ABSTRACT

Purpose

Previous studies indicated that advanced age-related macular degeneration (AMD) affects contrast sensitivity (CS) in humans. The CS results for early/intermediate AMD patients are contradictory. The purpose of this study was to determine if CS testing discriminates early/intermediate AMD patients with normal acuity from normal patients.

Methods

Forty-nine subjects (25 control and 24 early/intermediate AMD patients) were chosen for this project. The age (p = .16) and acuity (p = .34) was not significantly different between the groups. The average simplified AREDS AMD grade for the AMD patients was 2.75 ± 1.03. Three CS functions employing a descending method of limits were measured at the fovea (1. stationary stimulus and, 2. 16 Hz counter-phase stimulus under photopic conditions and 3. the stationary stimulus viewed through a 2 log unit neutral density filter (mesopic condition, background luminance of 1 cd/m²)) and at 4 deg right or left of the fovea with a horizontally oriented sine wave grating (5 deg diameter) viewed on a VPixx monitor (luminance of 100 cd/m²).

Results

The early AMD patients were no different from the control patients for any test condition. The intermediate AMD patients were significantly different from the control patients for the mesopic CS function (p = .05). Post-hoc 2-sample t-tests for the intermediate AMD patients were significantly different from the control patients under the stationary photopic and mesopic conditions for the 1.5 cycle per degree stimulus.

Conclusions

Group differences in CS were only found in intermediate AMD patients. The loss in CS increased for the intermediate AMD patients under low light levels. Thus, CS may not be the optimal test to discriminate early AMD from control patients so other tests measured under dark adapted conditions should be investigated.

中文翻译：

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早期至中期年龄相关性黄斑变性 (AMD) 的对比敏感度

摘要

目的

先前的研究表明，晚期年龄相关性黄斑变性 (AMD) 会影响人类的对比敏感度 (CS)。早期/中期 AMD 患者的 CS 结果是矛盾的。本研究的目的是确定 CS 测试是否能区分视力正常的早期/中期 AMD 患者与正常患者。

方法

为该项目选择了 49 名受试者（25 名对照和 24 名早期/中期 AMD 患者）。年龄 ( p = .16) 和视力 ( p = .34) 在各组之间没有显着差异。AMD 患者的平均简化 AREDS AMD 分级为 2.75 ± 1.03。在中央凹处测量了三个采用极限递减法的 CS 函数（1. 静止刺激和 2. 明视条件下的 16 Hz 反相刺激和 3. 通过 2 log 单位中性密度过滤器观察到的静止刺激（中视条件） , 背景亮度为 1 cd/m ² ))，在中央凹右侧或左侧 4 度处，在 VPixx 监视器上观察到水平方向的正弦波光栅（直径 5 度）（亮度为 100 cd/m ²）。

结果

对于任何测试条件，早期 AMD 患者与对照患者没有什么不同。中间 AMD 患者的中视 CS 功能与对照患者显着不同 ( p = .05)。在 1.5 周期每度刺激的静止明视和中视条件下，中间 AMD 患者的事后 2 样本 t 检验与对照患者显着不同。

结论

CS 的组间差异仅在中度 AMD 患者中发现。在低光照水平下，中等 AMD 患者的 CS 损失增加。因此，CS 可能不是区分早期 AMD 与对照患者的最佳测试，因此应研究在黑暗适应条件下测量的其他测试。