Yuan R, Yager D, Guethlein M, Oliver G, Kapoor N, Zhong R
State College of Optometry, State University of New York, New York.
Optom Vis Sci. 1993 Nov;70(11):976-81. doi: 10.1097/00006324-199311000-00016.
One of the main purposes of cataract surgery is to reduce the debilitating effects of light scatter by the lens. An important effect of this intraocular forward scatter is to produce a veiling retinal illuminance from a glare source. The retinal contrast of the stimulus is thus reduced, and a quantifiable "disability glare" effect may be measured. A complication is introduced by the fact that intraocular scatter arises from other sources in addition to the lens. All present tests of glare disability fail to eliminate or control for these factors, nor do they control for the light adaptation effect of the glare source. The effects of lens removal may not be predicted accurately by such tests, and patients may report little improvement in visual function after surgery. The goal of this research is to provide the background for developing a method of measuring disability glare due only to light scatter in the lens. Thirty-seven patients with mild to moderate cortical cataracts served as subjects. A disability glare effect (DG) was measured with a Maxwellian-view system that eliminates or controls scatter from the iris, sclera, and retina, and which controls for light-adaptation effects from the glare source. DG with this method showed a significant correlation with objective measures of lens light back scatter. Suggestions were made for improvements in the apparatus and procedures for future clinical studies.
白内障手术的主要目的之一是减轻晶状体光散射带来的不良影响。这种眼内前向散射的一个重要影响是产生来自眩光光源的视网膜光幕照度。因此，刺激的视网膜对比度降低，并且可以测量出可量化的“失能眩光”效应。除晶状体外，眼内散射还源于其他来源，这就带来了一个并发症。目前所有的眩光失能测试都未能消除或控制这些因素，也没有控制眩光光源的光适应效应。通过此类测试可能无法准确预测晶状体摘除的效果，并且患者可能报告术后视觉功能改善甚微。本研究的目的是为开发一种仅测量晶状体光散射导致的失能眩光的方法提供背景。37例轻度至中度皮质性白内障患者作为研究对象。使用麦克斯韦观察系统测量失能眩光效应（DG），该系统可消除或控制来自虹膜、巩膜和视网膜的散射，并控制眩光光源的光适应效应。用这种方法测得的DG与晶状体光后向散射的客观测量值显著相关。针对未来临床研究的仪器和程序改进提出了建议。
