Acute Effect of Caffeine on Macular Microcirculation in Healthy Subjects

Abstract

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.

Short-Term Effects of Dark Chocolate on Retinal and Choriocapillaris Perfusion in Young, Healthy Subjects Using Optical Coherence Tomography Angiography

“…The dark chocolate in our study contained 108.5 mg of caffeine, as we used the same product utilized by Grassi et al [37], who performed high-performance liquid chromatography to analyze chocolate. The amount of caffeine in the dark chocolate bars in our study was about half the dose that Karti et al [40] used in their study; therefore, it is possible that the vasodilating effect of flavonoids in chocolate might have been limited by the vasoconstrictor effect of caffeine. It is also important to underline that Karti et al [40] used a 6mm × 6mm macular angiogram of the choriocapillaris layer for analysis, which we did not use due to the poor and un-reliable quality of scans.…”

“…The amount of caffeine in the dark chocolate bars in our study was about half the dose that Karti et al [40] used in their study; therefore, it is possible that the vasodilating effect of flavonoids in chocolate might have been limited by the vasoconstrictor effect of caffeine. It is also important to underline that Karti et al [40] used a 6mm × 6mm macular angiogram of the choriocapillaris layer for analysis, which we did not use due to the poor and un-reliable quality of scans. Furthermore, Karti et al [40] used a choroidal slab with boundaries 31 to 59 µm below the retinal pigmented epithelium, whereas we used a newer OCT-A software version (2017.1.0.151), which yields a slab at −9 µm to 31 µm offset from Bruch's membrane, making results difficult to compare.…”

“…An important consideration, that should be taken into account, is the caffeine content present in dark chocolate. Karti et al [40] found a significantly reduced perfusion in the superficial and the deep retinal plexuses, and also in the choriocapillaris following caffeine consumption. Caffeine could have altered the effect of flavonoids on the retinal and choroidal circulation.…”

“…It is also important to underline that Karti et al [40] used a 6mm × 6mm macular angiogram of the choriocapillaris layer for analysis, which we did not use due to the poor and un-reliable quality of scans. Furthermore, Karti et al [40] used a choroidal slab with boundaries 31 to 59 µm below the retinal pigmented epithelium, whereas we used a newer OCT-A software version (2017.1.0.151), which yields a slab at −9 µm to 31 µm offset from Bruch's membrane, making results difficult to compare.…”

“…The parameters used in this study were whole vessel density and foveal vessel density, which represents the central circular area with a 1 mm radius. The choriocapillaris (CC) flow area was calculated automatically as vessel area of CC divided by total area using a 3 mm × 3 mm macular image of the CC layer with the slab automatically segmented at −9 µm to 31 µm offset from Bruch's membrane [40][41][42]. Figure 2 shows images of the SCP, DCP, and CC.…”