Kelly L D, Long D, Mitra D
Department of Ophthalmology, Stanford Medical School, CA, USA.
CLAO J. 1995 Apr;21(2):111-3.
We evaluated quantitative differences in adherence of Acanthamoeba castellanii trophozoites and cysts to new unworn contact lenses as a function of contact lens type and duration of exposure. Daily wear soft (polymacon), disposable soft (etafilcon A), rigid gas permeable (RGP) (siloxane acrylate), and polymethylmethacrylate (PMMA) contact lenses were exposed to 1 x 10(5)/mL log phase A. castellanii (trophozoite:cyst ratio 90:10) for 10 seconds, 30 minutes, 60 minutes, and 120 minutes. The number of adherent organisms was determined by light microscopy and confirmed by scanning electron microscopy. Rates of cyst adherence were similar among contact lens types. We observed significantly greater adherence of trophozoites to RGP and PMMA lenses compared with soft contact lenses (P < 0.05). This difference in trophozoite adherence was significant at all four time periods (P < 0.05). Our findings show that A. castellanii trophozoites and cysts adhere to both soft and rigid contact lens types. We also found that although trophozoite adherence increases as a function of duration of exposure, adherent organisms were observed with exposure times as brief as 10 seconds. This suggests that all contact lens types may be at risk for Acanthamoeba attachment and that even minimal exposure times may be sufficient for lens contamination.
我们评估了卡氏棘阿米巴滋养体和包囊对新的未佩戴过的隐形眼镜的附着情况的定量差异，该差异是隐形眼镜类型和暴露时间的函数。日戴型软性（聚甲基丙烯酸羟乙酯）、一次性软性（甲基丙烯酸羟乙酯）、硬性透气性（RGP）（硅氧烷丙烯酸酯）和聚甲基丙烯酸甲酯（PMMA）隐形眼镜分别暴露于浓度为1×10⁵/mL的对数生长期卡氏棘阿米巴（滋养体:包囊比例为90:10）中10秒、30分钟、60分钟和120分钟。通过光学显微镜确定附着生物的数量，并通过扫描电子显微镜进行确认。不同类型隐形眼镜的包囊附着率相似。我们观察到，与软性隐形眼镜相比，滋养体对RGP和PMMA镜片的附着明显更多（P<0.05）。在所有四个时间段，滋养体附着的这种差异均具有统计学意义（P<0.05）。我们的研究结果表明，卡氏棘阿米巴滋养体和包囊均可附着于软性和硬性隐形眼镜类型。我们还发现，尽管滋养体的附着随着暴露时间的延长而增加，但在暴露时间短至10秒时就观察到了附着生物。这表明所有类型的隐形眼镜都可能有被棘阿米巴附着的风险，并且即使是最短的暴露时间也可能足以污染镜片。
