ABSTRACT

A previous work has reported a methodology to quantify intraocular scattering using a high sensitivity double-pass instrument with a robust index, the frequency scatter index. The purpose of our study was to evaluate an adaptation of the frequency scatter index for use in clinical double-pass systems. A prospective observational study was carried out in a group of patients with nuclear cataracts (n = 52) and in a control group (n = 11) using conventional double-pass systems. The frequency scatter index and the objective scatter index were used to assess the scattering. The Spearman coefficient was calculated to assess the correlation between both indexes, obtained from the double-pass images. Simultaneous measurements were performed with a double-pass and with a Hartmann-Shack wavefront sensor in the control group. The root-mean-square wavefront error and the full width at half maximum of the double-pass image were used to quantify the residual aberrations introduced by the variations in pupil size and retinal eccentricity. Measurement in eyes with different grades of cataracts shows a strong correlation (ρ = 0.929, p < .0001) between the frequency scatter index and the objective scatter index. A certain degree of correlation was observed between the objective scatter index and the root-mean-square and between the objective scatter index and the full width at half maximum, both for measurements with a different pupillary diameter and with a different retinal eccentricity (p < .05). No relationship was observed between the frequency scatter index and the root-mean-square or between the frequency scatter index and the full width at half maximum (p > .05). We have introduced and evaluated an adaptation of a methodology proposed recently for the measurement of intraocular scattering using the double-pass technique with a robust index, which is less affected by ocular aberrations. The frequency scatter index can be applied to conventional double-pass instruments available in clinical environments.

摘要

先前的一项工作报告了一种使用具有稳健指数（频率散射指数）的高灵敏度双通仪器来量化眼内散射的方法。我们研究的目的是评估频率散射指数在临床双通系统中的适应性。使用传统的双通道系统在一组核性白内障患者 (n = 52) 和对照组 (n = 11) 中进行了一项前瞻性观察研究。频率散射指数和客观散射指数用于评估散射。计算 Spearman 系数以评估从双通道图像获得的两个指标之间的相关性。在对照组中使用双通道和 Hartmann-Shack 波前传感器进行同时测量。双通图像的均方根波前误差和半峰全宽用于量化由瞳孔大小和视网膜偏心率的变化引入的残余像差。对不同级别白内障的眼睛进行测量显示出很强的相关性（ρ = 0.929，p < .0001) 在频率散射指数和客观散射指数之间。对于不同瞳孔直径和不同视网膜偏心率的测量，客观散射指数与均方根之间以及客观散射指数与半峰全宽之间观察到一定程度的相关性（p < .05)。频率散射指数与均方根之间或频率散射指数与半峰全宽之间没有观察到相关性（p> .05)。我们已经介绍并评估了最近提出的一种方法的改编，该方法使用具有稳健指数的双通技术测量眼内散射，该指数受眼像差的影响较小。频率散射指数可应用于临床环境中可用的传统双通仪器。