Elsevier

Japanese Journal of Ophthalmology

Volume 46, Issue 2, March–April 2002, Pages 170-176
Japanese Journal of Ophthalmology

Laboratory investigations
Effects of Caffeine on Microcirculation of the Human Ocular Fundus

https://doi.org/10.1016/S0021-5155(01)00498-1Get rights and content

Abstract

Purpose: To determine the effect of caffeine on microcirculation in the human ocular fundus.

Methods: The microcirculation in the ocular fundus of 10 healthy volunteers (10 eyes) was studied using a laser speckle tissue circulation analyzer. Caffeine or placebo (100 mg) was administered orally in a double-masked manner. Square blur rate (SBR), a quantitative index of blood flow velocity, was measured in a temporal site of the optic nerve head (ONH) free of surface vessels and in a middle site of the choroid-retina between the ONH and macula. Intraocular pressure (IOP), blood pressure (BP), pulse rate (PR), and central critical fusion frequency (CFF) were also measured. These parameters were measured before and for 2 hours after administration. The area under curve (AUC) of SBR was calculated for each area. Ocular perfusion pressure (OPP) was also calculated from BP and IOP.

Results: The time-course of change in SBR value showed much individual difference. Caffeine decreased the AUC of SBR in the ONH (P = .0218) as well as in the choroid-retina (P = .0469) significantly. IOP, mean BP, PR, OPP, and central CFF did not change significantly.

Conclusions: These results suggest that caffeine may increase blood vessel resistance and decrease blood flow in the human ONH and choroid-retina.

Introduction

In addition to intraocular pressure (IOP), ocular blood flow has also recently been shown to play a role in the development and progression of glaucoma.1, 2, 3, 4, 5 Interest is now being focused on how this affects the microcirculation of the optic nerve head (ONH). The recent heightened interest in general health maintenance has also led to a growing interest in the effects of food products such as coffee and tea. Research on the effects of caffeine on blood circulation has demonstrated a decrease in cerebral blood flow.6, 7, 8 Studies of the relationship between caffeine and ocular blood flow have thus far been limited to investigation by blue field entoptoscopy of the effects on macular blood flow.9 There have been no reports concerning caffeine ingestion and its effects on serial changes in ONH microcirculation. Therefore, in the present study, we used the laser speckle method to evaluate the effects of caffeine ingestion on human ocular microcirculation.

Section snippets

Materials and Methods

The subjects in this study were 10 healthy volunteers (10 eyes) without any ophthalmologic disorders (other than simple myopia), and comprised 5 men and 5 women ranging in age from 25 to 44 years (mean ± SD, 30.7 ± 6.4 years). Caffeine ingestion, food and drink of any kind, and exercise were prohibited for 6 hours, 2 hours, and 30 minutes before testing, respectively. The study was conducted in a double-blind manner. All subjects underwent the same experimental procedure.

During the study

Results

Figure 1 shows the relative SBR values (ie, sequential changes in relative SBR values), compared to values obtained before the administration of caffeine or placebo (Figure 1A, in ONH; Figure 1B, in choroid-retina). The relative SBR values in the ONH were lowest from 45 to 60 minutes after administration. The values decreased from the baseline (before administration) by 10% at 45 minutes and by 8% at 60 minutes. Analysis of the data at 60 minutes by paired t-test with Bonferroni's correction

Discussion

Whether patients with glaucoma should consume products containing caffeine is still a matter of debate. Some investigators have shown that caffeine increases IOP, and recommended that it be avoided.17, 18 Other studies have shown that ingestion of as much as 400 mg of caffeine does not raise IOP in normal volunteers.19 Recently, ONH microcirculation, in addition to IOP, has been shown to be a factor in the development of glaucoma. No previous studies have investigated the effects of caffeine on

Acknowledgements

This paper was originally published in Japanese in the Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 2001;105:308–13. It appears here in a modified form after peer review and editing for the Japanese Journal of Ophthalmology.

References (38)

  • T.L. Whitsett et al.

    Cardiovascular effects of coffee and caffeine

    Am J Cardiol

    (1984)
  • P. Smits et al.

    Circulatory effects of coffee in relation to the pharmacokinetics of caffeine

    Am J Cardiol

    (1985)
  • P. Kirkinen et al.

    The effect of caffeine on placental and fetal blood flow in human pregnancy

    Am J Obstet Gynecol

    (1983)
  • V. Marks et al.

    Absorption of caffeine from tea, coffee, and coca cola

    Lancet

    (1973)
  • G. Michelson et al.

    Visual field defect and perfusion of the juxtapapillary retina and the neuroretinal rim area in primary open-angle glaucoma

    Graefes Arch Clin Exp Ophthalmol

    (1998)
  • J.E. Grunwald et al.

    Optic nerve and choroidal circulation in glaucoma

    Invest Ophthalmol Vis Sci

    (1998)
  • R.J. Mathew et al.

    Caffeine and cerebral blood flow

    Br J Psychiatry

    (1983)
  • K. Lotfi et al.

    The acute effect of caffeine on human macular circulation

    Invest Ophthalmol Vis Sci

    (1991)
  • Y. Tamaki et al.

    Non-contact, two-dimensional measurement of tissue circulation in choroid and optic nerve head using laser speckle phenomenon

    Exp Eye Res

    (1995)
  • Cited by (81)

    • Acute Increase in Ocular Microcirculation Blood Flow Upon Cholesterol Removal. The Eyes Are the Window of the Heart

      2023, American Journal of Medicine
      Citation Excerpt :

      Exclusion criteria were: 1) relevant systemic comorbidity such as diabetes mellitus, arterial hypertension, and renal failure, 2) current smoker, and 3) history of previous eye disease, except for uncomplicated cataract surgery performed at least 6 months before enrolment. Subjects were asked to abstain from coffee and tea on the study day because these substances are known to potentially affect ocular blood flow.23 On the study day, participants were scheduled to arrive between 7:30 a.m. and 8 a.m. at the study site, where they underwent an ophthalmic examination including measurement of best corrected visual acuity, biomicroscopy with fundus examination, IOP measurement, and LSCI.

    • The human lens: An antioxidant-dependent tissue revealed by the role of caffeine

      2022, Ageing Research Reviews
      Citation Excerpt :

      In ocular tissues, ARs have been identified in e.g., the cornea, iris, ciliary body, choroid, and retina (Beach et al., 2018; Kvanta et al., 1997; Mitchell et al., 1999; Santiago et al., 2020; Wilhelm et al., 2014). In the eye, it was reported that caffeine led to increased aqueous humor transportation (Kurata et al., 1997), vasoconstriction in retinal vessels (Terai et al., 2012), and a decrease in ocular blood flow (Lotfi and Grunwald, 1991; Okuno et al., 2002). Contrary results were shown for intraocular pressure (Adams and Brubaker, 1990; Kurata et al., 1997; Okimi et al., 1991).

    • Effect of caffeine on superficial retinal vasculature of the macula in high myopes using optical coherence tomography angiography – A pilot study

      2022, Journal of Optometry
      Citation Excerpt :

      Caffeine is an adenosine antagonist present in coffee and other beverages. It has an impact on several ocular indices, including ocular blood flow,1 retinal vessel diameter,2 and ocular accommodation.3 Its effect on intraocular pressure (IOP) has been widely studied.

    View all citing articles on Scopus
    View full text