Quantifying intraocular scatter with near diffraction-limited double-pass point spread function.

Junlei Zhao,Yun Dai,Yudong Zhang,Jian Kang,Haoxin Zhao,Fei Xiao

doi:10.1364/boe.7.004595

Abstract

Measurement of the double-pass (DP) point-spread function (PSF) can provide an objective and non-invasive method for estimating intraocular scatter in the human eye. The objective scatter index (OSI), which is calculated from the DP PSF images, is commonly used to quantify intraocular scatter. In this article, we simulated the effect of higher-order ocular aberrations on OSI, and the results showed that higher-order ocular aberrations had a significant influence on OSI. Then we developed an adaptive optics DP PSF measurement system (AO-DPPMS) which was capable of correcting ocular aberrations up to eighth-order radial Zernike modes over a 6.0-mm pupil. Employing this system, we obtained DP PSF images of four subjects at the fovea. OSI values with aberrations corrected up to 2nd, 5th and 8th Zernike order were calculated respectively, from the DP PSF images of the four subjects. The experimental results were consistent with the simulation, suggesting that it is necessary to compensate for the higher-order ocular aberrations for accurate intraocular scatter estimation.

Highlights

It has long been known that the human eye suffers from intraocular scatter that degrades retinal image quality
To validate the simulation results, we developed an adaptive optics (AO) DP point-spread function (PSF) measurement system (AO-DPPMS) with a 145-element PZT deformable mirror, which was capable of correcting ocular aberrations up to eighth-order radial Zernike modes over a 6.0-mm pupil
The results showed that higher-order ocular aberrations had a significant influence on ocular scatter index (OSI) values, suggesting that simulation results were suitable for eyes with significant amounts of scatter in clinical situations

Summary

Introduction

It has long been known that the human eye suffers from intraocular scatter that degrades retinal image quality. OSI is defined as the ratio of the amount of light within an annular area of 12 and 20 arcmin to that recorded within a circular area with a one arcmin radius centered on the central peak of the acquired DP PSF image [9]. This method has been applied for estimating intraocular scatter in cataract eyes [9] and dry eyes [10]

Methods

Results

Discussion

Conclusion