To evaluate the acute effects of caffeine on macular microvasculature using quantitative optical coherence tomography angiography analysis.
Fifty-two healthy subjects aged 24 to 48 years were randomly divided into 2 groups: a control group, which received placebo, and a study group, which was subjected to caffeine. All participants underwent optical coherence tomography angiography at baseline and 1 hour after 200-mg oral caffeine intake in the study group and after oral placebo in the control group. Macular flow area, macular vessel density, and foveal avascular zone (FAZ) area were analyzed in both the groups.
The study group consisted of 14 men and 12 women with a mean age of 40.6 ± 8.9 years. The mean age of control group was 39.5 ± 9.4 years, which consisted of 13 men and 13 women. Baseline macular flow area, vessel density, and FAZ area measurements of the study and control groups showed no significant difference (P > 0.05). Oral caffeine intake caused a significant reduction in macular flow area (superficial, deep, and choriocapillaris) and vessel density (P < 0.05). However, there was no statistically significant difference in FAZ area after caffeine intake when compared with baseline measurements (P = 0.063).
We found a significant decrease in macular flow area (superficial, deep, and choriocapillaris) and vessel density after caffeine intake. Our findings are consistent with previous studies using other techniques. We believe that the results of this preliminary study will be useful in future studies about this topic.
The purpose of this study was to evaluate the acute effect of caffeine on macular microcirculation as measured using optical coherence tomography angiography in healthy subjects. The authors’ randomized placebo-controlled study has demonstrated, for the first time, that caffeine causes decrease in retinal and choriocapillaris microcirculation in healthy subjects. The findings of this preliminary study may be of clinical importance.
*Department of Ophthalmology, İzmir Katip Çelebi University Medical Faculty, Izmir, Turkey; and
†Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey.
Reprint requests: Omer Karti, MD, Department of Ophthalmology, İzmir Katip Çelebi University Medical Faculty, Saim Cikrikci Caddesi No: 59, Bozyaka, İzmir, Turkey; e-mail: firstname.lastname@example.org
None of the authors has any financial/conflicting interests to disclose.
O. Karti and M. O. Zengin; acquisition of data: O. Karti; analysis and interpretation of data: O. Karti, M. O. Zengin, Z. Ayhan, S. G. Kerci, and T. Kusbeci; article drafting and revising: O. Karti and M. O. Zengin; final approval: O. Karti, M. O. Zengin, and T. Kusbeci.
Patient consent: Obtained.
The study protocol was approved by Bozyaka Training and Research Hospital Institutional Review Board and Ethics Committee, and the research adhered to the tenets of the Declaration of Helsinki.