Materials and Methods: Our prospective cross-sectional study was conducted between February 2021 and June 2021. The patient group consisted of 69 children and adolescents aged 7-18 who did not develop DR and vision loss, and the control group comprised 74 age and sex-matched healthy individuals. Foveal avascular zone (FAZ); vascular density (VD) analyses of the superficial capillary plexus (SCP), deep retinal capillary plexus (DCP) and radial peripapillary capillary plexus (RPCP); thickness analyses of the fovea (FT), parafovea (PFT) and peripapillary retinal nerve fiber layer (ppRNFL); were performed using optical coherence tomography angiography (OCTA) . The correlation of the changes detected in the participants with T1DM with the duration of diabetes and glycated hemoglobin (HbA1C) levels were evaluated.

Results: There was no statistically significant difference in FAZ areas, FT, ppRNFL values, DCP VD (except the inferior quadrant) and RPCP VD in children and adolescents with T1DM without clinical retinopathy, but there was a significant reduction in SCP parafoveal VDs and PFT . A high negative correlation was found between parafoveal region VD measurements, HbA1c levels and disease duration in DCP and SCP. In addition, PFT values also negatively correlated with disease duration. A high negative correlation was found between parafoveal region VD measurements, HbA1c levels and disease duration in DCP and SCP. In addition, PFT values were also negatively correlated with disease duration.

Conclusion: Microvascular structural changes may also occur in patients with T1DM without clinical retinopathy. These findings, detectable in OCTA, may be useful for the screening and management of patients with T1DM. Keywords : Children; foveal avascular zone; optic coherence tomography angiography; vessel density; type 1 diabetes mellitus