Retinal Responses to Simulated Optical Blur Using a Novel Dead Leaves ERG Stimulus.

The purpose of this study was to evaluate retinal responses to different types and magnitudes of simulated optical blur presented at specific retinal eccentricities using naturalistic images. Electroretinograms (ERGs) were recorded from 27 adults using 30-degree dead leaves naturalistic images, digitally blurred with one of three types of optical blur (defocus, astigmatism, and spherical aberrations), and one of three magnitudes (0.1, 0.3, or 0.5 µm) of blur. Digitally computed blur was applied to the entire image, or on an area outside the central 6 degrees or 12 degrees of retinal eccentricity. ERGs were significantly affected by blur type, magnitude, and retinal eccentricity. ERGs were differentially affected by defocus and spherical aberrations; however, astigmatism had no effect on the ERGs. When blur was applied only beyond the central 12 degrees eccentricity, the ERGs were unaffected. However, when blur was applied outside the central 6 degrees, the ERG responses were significantly reduced and were no different from the ERGs recorded with entirely blurred images. Blur type, magnitude, and location all affect the retinal responses. Our data indicate that the retinal area between 6 and 12 degrees eccentricity has the largest effect on the retinal responses to blur. In addition, certain optical blur types appear to have a more detrimental effect on the ERGs than others. These results cannot be solely explained by changes to image contrast and spatial frequency content, suggesting that retinal neurons might be sensitive to spatial cues in order to differentiate between different blur types.

本研究的目的是使用自然图像评估视网膜对在特定视网膜偏心度下呈现的不同类型和程度的模拟光学模糊的反应。 使用30度枯叶自然图像对27名成年人记录视网膜电图（ERG），这些图像通过三种光学模糊类型（离焦、散光和球差）中的一种以及三种模糊程度（0.1、0.3或0.5 µm）中的一种进行数字模糊。数字计算的模糊应用于整个图像，或应用于视网膜偏心度中央6度或12度以外的区域。 视网膜电图受到模糊类型、程度和视网膜偏心度的显著影响。离焦和球差对视网膜电图的影响不同；然而，散光对视网膜电图没有影响。当模糊仅应用于中央12度偏心度以外时，视网膜电图不受影响。然而，当模糊应用于中央6度以外时，视网膜电图反应显著降低，并且与完全模糊图像所记录的视网膜电图没有差异。 模糊类型、程度和位置都会影响视网膜反应。我们的数据表明，在6度到12度偏心度之间的视网膜区域对模糊的视网膜反应影响最大。此外，某些光学模糊类型似乎比其他类型对视网膜电图有更有害的影响。这些结果不能仅仅通过图像对比度和空间频率成分的变化来解释，这表明视网膜神经元可能对空间线索敏感，以便区分不同的模糊类型。