Technical University of Catalonia, Department of Optics and Optometry, C∕ Violinista Vellsolà, 37, 08222 Terrassa, Barcelona, Spain.
J Biomed Opt. 2011 Jan-Feb;16(1):016010. doi: 10.1117/1.3528619.
Despite the interest in developing improved formulas for intraocular lens power calculation, there are several sources of uncertainty that may well give rise to a significant residual refractive error. Those concerning the estimation of the corneal power are reviewed. In addition, we explore the possibility of introducing changes in some unconventional parameters of the eye to compensate for defocus and illustrate their effectiveness in two cases: a natural eye and an eye that has undergone previous surgical actions (anterior refractive surgery and cataract surgery with an intraocular lens implant). The results show that changes in the refractive index, thickness, or posterior radius of the cornea have relatively little effect on the overall refractive error. However, small changes in the refractive indexes of the aqueous or the vitreous humors are highly effective, much more so than a similar amount of change in the anterior curvature of the cornea. This fact opens new and attractive possibilities to compensate for refractive error through the introduction of changes in degrees of freedom so far considered unconventional.
尽管人们有兴趣开发改进的眼内人工晶状体屈光力计算公式，但仍有几个可能导致显著剩余屈光误差的不确定来源。本文回顾了角膜屈光力估计方面的不确定性来源。此外，我们还探讨了引入眼睛某些非常规参数变化以补偿离焦的可能性，并通过两个案例说明了其有效性：自然眼和先前接受过手术（前屈光手术和白内障超声乳化吸除联合人工晶状体植入术）的眼。结果表明，角膜折射率、厚度或后表面半径的变化对整体屈光误差的影响相对较小。然而，房水或玻璃体折射率的微小变化非常有效，比角膜前表面曲率类似程度的变化效果更好。这一事实为通过引入迄今为止被认为是非传统的自由度变化来补偿屈光不正提供了新的、有吸引力的可能性。
