Dimitrov Peter N, Guymer Robyn H, Zele Andrew J, Anderson Andrew J, Vingrys Algis J
Centre for Eye Research Australia, Department of Ophthalmology, The University of Melbourne, East Melbourne, Victoria, Australia.
Invest Ophthalmol Vis Sci. 2008 Jan;49(1):55-65. doi: 10.1167/iovs.06-1048.
A cathode-ray-tube (CRT) monitor-based technique was used to isolate clinically significant components of dark adaptation. The utility of the technique in identifying adaptation abnormalities in eyes with age-related maculopathy (ARM) is described.
A CRT dark adaptometer was developed to assess cone and rod recovery after photopigment bleach. The following measures were obtained: cone recovery rate (R(c); in decades per minute) and absolute threshold (Tf(c); log candelas per square meter), rod recovery rate (R(r); decades per minute), and rod-cone transition (rod-cone break [RCB], in minutes). These components were isolated by appropriately selecting stimulus size, stimulus location, pigment bleach, and test duration and by coupling the CRT with judiciously selected neutral-density (ND) filters. The protocol was developed by using 5 young observers and was tested on 27 subjects with ARM in the study eye and 22 age-matched control subjects.
The parameters necessary for effective isolation of cone and early phase rod dark adaptation were a 2.6 ND filter (for a standard CRT monitor, 0.08-80 cd . m(-2) luminance output); a 4 degrees foveated, 200-ms, achromatic spot; approximately 30% pigment bleaching; and a 30-minute test duration. These settings returned obvious rod and cone recovery curves in control and ARM eyes that were compatible with conventional test methods and identified 93% of participants with ARM as having delayed dynamics in at least one of the parameters. Cone recovery dynamics were significantly slower in the ARM group when compared with age-matched control subjects (R(c), 0.99 +/- 0.35 vs. 2.63 +/- 0.61 decades . min(-1), P < 0.0001). Three of the 27 eyes with ARM did not achieve RCB during the allowed duration (30 minutes). The remaining eyes with ARM (n = 24) exhibited a significant delay in rod recovery (R(r)(,) ARM, 0.16 +/- 0.03 vs. controls, 0.22 +/- 0.02 decades . min(-1), P < 0.0001) and the average time to RCB (+/-SD) in the ARM group was significantly longer than in the control subjects (19.12 +/- 5.17 minutes vs. 10.40 +/- 2.49 minutes, P < 0.0001).
The CRT dark-adaptation technique described in this article is an effective test for identifying abnormalities in cone and rod recovery. Slowed cone and rod recovery and a delayed RCB were evident in the eyes with ARM. The test method is potentially useful for clinical intervention trials in which ARM progression is monitored.
采用基于阴极射线管（CRT）显示器的技术来分离暗适应的临床显著成分。描述了该技术在识别年龄相关性黄斑病变（ARM）患者眼部适应异常方面的效用。
开发了一种CRT暗适应计，用于评估光色素漂白后视锥细胞和视杆细胞的恢复情况。获得了以下测量值：视锥细胞恢复率（R(c)；每分钟对数单位）和绝对阈值（Tf(c)；每平方米对数坎德拉）、视杆细胞恢复率（R(r)；每分钟对数单位）以及视杆 - 视锥细胞转换（视杆 - 视锥细胞转折点[RCB]，以分钟为单位）。通过适当选择刺激大小、刺激位置、色素漂白程度和测试持续时间，并将CRT与精心挑选的中性密度（ND）滤光片相结合，分离出这些成分。该方案由5名年轻观察者制定，并在27名研究眼中患有ARM的受试者和22名年龄匹配的对照受试者身上进行了测试。
有效分离视锥细胞和早期视杆细胞暗适应所需的参数为：一个2.6的ND滤光片（对于标准CRT显示器，亮度输出为0.08 - 80 cd·m(-2)）；一个4度中心凹、200毫秒的消色差光斑；约30%的色素漂白；以及30分钟的测试持续时间。这些设置在对照眼和ARM眼中均得到了明显的视杆细胞和视锥细胞恢复曲线，与传统测试方法相符，并确定93%的ARM参与者至少在一个参数上存在动力学延迟。与年龄匹配的对照受试者相比，ARM组的视锥细胞恢复动力学明显更慢（R(c)，0.99±0.35对2.63±0.61对数单位·min(-1)，P < 0.0001）。27只患有ARM的眼中有3只在允许的持续时间（30分钟）内未达到RCB。其余患有ARM的眼（n = 24）视杆细胞恢复明显延迟（R(r)，ARM组为0.16±0.03，对照组为0.22±0.02对数单位·min(-1)，P < 0.0001），ARM组达到RCB的平均时间（±标准差）明显长于对照受试者（19.12±5.17分钟对10.40±2.49分钟，P < 0.0001）。
本文所述的CRT暗适应技术是一种识别视锥细胞和视杆细胞恢复异常的有效测试方法。患有ARM的眼中视锥细胞和视杆细胞恢复减慢以及RCB延迟明显。该测试方法对于监测ARM进展的临床干预试验可能有用。
