Macular vascular changes in pregnant women with gestational diabetes mellitus by optical coherence tomography angiography

Optical coherence tomography angiography analysis methods: a systematic review and meta-analysis

Optical coherence tomography angiography (OCTA) is widely used for non-invasive retinal vascular imaging, but the OCTA methods used to assess retinal perfusion vary. We evaluated the different methods used to assess retinal perfusion between OCTA studies. MEDLINE and Embase were searched from 2014 to August 2021. We included prospective studies including ≥ 50 participants using OCTA to assess retinal perfusion in either global retinal or systemic disorders. Risk of bias was assessed using the National Institute of Health quality assessment tool for observational cohort and cross-sectional studies. Heterogeneity of data was assessed by Q statistics, Chi-square test, and I2 index. Of the 5974 studies identified, 191 studies were included in this evaluation. The selected studies employed seven OCTA devices, six macula volume dimensions, four macula subregions, nine perfusion analyses, and five vessel layer definitions, totalling 197 distinct methods of assessing macula perfusion and over 7000 possible combinations. Meta-analysis was performed on 88 studies reporting vessel density and foveal avascular zone area, showing lower retinal perfusion in patients with diabetes mellitus than in healthy controls, but with high heterogeneity. Heterogeneity was lowest and reported vascular effects strongest in superficial capillary plexus assessments. Systematic review of OCTA studies revealed massive heterogeneity in the methods employed to assess retinal perfusion, supporting calls for standardisation of methodology.

Investigation of the effects of gestational diabetes and hypertension on retinal and choroidal microvascular circulation using swept-source optical coherence tomography angiography

PURPOSE

The aim of this study was to investigate the microvascular changes in the retina and choroid in gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH) and to compare the results with those of healthy pregnant subjects.

METHODS

Twenty-nine pregnant subjects with coexisting GDM and PIH (group 1) and 36 healthy pregnant subjects (group 2) were enrolled in the study. All subjects were examined by optical coherence tomography (OCT) and angiography (OCTA). 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) were measured.

RESULTS

We observed that the values of CT and VD were lower in group 1 than in group 2. No significant difference was found between groups in RT, FAZ area and CC VD. SCP and DCP VD values were higher in group 2 in all quadrants. We observed a significant increase in FAZ area and CC VD with increasing systolic blood pressure. No correlation was observed between diastolic blood pressure and FBS with other parameters. In group 1, FAZ area was significantly higher in the diet-treated group than in the insulin-treated group.

CONCLUSION

Monitoring and treatment of pregnant women with PIH and GDM is important because of the risks that may occur during pregnancy. We believe that changes in microvascular circulation can be detected noninvasively with OCTA, even in the absence of clinical or retinal findings.

Diabetic retinopathy in pregnancy - A review

Diabetes and gestational diabetes (GD) are areas of concern worldwide. GD can eventually lead to serious development of diabetic retinopathy (DR) during pregnancy or worsening of an already existing DR. GD confers future risk of diabetes, both in the mother and fetus, further complicating their lives. DR in pregnant women has been intriguing in terms of understanding the prevalence, assessing risk factors causing pathogenesis, and problems associated with treating them. Pregnancy itself is a risk factor for progression of DR. Physiological changes such as metabolic, vascular, immunologic, and hormonal changes that occur during pregnancy can cause development as well as worsening of DR. This can eventually lead to permanent visual loss if not addressed on time. Timing of laser, choice of treatment for diabetic macular edema with laser, intravitreal anti-vascular endothelial growth factor agents (VEGF), and intravitreal steroids pose a serious challenge in managing these patients without causing damage to the mother and fetus. This review article showcases the prevalence, risk factors, and pathogenesis, outlines the management of DR in pregnancy, and recommends guidelines based on the available evidence. PubMed and MEDLINE searches were performed pertaining to the prevalence of GD in India, DR in pregnancy, risk factors for progression of DR, role of vasoactive mediators in DR, role of angiopoietic factors in DR, hormonal influence of DR, role of growth factors in DR, use of fluorescein and indocyanine green angiography, retinal lasers, anti-VEGF agents, intravitreal steroids, anesthesia, and retinal surgery, all pertaining to pregnancy and guidelines and recommendations for managing DR in pregnancy.