Research, Development and Innovation Department, VISSUM, Instituto Oftalmologico de Alicante, Alicante, Spain.
Cornea. 2011 Dec;30(12):1353-7. doi: 10.1097/ICO.0b013e31821008d5.
To measure the refractive index (RI) of the human corneal stroma in vivo using an objective Abbé refractometer (VCH-1) and to determine if RI of the stroma is related to age.
The VCH-1 was calibrated against a standard subjective Abbé refractometer using 7 randomly selected turbid semiliquid media. VCH-1 was used to measure RI at the central midstroma immediately after lifting the flap in neophyte patients preselected for laser-assisted in situ keratomileusis. Surgical procedures continued as preplanned after measuring the RI; in binocular cases, measurements were taken from the right eye only. Flaps were created using a mechanical microkeratome.
The VCH-1 was capable of measuring the RIs of all 7 turbid semiliquid media. The average RMS difference between RI estimates according to the VCH-1 and standard subjective Abbé refractometer was 0.003. The mean RI (± SD) of the stroma was 1.369 (± 0.008; range, 1.356-1.390), and the mean age (± SD) of the subjects was 33.7 years (± 8.86; range, 18-56 years). A significant linear correlation was found between age and RI. Least squares regression lines equating RI with age (x, years) was of the form: RI = 1.35711 + 0.00034x (r = +0.383, n = 36, P = 0.011).
RI of the stroma in vivo has a tendency to be increased in older patients when the stroma is resected using a mechanical microkeratome.
使用客观阿贝折射仪（VCH-1）测量活体人眼角膜基质的折射率（RI），并确定基质的 RI 是否与年龄有关。
使用 7 种随机选择的混浊半液体介质对 VCH-1 进行校准，与标准主观阿贝折射仪进行比较。VCH-1 用于测量新接受者患者激光辅助原位角膜磨镶术（LASIK）预先选择的中央基质中间层在掀起瓣后立即的 RI。在测量 RI 后，继续按照预先计划进行手术程序；在双眼病例中，仅从右眼进行测量。使用机械微型角膜刀制作瓣。
VCH-1 能够测量所有 7 种混浊半液体介质的 RI。根据 VCH-1 和标准主观阿贝折射仪估计的 RI 的平均 RMS 差异为 0.003。基质的平均 RI（± SD）为 1.369（± 0.008；范围，1.356-1.390），受试者的平均年龄（± SD）为 33.7 岁（± 8.86；范围，18-56 岁）。发现年龄和 RI 之间存在显著的线性相关性。将 RI 与年龄（x，岁）等同的最小二乘回归线的形式为：RI = 1.35711 + 0.00034x（r = +0.383，n = 36，P = 0.011）。
当使用机械微型角膜刀切除基质时，活体基质的 RI 随着年龄的增长有增加的趋势。
