使用蒸气压渗透计对溶液和隐形眼镜进行测量。

Stahl Ulrike, Ho Arthur, Brent Geoffrey, Naduvilath Thomas, Stapleton Fiona

The Vision Cooperative Research Centre, Sydney, Australia.

Optom Vis Sci. 2007 Apr;84(4):321-7. doi: 10.1097/OPX.0b013e318046552f.

PURPOSE

To investigate the influence of sample volume and contact lens material on osmolality measurements made with a Wescor vapor pressure osmometer.

METHODS

Accuracy: Sample volumes of 0.8, 2.0, and 10.0 microL were tested with 290, 320, and 1000 mmol/kg after the osmometer was calibrated with the intended sample volume. Influence of sample volume: Sample volumes ranging from 0.5 to 1.1 microL (0.1 steps) were applied with solutions of 290, 320, 500, and 1000 mmol/kg after the osmometer was calibrated with 0.8 microl, independent of the intended sample volume. Influence of contact lens material: Lens discs of 3.4 millimeters were trephined from the center of Lotrafilcon B, Nelfilcon A, Balafilcon A and Etafilcon A lenses, and equilibrated in phosphate buffered saline with 290 mmol/kg after dehydration for 16 h. The osmometer was calibrated with 0.8 microl and lens discs were inserted into the small sample holder of the osmometer.

RESULTS

There were no significant differences between the nominal and measured osmolalities for each sample volume and solution combination (all p > 0.05). Influence of sample volume: Differences of more than 0.1 microl between the calibration and sample volume significantly affected osmolality readings, with sample volumes larger than calibration volume resulting in lower readings, and smaller volumes resulting in higher readings. Influence of contact lens material: Measured osmolalities of Lotrafilcon B (358.8 +/- 45.4 mmol/kg) and Balafilcon A (356.7 +/- 38.7 mmol/kg) were not significantly different to each other (p = 0.999) but were significantly higher than Etafilcon A (298.2 +/- 15.9 mmol/kg) and Nelfilcon A (281.2 +/- 12.2 mmol/kg, p < 0.05). There was no significant difference between Etafilcon A and Nelfilcon A lenses (p = 0.056). The main factors associated with measured osmolality were water content, sample volume and their interaction (r(2) = 0.716).

CONCLUSION

Osmolality readings varied with calibration and sample volume, and with different contact lens materials.

目的

研究样本体积和隐形眼镜材料对使用Wescor蒸气压渗透压计进行渗透压测量的影响。

方法

准确性：在用预期样本体积校准渗透压计后，分别用290、320和1000 mmol/kg的溶液测试0.8、2.0和10.0微升的样本体积。样本体积的影响：在用0.8微升校准渗透压计后，将0.5至1.1微升（步长为0.1）的样本体积应用于290、320、500和1000 mmol/kg的溶液，与预期样本体积无关。隐形眼镜材料的影响：从Lotrafilcon B、Nelfilcon A、Balafilcon A和Etafilcon A镜片的中心切下直径为3.4毫米的镜片圆盘，脱水16小时后在含290 mmol/kg的磷酸盐缓冲盐水中平衡。用0.8微升校准渗透压计，然后将镜片圆盘插入渗透压计的小样本架中。

结果

对于每种样本体积和溶液组合，标称渗透压与测量渗透压之间均无显著差异（所有p>0.05）。样本体积的影响：校准体积与样本体积之间相差超过0.1微升会显著影响渗透压读数，样本体积大于校准体积会导致读数较低，而样本体积较小则会导致读数较高。隐形眼镜材料的影响：Lotrafilcon B（358.8±45.4 mmol/kg）和Balafilcon A（356.7±38.7 mmol/kg）的测量渗透压彼此之间无显著差异（p = 0.999），但显著高于Etafilcon A（298.2±15.9 mmol/kg）和Nelfilcon A（281.2±12.2 mmol/kg，p<0.05）。Etafilcon A和Nelfilcon A镜片之间无显著差异（p = 0.056）。与测量渗透压相关的主要因素是含水量、样本体积及其相互作用（r² = 0.716）。