Elevated hyperreflective foci as a novel characteristic in idiopathic epiretinal membrane by optical coherence tomography angiography

Purpose The objective of this study was to analyze hyperreflective foci at the vitreous-retinal interface in cases of idiopathic epiretinal membrane (iERM) using enface-OCT. Methods This study included 47 patients (52 eyes) diagnosed with iERM between January 2020 and July 2023. We observed changes in hyperreflective foci in the macular area at each stage of iERM using OCTA on a 6 mm slab of the VRI. Evaluations included the density and percentage of hyperreflective foci of the epiretinal membrane at each stage, as well as the relationship between hyperreflective foci density and other OCT parameters, such as macular thickness and changes in macular superficial vascular density. Results Statistically significant differences in hyperreflective foci density and percentage were observed across the four stages of patients (p < 0.05). Additionally, statistically significant differences in superficial vascular density were noted among the four stages (p < 0.05). Hyperreflective foci area percentage and density correlated significantly with hyperreflective foci, FAZ area, and FAZ perimeter (p < 0.005). However, no correlation was found between hyperreflective foci density and area percentage with superficial vascular density and superficial perfusion density (p > 0.05). Conclusion Hyperreflective foci were identified in all stages of iERM, with their number and density increasing as the disease progressed.