CLARO (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Spain.
New England College of Optometry, Boston, Massachusetts, United States.
Invest Ophthalmol Vis Sci. 2024 Sep 3;65(11):10. doi: 10.1167/iovs.65.11.10.
To determine the acute effect of caffeine intake on the retinal responses as measured with a global-flash multifocal electroretinogram (gfmERG) protocol at different contrast levels.
Twenty-four young adults (age = 23.3 ± 2.4 years) participated in this placebo-controlled, double-masked, balanced crossover study. On two different days, participants orally ingested caffeine (300 mg) or placebo, and retinal responses were recorded 90 minutes later using a gfmERG at three contrast levels (95%, 50%, and 29%). The amplitude response density and peak time of the direct and induced components (direct component [DC] and induced component [IC], respectively) were extracted for five different eccentricities (1.3°, 5.0°, 9.6°, 15.2°, and 21.9°). Axial length, spherical equivalent refraction, habitual caffeine intake, and body weight were considered as continuous covariates.
Increased IC amplitude response density was found after caffeine ingestion in comparison to placebo (P = 0.021, ƞp2 = 0.23), specifically for the 95% and 50% stimulus contrasts (P = 0.024 and 0.018, respectively). This effect of caffeine on IC amplitude response density was independent of the retinal eccentricity (P = 0.556). Caffeine had no effect on DC amplitude response density or DC and IC peak times.
Our results show that oral caffeine intake increases the inner electro-retinal activity in young adults when viewing stimuli of high- (95%) to medium-contrast (50%). Given the increasing evidence that the inner retinal function is involved in the emmetropization process, these results may suggest that caffeine or its derivatives could potentially play a role in the mechanisms involved in eye growth.
通过不同对比度的全局闪烁多焦视网膜电图（gfmERG）方案，确定咖啡因摄入对视网膜反应的急性影响。
24 名年轻成年人（年龄=23.3±2.4 岁）参加了这项安慰剂对照、双盲、平衡交叉研究。在两天的不同时间，参与者口服摄入咖啡因（300mg）或安慰剂，90 分钟后使用 gfmERG 在三个对比度水平（95%、50%和 29%）记录视网膜反应。提取五个不同偏心度（1.3°、5.0°、9.6°、15.2°和 21.9°）的直接和诱导分量（直接分量[DC]和诱导分量[IC]）的振幅响应密度和峰值时间。眼轴长度、等效球镜屈光度、习惯性咖啡因摄入量和体重被视为连续协变量。
与安慰剂相比，咖啡因摄入后发现 IC 振幅响应密度增加（P=0.021，ƞp2=0.23），特别是在 95%和 50%的刺激对比度下（P=0.024 和 0.018）。咖啡因对 IC 振幅响应密度的这种影响与视网膜偏心度无关（P=0.556）。咖啡因对 DC 振幅响应密度或 DC 和 IC 峰值时间没有影响。
我们的结果表明，口服咖啡因摄入可增加年轻成年人观看高对比度（95%）到中对比度（50%）刺激时的内视网膜电活动。鉴于内视网膜功能参与正视化过程的证据越来越多，这些结果可能表明咖啡因或其衍生物可能在涉及眼球生长的机制中发挥作用。
