Olsen T, Sperling S
Exp Eye Res. 1987 Apr;44(4):481-90. doi: 10.1016/s0014-4835(87)80159-8.
The swelling pressure of 115 human corneas was determined using a modified electronic balance modified to simultaneously record the swelling force and the thickness of the stroma. The swelling force was found to follow a straight-line dependence on the stromal thickness when plotted in a double logarithmic scale, which means that the swelling pressure of each cornea could be expressed by a power fit of the form SP = aTb, where SP is swelling pressure, T stromal thickness, and a and b are constants of the cornea. In 45 control corneas swollen in 0.9% NaCl, pH 7.4, 0.01 M Hepes buffer, the mean value (+/- S.D.) of 'a' and 'b' were 7.09 mmHg mm-1 (+/- 2.96) and -3.48 (+/- 0.20), respectively. This corresponded to a mean swelling pressure of 84.0 mmHg at a standard stromal thickness of 0.5 mm. In paired experiments, the swelling pressure was found to be influenced insignificantly (P greater than 0.05) by a number of conditions, including lowering the pH to 4.0, increasing the temperature to 37 degrees C, and increasing the NaCl concentration to 9%. A significant correlation was found between the swelling pressure and the dry weight of the specimen (P less than 0.05), indicating a considerable biological variation of the swelling pressure. It is shown, that this variation may explain the normal variation in human corneal thickness in vivo.
使用经过改良的电子天平测定了115个人类角膜的肿胀压力，该天平经过改装，可同时记录肿胀力和基质厚度。当以双对数标度绘制时，发现肿胀力与基质厚度呈直线相关，这意味着每个角膜的肿胀压力可以用SP = aTb形式的幂拟合来表示，其中SP是肿胀压力，T是基质厚度，a和b是角膜的常数。在45个于pH 7.4的0.9% NaCl、0.01 M Hepes缓冲液中肿胀的对照角膜中，“a”和“b”的平均值（±标准差）分别为7.09 mmHg·mm-1（±2.96）和-3.48（±0.20）。这对应于在标准基质厚度0.5 mm时的平均肿胀压力为84.0 mmHg。在配对实验中，发现肿胀压力受多种条件的影响不显著（P大于0.05），包括将pH降至4.0、将温度升至37℃以及将NaCl浓度升至9%。发现肿胀压力与标本的干重之间存在显著相关性（P小于0.05），表明肿胀压力存在相当大的生物学变异。结果表明，这种变异可能解释了体内人类角膜厚度的正常变异。
