The polarity effect of direct current stimulation on the vascular regulation of the inner retina

IF 3 3区医学 Q1 OPHTHALMOLOGY

Acta Ophthalmologica Pub Date : 2025-01-19 DOI:10.1111/aos.17399

Stefanie Freitag, Dietmar Link, Sascha Klee

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引用次数: 0

Abstract

Aims/Purpose: Electrical stimulation is not only a suitable method for researching the human nervous system but also for treating neuronal disorders. In ophthalmology, it is applied to patients suffering from various retinal diseases like retinitis pigmentosa. It is known that in the application of direct current stimulation (DCS), the polarity of the current determines the increase or decrease in neuronal activity and enables different therapeutic approaches. However, the polarisation-dependent effect of the current on the vascular processes in the retina has not yet been investigated. This study examined the effect of anodal and cathodal DCS on the temporal vessels of the inner retina.

Methods: The study was conducted on 24 healthy subjects (14w, 10m, mean age 25.5 ± 3.2yr) who were randomly assigned to either an anodal or a cathodal DCS group (symmetrical design). To test the effect of the DCS (800μA; ring-shaped electrode placed surrounding the eye, square electrode placed at the occiput) on vascular regulation, the DCS was combined with visual flicker stimulation using the Dynamic Vessel Analyzer (DVA, Imedos Systems GmbH; standard protocol). Exclusion criteria were ocular and systemic diseases. We investigated two primary vessel segments (superior temporal artery (STa) and vein (STv)) located between 0.5 and 2.0 disc diameters from the optic disc. For each subject the DVA was performed two times (first baseline DVA1, followed by a 20-minute DCS (different polarity depending on the group), and directly afterwards a second DVA2). For statistical analysis, the t-test for paired samples was used and Bonferroni corrected.

Results: The mean vascular responses (STa/STv) for the anodal DCS group were DVA1: 3.7 ± 1.7%/3.4 ± 1.6%; DVA2: 3.5 ± 1.3%/5.4 ± 3.2% and for the cathodal DCS group DVA1: 3.2 ± 2.0%/4.0 ± 2.6%; DVA2: 3.2 ± 1.4%/2.5 ± 1.3%. For the venous vascular response, we found a significant increase after anodal DCS (p = 0.019) and a significant decrease after cathodal DCS (p = 0.018).

Conclusions: We were able to successfully determine the effect of different DCS polarities on the retinal vascular system. We found significant effects on the veins. The absence of effects on the arteries indicates different regulatory pathways in the retina. This should be investigated by further selective stimulation.

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直流电刺激对视网膜内血管调节的极性效应

目的/目的：电刺激不仅是研究人类神经系统的一种合适的方法，而且是治疗神经疾病的一种合适的方法。在眼科中，应用于各种视网膜疾病，如色素性视网膜炎。众所周知，在直流刺激（DCS）的应用中，电流的极性决定了神经元活动的增加或减少，并使不同的治疗方法成为可能。然而，电流对视网膜血管过程的偏振依赖效应尚未被研究。本研究探讨了阳极和阴极DCS对视网膜内颞血管的影响。方法：健康受试者24例（14岁，10岁，平均年龄25.5±3.2岁），随机分为正负两组（对称设计）。测试DCS (800μA；使用动态血管分析仪（DVA, Imedos Systems GmbH）将DCS与视觉闪烁刺激相结合。标准协议)。排除标准为眼部和全身性疾病。我们研究了两个主要血管段（颞上动脉（STa）和静脉（STv）），它们位于视盘直径0.5和2.0之间。对每个受试者进行两次DVA（第一次基线DVA1，随后是20分钟的DCS（不同极性取决于组），之后直接进行第二次DVA2）。对于统计分析，使用配对样本的t检验并进行Bonferroni校正。结果：阳极DCS组平均血管反应（STa/STv）为DVA1: 3.7±1.7%/3.4±1.6%；DVA2: 3.5±1.3%/5.4±3.2%，阴极DCS组DVA1: 3.2±2.0%/4.0±2.6%；Dva2: 3.2±1.4%/2.5±1.3%。对于静脉血管反应，我们发现阳极DCS后显著增加（p = 0.019），阴极DCS后显著降低（p = 0.018）。结论：我们能够成功地确定不同DCS极性对视网膜血管系统的影响。我们在静脉上发现了明显的效果。对动脉没有影响表明视网膜中有不同的调节途径。这应该通过进一步的选择性刺激来研究。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Acta Ophthalmologica 医学-眼科学

CiteScore

7.60

自引率

5.90%

发文量

433

审稿时长

6 months

期刊介绍： Acta Ophthalmologica is published on behalf of the Acta Ophthalmologica Scandinavica Foundation and is the official scientific publication of the following societies: The Danish Ophthalmological Society, The Finnish Ophthalmological Society, The Icelandic Ophthalmological Society, The Norwegian Ophthalmological Society and The Swedish Ophthalmological Society, and also the European Association for Vision and Eye Research (EVER). Acta Ophthalmologica publishes clinical and experimental original articles, reviews, editorials, educational photo essays (Diagnosis and Therapy in Ophthalmology), case reports and case series, letters to the editor and doctoral theses.