TASC, Incorporated, Brooks City-Base, Texas, USA.
Invest Ophthalmol Vis Sci. 2011 Sep 22;52(10):7406-15. doi: 10.1167/iovs.10-6699.
One theory of macular pigment's (MP) presence in the fovea is to improve visual performance in glare. This study sought to determine the effect of MP level on three aspects of visual performance in glare: photostress recovery, disability glare, and visual discomfort.
Twenty-six subjects participated in the study. Spatial profiles of MP optical density were assessed with heterochromatic flicker photometry. Glare was delivered via high-bright-white LEDs. For the disability glare and photostress recovery portions of the experiment, the visual task consisted of correct identification of a 1° Gabor patch's orientation. Visual discomfort during the glare presentation was assessed with a visual discomfort rating scale. Pupil diameter was monitored with an infrared (IR) camera.
MP level correlated significantly with all the outcome measures. Higher MP optical densities (MPODs) resulted in faster photostress recovery times (average P < 0.003), lower disability glare contrast thresholds (average P < 0.004), and lower visual discomfort (P = 0.002). Smaller pupil diameter during glare presentation significantly correlated with higher visual discomfort ratings (P = 0.037).
MP correlates with three aspects of visual performance in glare. Unlike previous studies of MP and glare, the present study used free-viewing conditions, in which effects of iris pigmentation and pupil size could be accounted for. The effects described, therefore, can be extended more confidently to real-world, practical visual performance benefits. Greater iris constriction resulted (paradoxically) in greater visual discomfort. This finding may be attributable to the neurobiologic mechanism that mediates the pain elicited by light.
黄斑色素（MP）在中央凹存在的一个理论是改善眩光下的视觉表现。本研究旨在确定 MP 水平对眩光下三个视觉表现方面的影响：光压力恢复、障碍眩光和视觉不适。
26 名受试者参与了这项研究。使用异光谱闪烁光度计评估 MP 光学密度的空间分布。通过高亮度白光 LED 提供眩光。在实验的障碍眩光和光压力恢复部分，视觉任务由正确识别 1° Gabor 补丁的方向组成。在眩光呈现期间，使用视觉不适评分量表评估视觉不适。通过红外（IR）相机监测瞳孔直径。
MP 水平与所有结果测量值显著相关。较高的 MP 光学密度（MPOD）导致更快的光压力恢复时间（平均 P < 0.003）、更低的障碍眩光对比阈值（平均 P < 0.004）和更低的视觉不适（P = 0.002）。在眩光呈现期间较小的瞳孔直径与更高的视觉不适评分显著相关（P = 0.037）。
MP 与眩光下的三个视觉表现方面相关。与以前的 MP 和眩光研究不同，本研究使用自由观察条件，可以解释虹膜色素和瞳孔大小的影响。因此，可以更自信地将描述的效果扩展到现实世界的实际视觉表现益处。更大的虹膜收缩（矛盾地）导致更大的视觉不适。这一发现可能归因于介导光引起的疼痛的神经生物学机制。
