Johnson C A, Samuels S J
Department of Ophthalmology, School of Medicine, University of California, Sacramento 95816, USA.
Invest Ophthalmol Vis Sci. 1997 Feb;38(2):413-25.
To conduct a preliminary evaluation of the efficacy of the frequency-doubling contrast test as a means of screening for glaucomatous visual field loss.
Contrast thresholds for frequency-doubled stimuli were obtained under four test conditions: superior hemifield, inferior hemifield, and central (5 degrees radius) targets using a method of adjustment (MOA); superior hemifield, inferior hemifield, and central targets using a modified binary search (MOBS); four quadrant stimuli and the central target using MOBS; and 16 stimuli (four per quadrant) and the central target using MOBS. One eye each of 36 patients with early (12), moderate (12), and advanced (12) glaucomatous visual field loss was tested, as was one eye each of 36 age-matched normal control subjects.
For hemifield stimuli, the MOBS test procedure had better test-retest reliability, lower individual variation, and greater separation of the normal population and the population with glaucoma than did the MOA procedure. The use of progressively smaller, more localized stimuli produced successively better separation of glaucomatous and age-matched normal control eyes. Area under the Receiver Operating Characteristic curve was 0.81 for hemifield stimuli (sensitivity and specificity, 70% to 75%), 0.91 for quadrant stimuli (sensitivity and specificity, 83% to 85%), and 0.965 for the 16 stimuli (sensitivity 93%, specificity 100%). Test time was approximately 1.3 minutes for hemifields, 1.5 minutes for quadrants, and 5 minutes for the 16 targets.
Preliminary results indicate that the frequency-doubled contrast test provides a quick, efficient means of screening for glaucomatous visual field loss. Test time is relatively short, test-retest reliability is good, and sensitivity and specificity for detection of glaucomatous visual field loss is very good. The use of the MOBS staircase procedure and small, localized stimuli result in the best performance for screening purposes. An expanded normative database and the use of more rapid suprathreshold screening strategies should enhance further the efficacy of this test.
对倍频对比试验作为青光眼视野缺损筛查手段的有效性进行初步评估。
在四种测试条件下获取倍频刺激的对比阈值：使用调整法（MOA）对上方半视野、下方半视野及中央（半径5度）目标进行测试；使用改良二分搜索法（MOBS）对上方半视野、下方半视野及中央目标进行测试；使用MOBS对四个象限刺激及中央目标进行测试；使用MOBS对16个刺激（每个象限4个）及中央目标进行测试。对36例早期（12例）、中度（12例）和晚期（12例）青光眼视野缺损患者的单眼进行测试，同时对36例年龄匹配的正常对照受试者的单眼进行测试。
对于半视野刺激，与MOA程序相比，MOBS测试程序具有更好的重测信度、更低的个体差异，并且在正常人群和青光眼人群之间的区分度更大。使用逐渐变小、更局部化的刺激能使青光眼患者和年龄匹配的正常对照眼之间的区分度越来越好。接受者操作特征曲线下面积对于半视野刺激为0.81（敏感度和特异度为70%至75%），对于象限刺激为0.91（敏感度和特异度为83%至85%），对于16个刺激为0.965（敏感度93%，特异度100%）。半视野测试时间约为1.3分钟，象限测试时间为1.5分钟，16个目标测试时间为5分钟。
初步结果表明，倍频对比试验为青光眼视野缺损筛查提供了一种快速、有效的手段。测试时间相对较短，重测信度良好，检测青光眼视野缺损的敏感度和特异度非常好。使用MOBS阶梯程序和小的、局部化的刺激在筛查目的方面表现最佳。扩大的正常数据库以及使用更快速的超阈值筛查策略应能进一步提高该测试的有效性。
