Short-Term Effects of Dark Chocolate on Choroidal Parameters in Myopic Patients During Near Work

To explore the effects of dark chocolate during relaxation and near work on choroidal thickness and blood flow parameters in myopic patients. Thirty-one myopic subjects were recruited for this self-controlled study. Participants need to complete two experiments. Experiment 1: Subjects first underwent a 10-minute washout process (0 diopter), followed by 20 min of near work (5 diopter). Experiment 2: After consuming 30 grams of dark chocolate 2 h in advance, subjects underwent the washout and near work procedures. Choroidal parameters were measured using swept-source optical coherence tomography angiography (SS-OCT/OCTA). Parameters comprised mean choroidal thickness (ChT), choriocapillaris perfusion area (CCPA), along with choroidal vessel volume (CVV) and three-dimensional choroidal vascularity index (CVI) quantified specifically for large- and middle-sized vessels. After consuming dark chocolate, ChT and CCPA significantly increased during relaxation in individuals with myopia. Both experiments found that the choroidal blood flow decreased significantly after near work, but the ChT decreased significantly only after consumption of dark chocolate. Furthermore, there were significant differences in the changes of CCPA and CVI between the two experiments. After consumption of dark chocolate for two hours, a positive effect on choroidal thickness and blood flow was observed under relaxed condition. No evidence was found that consumption of dark chocolate could inhibit the reduction in choroidal thickness or blood flow during near work.