Author: Oleg Kolenko (Russian Federation)
Co-authors: Oleg Kolenko, Evgenii Sorokin, Yaroslav Pashentsev
To investigate retinal blood flow in pregnant women with diabetes mellitus using OCT angiography.
The work was performed in the S.N. Fyodorov NMRC «MNTK «Eye Microsurgery», Khabarovsk, Russia
The study involved 60 pregnant women: 24 with type 1 diabetes and 36 healthy women with a physiological course of pregnancy (control group). The average age of pregnant women with diabetes was 29.1±4.7 years, the average duration of diabetes was 11.1±8.4 years. The average HbA1c value was 6.3±1.5%. In 10 patients no diabetic retinopathy (DR) was detected during pregnancy. 14 pregnant women (58%) were diagnosed with DR. In 5 patients DR was detected during the pregestational period. In 9 patients DR manifested itself during pregnancy. By the third trimester of pregnancy, 6 patients had proliferative DR (PDR), 5 patients had severe nonproliferative DR (NPDR), and 3 had NPDR. All patients with PDR and severe NPDR underwent retinal laser coagulation prior to examination. In the group of healthy pregnant women the average age of the patients was 30±4.2 years. OCT angiography with HD Angio Retina 6.0 mm scanning protocol was performed. Vessel density Whole Image (VDWI), Foveal Vessel density (VDF), area of foveal avascular zone (FAZ) in the superficial retinal plexus were investigated. One random eye was included in the analysis. Pregnant women with diabetes were examined in all three trimesters, healthy pregnant women - in the third trimester.
In pregnant women with diabetes in the third trimester, the mean VDWI values were 50.47±4.45%, VDF - 27.15±8.08%, FAZ - 0.36±0.15 mm2, in the control group – VDWI – 51.93±3.16%, VDF – 34.52±6.32%, FAZ – 0.27±0.1 mm2, respectively. In the third trimester, VDF in pregnant women with diabetes was significantly less than in the control group, in the absence of differences in VDWI and FAZ. This decrease in VDF was not associated with an expansion of FAZ, which may indicate the presence of vascular dysregulation due to chronic impairment of glycemic status, a decrease in perfusion, and the development of an ischemic process - microangiopathy in the fovea zone, even in patients showing no clinical signs of DR. In pregnant women with diabetes without DR in the third trimester, the mean VDWI values were 52.26 ± 3.22%, VDF – 24.37±8.47%, FAZ – 0.30±0.07 mm2, in pregnant women with DR – VDWI – 48.68±4.89%, VDF – 29.93±6.93%, FAZ – 0.43±0.18 mm2, respectively. VDWI was significantly lower, and FAZ was significantly higher in pregnant women with DR than in pregnant women with diabetes mellitus without DR, which is consistent with literature data and characterizes the defeat of the retinal microvasculature. In 11 pregnant women with DR (6 women with PDR, 5 – with severe NPDR), retinal nonperfusion zones were visualized in the posterior pole, the area of which in 6 patients during pregnancy from the 1st trimester to the 3rd trimester tended to expand, which indicated the progression of DR. The average value of the total area of non-perfusion zones in these patients, measured in manual mode, in the first trimester was 1.03 ± 0.07 mm2 (from 0.87 to 1.14 mm2), in the second trimester – 1.88±0,46 mm2 (from 1.10 to 2.60 mm2), in the third trimester – 2.55±0.81 mm2 (from 1.38 to 3.52 mm2). In 2 patients with diabetes and the absence of ophthalmoscopic signs of DR in the third trimester, the OCT-A method also revealed areas of nonperfusion in the posterior pole. We regarded these data as a manifestation of subclinical DR and became the reason for active monitoring of the fundus in these patients. The average VDWI value in pregnant women with diabetes in the first trimester was 52.19±1.7%, VDF 25.76±4.85%, FAZ – 0.33±1.18 mm2, in the second trimester – VDWI 52.32±3.39%, VDF 30.95±8.3%, FAZ 0.36±0.12 mm2, in the third trimester – VDWI 50.47±4.45%, VDF 27.15±8.08%, FAZ 0.4±0.32 mm2. When analyzing the values of VDWI, VDF and FAZ area in pregnant women with diabetes in different trimesters of pregnancy, there were no statistically significant differences. To some extent, the results obtained may be due to a small sample of patients.
1. Pregnant women with diabetes mellitus showed a statistically significant decrease in Foveal Vessel density in the superficial retinal plexus in the third trimester, compared with healthy women with physiological pregnancy, in the absence of significant differences in Vessel density Whole Image and the area of the foveal avascular zone. The data obtained are of practical importance for the diagnosis of the manifestation of diabetic retinopathy during pregnancy. 2. In pregnant women with diabetic retinopathy in the third trimester of pregnancy, a statistically significant expansion of the foveal avascular zone with a decrease in the total vascular density in the superficial plexus was revealed, in comparison with pregnant women with diabetes mellitus without retinopathy. 3. There were no statistically significant differences in the indices of retinal blood flow in the superficial vascular plexus in different trimesters of pregnancy in women with diabetes mellitus. 4. OCT-angiography is a valuable diagnostic method that allows non-invasive diagnostics of the presence of areas of retinal nonperfusion in the absence of ophthalmoscopic signs of diabetic retinopathy in pregnant women with diabetes mellitus, as well as to assess the state of areas of retinal nonperfusion during pregnancy in patients with diabetic retinopathy.