHD lenses, increases in LR were significant only during eye closure (p < 0.005). During SCL wear, significant and larger LR increases were seen after 4 h open eye wear (p < 0.005), with only relatively small further changes being observed over the next 12 h.
SCL wear induces a marked increase in limbal hyperaemia during open-eye wear, which is not seen either in the no lens situation or when EHD lenses are worn. The pattern of limbal hyperaemia for both the open and closed eyes during EHD lens wear is very similar to that for the no-lens situation. The mechanism whereby SCL induces excess limbal hyperaemia has not been absolutely established, but it may involve local hypoxia.
确定未佩戴隐形眼镜以及佩戴传统型和高透氧性软性隐形眼镜的情况下，人类角膜缘充血的时间顺序。
进行了两项为期16小时的非配适临床研究，每项研究包括8小时正常眨眼睁眼期，随后是8小时睡眠闭眼期。在第一项研究中，6名非习惯性隐形眼镜佩戴者不佩戴隐形眼镜。在第二项研究中，相同的受试者以双盲方式随机分配，一只眼睛佩戴传统的、薄的、含水量38%的聚甲基丙烯酸羟乙酯软性隐形眼镜（SCL），另一只眼睛佩戴实验性高Dk值（EHD）、含水量20%的软性隐形眼镜。在基线以及4、8和16小时后，使用0至4级评分标准（带有十进制细分）对角膜缘发红（LR）进行分级。对数据应用方差分析，统计学显著性水平设定为p≤0.005。
在未佩戴隐形眼镜的眼睛中，4小时和16小时时LR变化平均分别为0.2±0.2级和0.4±0.2级（下象限）。佩戴SCL时的相应值为1.0±0.6级和1.1±0.6级，而佩戴EHD时为0.2±0.4级和0.5±0.5级。对于正常眼睛和佩戴EHD镜片的眼睛，LR增加仅在闭眼期间显著（p<0.005）。佩戴SCL期间，睁眼佩戴4小时后LR显著且更大幅度增加（p<0.005），在接下来的12小时内仅观察到相对较小的进一步变化。
佩戴SCL在睁眼佩戴期间会导致角膜缘充血显著增加，这在未佩戴镜片或佩戴EHD镜片时均未出现。佩戴EHD镜片时睁眼和闭眼期间角膜缘充血模式与未佩戴镜片情况非常相似。SCL导致角膜缘充血过多的机制尚未完全明确，但可能涉及局部缺氧。
