Relationship between Size of the Foveal Avascular Zone and Carbohydrate Metabolic Disorders during Pregnancy

AIM: To determine whether the area of the foveal avascular zone (FAZ), as a morphological indicator of the microcirculation of the perifoveal capillary network, changes in the carbohydrate metabolism disorders during pregnancy (the gestational age of patients with gestational diabetes mellitus (GDM) and preexisting diabetes (PexD)). METHODS: Ten normal individuals and 41 eyes of 41 patients, 28 with GDM and 13 with PexD, were studied. A 3 × 3 mm area of the FAZ of the superficial capillary plexus layer (SCP) and the deep capillary plexus layer (DCP) was determined by optical coherence tomography angiography (OCTA; RS-3000 Advance, NIDEK). The significance of the correlation between the size of the FAZ and the weeks of pregnancy was determined. RESULTS: The area of the FAZ of the SCP was 0.38 ± 0.11 mm(2) (normal eyes), 0.41 ± 0.16 mm(2) (GDM), and 0.43 ± 0.10 mm(2) (PexD). The area of the FAZ of the DCP was 0.78 ± 0.23 mm(2) (normal eyes), 0.69 ± 0.16 mm(2) (GDM), and 0.79 ± 0.25 mm(2) (PexD). No significant difference in the FAZ sizes was observed between the groups. The average number of weeks of pregnancy was 24.1 ± 8.2 weeks in the eyes with GDM and 23.3 ± 11.4 weeks in the eyes with PexD (P > 0.05). Significant correlations were found between the size of the FAZ of the SCP and the number of weeks (r = 0.37, P=0.04 for GDM, and r = 0.49, P=0.04 for PexD, Spearman's rank-order correlation coefficient). CONCLUSIONS: For GDM and PexD under established glycemic control, the area of the FAZ is not affected, but vascular changes occurred at the early phase of pregnancy.