Dick G L
School of Optometry, University of New South Wales, Sydney, Australia.
Ophthalmic Physiol Opt. 1992 Oct;12(4):443-7.
A new mathematical expression is derived to provide an estimate, alpha x, of the axial length of the human schematic eye. Approximations in the expression are made after considering effects in the Gullstrand-Emsley schematic eye. Parameters required to solve the expression are, for two wavelengths, the refractive indices of the humours, the focal power of the cornea and refractive errors in two states of accommodation. Unlike recognized optical methods, additional intraocular parameters are not required. For emmetropic variants of the Gullstrand-Emsley schematic eye with axial lengths between 19 and 27 mm, alpha x is within 0.06 to 0.26 mm of the actual value. Furthermore, alpha x is essentially independent of variations in the refractive indices of the crystalline lens. However, the estimate of alpha x is critically dependent on the accuracy of values assigned to the parameters. For that reason, the model is considered impractical for clinical application.
推导了一种新的数学表达式，用于估计人眼模型的眼轴长度αx。在考虑了Gullstrand-Emsley眼模型中的各种因素后，对该表达式进行了近似处理。求解该表达式所需的参数，对于两个波长而言，是房水的折射率、角膜的屈光力以及两种调节状态下的屈光不正。与公认的光学方法不同，该方法不需要额外的眼内参数。对于眼轴长度在19至27毫米之间的Gullstrand-Emsley正视眼模型变体，αx与实际值的偏差在0.06至0.26毫米范围内。此外，αx基本上与晶状体折射率的变化无关。然而，αx的估计值严重依赖于所赋予参数值的准确性。因此，该模型被认为在临床应用中不实用。
