Purpose

To investigate the magnitude and time course of pseudorandom ffERG during light adaptation.

Methods

Ten healthy subjects (26 ± 10.1 years) underwent 20 min of dark adaptation, and then the ffERG was evoked by pseudorandom flash sequences (4 ms per flash, 3 cd.s/m²) driven by m-sequences (2¹⁰–1 stimulus steps) using Veris Science software and a Ganzfeld dome over a constant field of light adaptation (30 cd/m²). The base period of the m-sequence was 50 ms. Each stimulation sequence lasting 40 s was repeated at 0, 5, 10, 15 and 20 min of light adaptation. Relative amplitude and latency (corrected by values found at 0 min) of the three components (N1, P1, and N2) of first-order (K₁) and first slice of the second-order (K_2.1) kernel at 5 time points were evaluated. An exponential model was fitted to the mean amplitude and latency data as a function of the light adaptation duration to estimate the time course (τ) of the light adaptation for each component. Repeated one-way ANOVA followed by Tukey post-test was applied to the amplitude and latency data, considering significant values of p < 0.05.

Results

Regarding the K₁ ffERG, N1 K₁, P1 K₁, and N2 K₁ presented an amplitude increase as a function of the light adaptation (N1 K₁ τ value = 2.66 min ± 4.2; P1 K₁ τ value = 2.69 min ± 2.10; and N2 K₁ τ value = 3.49 min ± 2.96). P1 K₁ and N2 K₁ implicit time changed as a function of the light adaptation duration (P1 K₁ τ value = 3.61 min ± 5.2; N2 K₁ τ value = 3.25 min ± 4.8). N1 K₁ had small implicit time changes during the light adaptation. All the K_2,1 components also had nonsignificant changes in amplitude and implicit time during the light adaptation.

Conclusions

Pseudorandom ffERGs showed different mechanisms of adaptation to retinal light. Our results suggest that K₁ ffERG is generated by retinal mechanisms with intermediate- to long-term light adaptation, while K_2.1 ffERG is generated by retinal mechanism with fast light adaptation course.

中文翻译：

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伪随机全场视网膜电图反映了不同的光适应机制

目的

研究光适应过程中伪随机 ffERG 的幅度和时间过程。

方法

十名健康受试者（26 ± 10.1 岁）经历了 20 分钟的暗适应，然后由 m 序列（^{2 10} –1刺激步骤）使用 Veris Science 软件和 Ganzfeld 圆顶在恒定的光适应场（30 cd/m ²）上。m 序列的基期为 50 ms。在光适应的 0、5、10、15 和 20 分钟重复每个持续 40 秒的刺激序列。_{一阶 (K 1} )的三个分量 (N1、P1 和 N2)和二阶 (K _2.1) 对 5 个时间点的内核进行了评估。将指数模型拟合到平均幅度和延迟数据作为光适应持续时间的函数，以估计每个组件的光适应时间进程 ( τ )。考虑到p  < 0.05的显着值，将重复的单向方差分析和 Tukey 后测应用于幅度和潜伏期数据。

结果

关于 K ₁ ffERG、N1 K ₁、P1 K ₁和 N2 K ₁呈现幅度增加作为光适应的函数（N1 K ₁ τ值 = 2.66 min ± 4.2；P1 K ₁ τ值 = 2.69 min ± 2.10；和 N2 K ₁ τ 值 = 3.49 min ± 2.96)。P1 K ₁和 N2 K ₁隐式时间随光适应持续时间的变化而变化（P1 K ₁ τ值 = 3.61 min ± 5.2；N2 K ₁ τ值 = 3.25 min ± 4.8）。N1 K ₁在光适应过程中有小的隐含时间变化。所有的 K _2,1在光适应过程中，分量的幅度和隐含时间也没有显着变化。

结论

伪随机 ffERGs 显示出对视网膜光的不同适应机制。我们的研究结果表明，K ₁ ffERG 是由具有中长期光适应过程的视网膜机制产生的，而 K _2.1 ffERG 是由具有快速光适应过程的视网膜机制产生的。