Holden B A, Sweeney D F, Vannas A, Nilsson K T, Efron N
Invest Ophthalmol Vis Sci. 1985 Nov;26(11):1489-501.
The effects of long-term extended wear of soft contact lenses on the human cornea were determined by examining 27 patients who had worn a high water content hydrogel contact lens in 1 eye only for an average of 62 +/- 29 months (mean +/- SD). The other eye, which was either emmetropic or amblyopic, acted as a control. The lens-wearing eye showed a 14.8% reduction in epithelial oxygen uptake (P less than 0.001), a 5.6% reduction in epithelial thickness (P less than 0.05), a 2.3% reduction in stromal thickness (P less than 0.05), the induction of epithelial microcysts, and a 22.0% increase in endothelial polymegathism (P less than 0.001). Endothelial cell density was unaffected by extended lens wear. No interocular differences in any of these physiological characteristics were found in a matched control group of anisometropic and amblyopic subjects who did not wear contact lenses. The patients ceased lens wear for up to one month and recovery of corneal function was monitored during this period. Epithelial oxygen uptake and thickness recovered within 33 days of lens removal. The number of microcysts increased over the first 7 days, but decreased thereafter; some microcysts were still present 33 days after lens removal. Recovery from stromal thinning had not occurred after 33 days following lens removal. There was a slight reduction in polymegathism in some patients, but overall this was not statistically significant. These findings establish (1) that the extended wear of hydrogel lenses induces significant changes in all layers of the cornea; (2) that lens wear suppresses aerobic epithelial metabolism, which may compromise the epithelial barrier to infection; and (3) that changes to the stroma and endothelium are long-lasting. Lens-induced effects on corneal physiology can be minimized by fitting lenses that have greater oxygen transmissibility (are thinner), are more mobile, more frequently removed, and more regularly replaced.
通过检查27例患者来确定长期延长佩戴软性隐形眼镜对人角膜的影响。这些患者仅在一只眼睛中佩戴高含水量水凝胶隐形眼镜，平均佩戴时间为62±29个月（平均值±标准差）。另一只眼睛，无论是正视眼还是弱视眼，作为对照。佩戴隐形眼镜的眼睛上皮氧摄取量降低了14.8%（P<0.001），上皮厚度降低了5.6%（P<0.05），基质厚度降低了2.3%（P<0.05），诱导了上皮微囊肿，内皮多形性增加了22.0%（P<0.001）。内皮细胞密度不受延长佩戴隐形眼镜的影响。在未佩戴隐形眼镜的屈光参差和弱视受试者的匹配对照组中，未发现这些生理特征存在眼间差异。患者停止佩戴隐形眼镜长达一个月，并在此期间监测角膜功能的恢复情况。上皮氧摄取量和厚度在摘除隐形眼镜后33天内恢复。微囊肿数量在最初7天内增加，但此后减少；摘除隐形眼镜33天后仍有一些微囊肿存在。摘除隐形眼镜33天后，基质变薄并未恢复。一些患者的多形性略有降低，但总体而言这在统计学上并不显著。这些发现表明：（1）水凝胶镜片的延长佩戴会引起角膜各层的显著变化；（2）佩戴镜片会抑制需氧上皮代谢，这可能会损害上皮对感染的屏障；（3）基质和内皮的变化是持久的。通过佩戴具有更高透氧性（更薄）、更易移动、更频繁摘除和更定期更换的镜片，可以将镜片对角膜生理的影响降至最低。
