Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA.
Doc Ophthalmol. 2022 Apr;144(2):81-97. doi: 10.1007/s10633-022-09866-y. Epub 2022 Mar 5.
In this study, we assessed several extended electroretinographic protocols using nonstandard stimuli. Our aim was to separate and quantify the contributions of different populations of retinal cells to the overall response, both to assess normal function and characterize dogs with inherited retinal disease.
We investigated three different protocols for measuring the full-field flash electroretinogram-(1) chromatic dark-adapted red and blue flashes, (2) increasing luminance blue-background, (3) flicker with fixed frequency and increasing luminance, and flicker with increasing frequency at a fixed luminance-to assess rod and cone contributions to electroretinograms recorded in phenotypically normal control dogs and dogs lacking rod function.
Temporal separation of the rod- and cone-driven responses is possible in the fully dark-adapted eye using dim red flashes. A- and b-wave amplitudes decrease at different rates with increasing background luminance in control dogs. Flicker responses elicited with extended flicker protocols are well fit with mathematical models in control dogs. Dogs lacking rod function demonstrated larger amplitude dark-adapted compared to light-adapted flicker responses.
Using extended protocols of the full-field electroretinogram provides additional characterization of the health and function of different populations of cells in the normal retina and enables quantifiable comparison between phenotypically normal dogs and those with retinal disease.
在这项研究中，我们使用非标准刺激物评估了几种扩展的视网膜电图方案。我们的目的是分离和量化不同视网膜细胞群体对整体反应的贡献，以评估正常功能和表征遗传性视网膜疾病的犬。
我们研究了三种不同的全视野闪光视网膜电图测量方案：（1）色觉暗适应红和蓝闪光，（2）增加亮度的蓝背景，（3）固定频率的闪烁和增加亮度，以及固定亮度下增加频率的闪烁，以评估表型正常对照犬和缺乏杆状功能的犬的视网膜电图中的杆状和锥状细胞贡献。
使用暗适应的弱红光可以在完全暗适应的眼中实现杆状和锥状驱动反应的时间分离。在对照犬中，随着背景亮度的增加，A 波和 b 波的振幅以不同的速率下降。在对照犬中，使用扩展闪烁方案产生的闪烁反应可以很好地符合数学模型。缺乏杆状功能的犬在暗适应时的闪烁反应幅度比光适应时大。
使用全视野视网膜电图的扩展方案为正常视网膜中不同细胞群体的健康和功能提供了额外的特征描述，并能够对表型正常的犬和患有视网膜疾病的犬进行可量化的比较。
