Effects of energy drink consumption on retinal and choroidal structures and pupil dynamics: A multimodal ocular imaging study

PURPOSE: To evaluate the effects of energy drink (ED) consumption on choroidal thickness (CT), central macular thickness (CMT), choroidal vascularity index (CVI), retinal microvasculature, pupil diameter (PD), intraocular pressure (IOP), central corneal thickness (CCT), and anterior chamber depth (ACD).
METHODS: Twenty-seven volunteers with no systemic or ocular diseases were enrolled in this prospective study. CT and CVI by optical coherence tomography (OCT), retinal vessel density (VD) by OCT-angiography, and PD by corneal topography were measured before the ED ingestion. Measurements were performed 1 h and 2 h after ED ingestion again. One week later, the measurements were repeated after the participants consumed 250 mL of water.

RESULTS: There was a significant decrease in temporal CT at 1 h after ED intake compared to baseline (p=0.005). Temporal CT was not significantly different from baseline 2 h after ED intake (p=0.763). There was a significant increase in temporal CT at both 1 and 2 h after water intake (0.039 and 0.022, respectively). Subfoveal CT was significantly lower at 1 h after ED intake compared to baseline (p=0.009), whereas no significant difference in subfoveal CT was found at the end of the 2nd h (p=0.076). Water consumption did not affect subfoveal CT (p=0.473). There was no statistically significant difference in IOP, CCT, ACD, PD, CMT, nasal CT, CVI, and retinal VD measured at 1 and 2 h after both ED and water consumption compared to baseline (p>0.05).
CONCLUSION: ED consumption resulted in a transient decrease in CT but did not cause significant alterations in other anterior or posterior ocular parameters, including IOP, PD, or retinal microvasculature. These findings suggest that moderate ED intake may induce short-term vascular changes in the choroid without affecting overall retinal or anterior segment structure in healthy individuals.

Keywords: Choroidal thickness, Choroidal vascularity index, Energy drink, Retinal vessel density