Optics of the Growing Crystalline Lens

描述（由申请人提供）：本项目的目的是为了响应PA-10-009，生物工程研究赠款而提交，旨在了解晶体透镜在整个生命周期中的持续生长如何导致眼睛光学质量的变化。 待检验的主要假设为：（1）由于透镜生长时发生的透镜纤维细胞致密化导致的透镜折射率梯度变化与透镜屈光度和球面像差的年龄相关变化相关。(2)这些变化解释了角膜像差和眼内像差之间的逐渐失去平衡。该提案有三个具体的目的：目的1：开发一个年龄相关的光学模型的晶体透镜的折射率梯度将开发新的实验方法来测量的折射率梯度，屈光力和像差的体外透镜使用光学相干断层扫描。一旦确认，这些技术将用于量化体外透镜的光学参数作为年龄的函数。这些数据将用于开发理论模型和计算工具，以模拟由于透镜生长而引起的折射率梯度的变化，并预测这些变化如何修改晶体透镜的屈光度和像差。目的2：定量研究透镜形状和折射率梯度对活体眼球差的影响。目标1的方法将被扩展到从前节的光学相干断层扫描图像中检索体内透镜折射率梯度、屈光度和球面像差。将测量体内人类透镜的光学参数作为年龄的函数，以确定透镜生长对透镜球面像差的作用以及角膜像差和内部像差之间的平衡。目的3：评价透镜形状和折射率梯度对眼睛周边光学的贡献。我们将通过评估晶状体透镜对眼睛周边光学性能的贡献来应用我们的模型。然后将模型透镜集成到整个眼睛模型中，该模型将输出作为年龄的函数的松弛和调节状态下的周边屈光和离轴像差。这些数据将用于检验透镜生长和屈光变化会导致全眼周边屈光和离轴像差变化的预测。该项目将在基础层面上对生理光学领域产生广泛影响。量化透镜屈光力和像差如何随年龄变化将有助于更好地理解屈光不正和像差的发展。通过表征透镜生长对眼像差状态的贡献，结果还将有助于更好地预测像差引导视力矫正手术的长期结果，并有助于设计考虑到透镜中的年龄变化的改进治疗，以改善长期视力结果。

DESCRIPTION (provided by applicant): The objective of this project, submitted in response to PA-10-009, Bioengineering Research Grants, is to understand how the continuous growth of the crystalline lens throughout the life span contributes to changes in the optical quality of the eye. The main hypotheses to be tested are: (1) Changes in the lens refractive index gradient due to the lens fiber cell compaction that occurs with lens growth are correlated with age-related changes in lens power and spherical aberration. (2) These changes account for the progressive loss of balance between corneal and internal ocular aberrations. The proposal has three specific Aims: Aim 1: To develop an age-dependent optical model of the crystalline lens with refractive index gradient New experimental methods will be developed to measure the refractive index gradient, refractive power and aberrations of the in vitro lens using optical coherence tomography. Once validated, these techniques will be used to quantify the optical parameters of the in vitro lens as a function of age. The data will be used to develop theoretical models and computational tools to model the changes in refractive index gradient due to lens growth and predict how these changes modify the power and aberrations of the crystalline lens. Aim 2: To quantify the contribution of the lens shape and refractive index gradient to ocular spherical aberration in vivo. The methods of Aim 1 will be extended to retrieve the in vivo lens index gradient, power, and spherical aberration from optical coherence tomography images of the anterior segment. The optical parameters of the in vivo human lens will be measured as a function of age to determine the role of lens growth on the spherical aberration of the lens and the balance between corneal and internal aberrations. Aim 3: To evaluate the contribution of the lens shape and refractive index gradient to the peripheral optics of the eye. We will apply our model by evaluating the contribution of the crystalline lens to the peripheral optical performance of the eye. The model lens will then be integrated into a whole eye model that will output the peripheral refraction and off-axis aberration in the relaxed and accommodated states, as a function of age. The data will be used to test the prediction that lens growth and accommodative changes produce changes in the peripheral refraction and off axis aberrations of the whole eye. The project will have a broad impact on the field of physiological optics at a fundamental level. Quantifying how lens power and aberrations change with age will help better understand refractive error and aberration development. By characterizing the contribution of lens growth to the ocular aberration state, the results will also help better predict the long-term outcome of aberration-guided vision correction procedures, and help design improved treatments that take into account age-changes in the lens to improve the long-term visual outcome.