Optical Coherence Tomography Angiography Evaluation of Retinochoroidal Microvascular Circulation Differences in Pregnant Women with Pregestational and Gestational Diabetes Mellitus.

Purpose: In this study, the changes in microvascular circulation caused by pregestational and gestational diabetes were observed, without focusing on retinal findings, to reveal the effect of diabetes regulation.

Methods: A total of 135 subjects were included: 30 with gestational diabetes (GDM), 30 pregestational diabetes (PGDM), 30 healthy pregnant normoglycemic subjects, and 45 healthy non-pregnant subjects. All subjects were examined by optical coherence tomography (OCT) and angiography. The retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), choroidal thickness (CT), superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC), vascular density (VD), and foveal avascular zone (FAZ) areas were measured.

Results: The foveal VD of SCP and DCP was significantly lower in the PGDM and GDM groups compared to the control groups (p:0.006 and p:0.001, respectively). CC VD was significantly higher in all pregnant groups compared to non-pregnant controls (p<0.001). The choroidal thickness values were highest in the healthy pregnant group and lowest in the PGDM group. There was no significant difference in FAZ area, retina, RNFL and GCL thickness between the groups. In the PGDM group, a negative correlation was observed between the FAZ area and the HbA1c level (r:- 0.417, p:0.043).

Conclusion: There was a decrease in vascular density in pregnant women with diabetes compared to healthy pregnant women and controls. In the pregnant group with PGDM, a narrowing of the FAZ area was observed with increasing worsening of diabetes control. Diabetes type and glycemic control could influence the microvascular changes even in the absence of clinical or retinal findings.