Optics of the Growing Crystalline Lens

描述(申请人提供)：本项目是应PA-10-009，生物工程研究资助提交的，目的是了解晶体晶体在整个生命周期中的持续生长如何有助于眼睛光学质量的变化。 要检验的主要假设是：(1)随着晶状体生长而发生的晶状体纤维细胞致密引起的晶状体折射率梯度的变化与晶状体屈光度和球差的年龄相关。(2)这些变化是角膜和内眼球差逐渐失去平衡的原因。该方案有三个具体目标：目标1：建立具有折射率梯度的晶体的年龄相关光学模型将发展新的实验方法，利用光学相干层析成像来测量体外晶体的折射率梯度、折射率和像差。一旦得到验证，这些技术将被用于量化体外晶状体的光学参数作为年龄的函数。这些数据将被用来开发理论模型和计算工具，以模拟透镜生长引起的折射率梯度的变化，并预测这些变化如何改变晶体透镜的倍数和像差。目的2：量化晶状体形状和屈光度梯度对活体眼球差的贡献。Aim 1的方法将被扩展到从眼前节的光学相干断层成像图像中恢复体内晶状体的折射率梯度、倍数和球差。将测量活体人类晶状体的光学参数作为年龄的函数，以确定晶状体生长对晶状体球差以及角膜和内部像差之间的平衡的作用。目的3：评价晶状体形状和屈光度梯度对眼周边光学的影响。我们将通过评估晶状体对眼睛周边光学性能的贡献来应用我们的模型。然后，模型透镜将被集成到整个眼睛模型中，该模型将输出放松和调节状态下的周边折射和离轴像差，作为年龄的函数。这些数据将被用来测试晶状体生长和调节变化会导致整个眼睛的周边屈光和离轴像差变化的预测。该项目将从根本上对生理光学领域产生广泛影响。量化透镜度数和像差随年龄的变化将有助于更好地了解屈光不正和像差的发展。通过表征晶状体生长对眼睛像差状态的贡献，这些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，并帮助设计考虑晶状体年龄变化的改进治疗方法，以改善长期视觉结果。 与公共健康相关：眼睛的水晶晶状体在一生中不断生长。这种生长是近视等屈光不正发展的一个因素。它还会改变晶状体的光学质量，这可能会对视力矫正程序的长期结果产生负面影响。该项目的目标是更好地了解晶状体的持续生长如何改变眼睛的光学质量。该项目将有助于更好地了解屈光不正的发展，帮助开发更好的治疗方法来防止屈光不正的发展，并帮助设计改进的视力矫正治疗方法。

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. PUBLIC HEALTH RELEVANCE: The crystalline lens of the eye continuously grows throughout life. This growth is a factor in the development of refractive errors, such as myopia. It also produces changes in the optical quality of the lens which can negatively affect the long-term outcome of vision correction procedures. The goal of the project is to better understand how the continuous growth of the crystalline lens changes the optical quality of the eye. The project will help better understand refractive error development, help develop better treatments to prevent the development of refractive errors, and help design improved vision correction treatments.