PURPOSE: This research aimed to assess the choroidal alterations in a substantial cohort of diabetes patients, at various phases, using swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA).
METHODS: Between January 2022 and January 2023, people with type II diabetes who had not yet started treatment were chosen at Tanta University Hospitals. Fundus Fluorescein angiography (FFA) was used to grade the stage of diabetic retinopathy (DR). We used the swept source OCT to get high-definition scans of the retina and choroid. We also got thickness (CT) maps of the retina and choroid and volume (CV) maps of the choroid. We used OCTA to find the vessel density index (VDI) at the retinal and choroidal levels. We used multivariate linear regression models to investigate into how severe DR was linked to CT and volume, as well as VDI.
RESULTS: The final analysis comprised 100 subjects, which were categorized into the following four groups: controls, diabetics without DR, non-proliferative DR, and proliferative DR (PDR). Patients with PDR had substantially thinner CT (p < 0.001), lower CV (p < 0.001), and lower VDI (p < 0.001) than the other groups, after adjusting for other variables. A significant correlation was observed between higher average CT and improved best corrected visual acuity(BCVA).
CONCLUSIONS: As DR progressed, CT and CV declined. VDI declined as DR advanced. As the disease worsened, the FAZ rose. These results add to the increasing evidence that changes to the choroid plexus contribute to the development of DR.