Enlargement of the foveal avascular zone detected by optical coherence tomography angiography in diabetic children without diabetic retinopathy.

Purpose: Evaluation of foveal avascular zone (FAZ) in children with diabetes (DM) using OCTA.

Methods: We examined 112 diabetic children without DR aged 6-18 years and 30 age-matched controls using Topcon OCT Angiography and measured FAZ in superficial (SCP) and deep capillary plexus (DCP). The study group was divided into three subgroups depending on DM duration group 1: < 5 years (n = 40), group 2: 5-10 years (n = 42), group 3: > 10 years (n = 30).

Results: The mean DCP FAZ increased with DM duration from 502.2 μm (SD 137.8) in group 1 to 523.9 μm (SD 159.2) in group 2 and 539.7 μm (SD 189.1) in group 3. Control group differed significantly from group 1 (p = 0.0120), group 2 (p = 0.0019) and group 3 (p = 0.0011). The mean DCP to SCP FAZ surface ratio was 1.88 (SD 0.68) in the study vs 1.58 (SD 0.48) in the control group (p = 0.0232). The DCP and SCP FAZ surface difference was 217.6 μm (SD 100.8 μm) in diabetics vs. 124.2 μm (SD 72.8 μm) in controls (p < 0.0001). In the control group, it was significantly smaller than in group 1 (p < 0.006), group 2 (p < 0.0001) and group 3 (p < 0.0001).

Conclusions: Changes can be detected in FAZ of diabetic children before DR development which can be vital for screening.