Evaluation of retinochoroidal tissues in third trimester pregnants: An optical coherence tomography angiography study

Optical coherence tomography angiography evaluation of retinal and choroidal microvascular changes in pregnant women with a history of unexplained recurrent spontaneous abortions

PURPOSE

To study retinal and choroidal microcirculation by optical coherence tomography angiography (OCTA) in pregnant women with unexplained recurrent spontaneous abortion (RSA) and to compare them with healthy pregnant and nonpregnant subjects.

METHODS

Pregnant women with an unexplained history of RSA (group 1), healthy pregnant (group 2), and healthy non-pregnant women (group 3) were included in the study. After a thorough ophthalmologic examination:best-corrected visual acuity, intraocular pressure,slit-lamp biomicroscopy, fundus examination,autorefractometer, biometry, and axial length measurement; OCT and OCTA measurements were performed with Swept Source OCT-Angiography (Topcon Co, Japan).

RESULTS

The nonpregnant group had higher values for central foveal superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD) and lower values for superior, inferior, and mean VD compared with pregnant groups (p < 0.001). Choriocapillaris values (CC) VD were higher in groups 1 and 2 than in group 3 (p < 0.001). The group with unexplained RSA had a relatively smaller FAZ (foveal avascular zone) area than the group of healthy pregnant women (p:0.047). There were no statistically significant differences between groups in the retina, retinal nerve fiber layer, ganglion cell layer, and choroidal thickness (p > 0.05).

CONCLUSION

Although our study did not identify any etiology in pregnant women with RSA, we observed detectable differences in FAZ area and vessel density values using OCTA, when comparing them with healthy pregnant women and healthy nonpregnant controls. We believe that OCTA, as used in many pathologies such as diabetic and hypertensive retinopathy and retinal vascular occlusion, can also be extended to unexplained RSA both to detect etiology and to monitor treatment in studies with a larger number of patients.

Retinal and choroidal microvascular changes during pregnancy detected with optical coherence tomography angiography: a prospective study

PURPOSE

To investigate choroidal and retinal blood flow and thickness changes using optical coherence tomography and optical coherence tomography angiography during pregnancy.

DESIGN

Prospective and case-control study between June 2020 and June 2021.

METHODS

This prospective study included 41 eyes of 41 pregnant females and 45 eyes of 45 healthy nonpregnant females. Ocular perfusion pressure, retinal thickness, choroidal thickness, foveal avascular zone (FAZ) area, superficial and deep capillary plexuses (SCP and DCP, respectively), vessel density (VD), and choriocapillaris (CC) VD measurements were evaluated with optical coherence tomography and optical coherence tomography angiography.

RESULTS

There was no significant difference in ocular perfusion pressure, retinal thickness, and choroidal thickness during pregnancy. The FAZ area increased as the gestational weeks progressed (p = 0.011). The FAZ area in the first trimester was significantly smaller than that in the control group (p = 0,029). A decrease in the central SCP and DCP VD in the third trimester and an increase in the CC VD during pregnancy were detected (p = 0.01, p < 0.001, and p < 0.001, respectively). We observed an increase in mean VD for both the SCP and DCP in the second trimester (p = 0.02 and p = 0.027, respectively). In the second and third trimesters, the SCP and DCP VD values were found to be significantly higher than in the control group. During the pregnancy, a significant increase in CC VD was detected.

CONCLUSION

This is the first prospective study in the literature that evaluates the measurements in all trimesters of pregnancy with optical coherence tomography angiography. We observed significant retinal and choroidal microvascular changes between trimesters of pregnancy and when compared with healthy females.

IMI-The Dynamic Choroid: New Insights, Challenges, and Potential Significance for Human Myopia

The choroid is the richly vascular layer of the eye located between the sclera and Bruch's membrane. Early studies in animals, as well as more recent studies in humans, have demonstrated that the choroid is a dynamic, multifunctional structure, with its thickness directly and indirectly subject to modulation by a variety of physiologic and visual stimuli. In this review, the anatomy and function of the choroid are summarized and links between the choroid, eye growth regulation, and myopia, as demonstrated in animal models, discussed. Methods for quantifying choroidal thickness in the human eye and associated challenges are described, the literature examining choroidal changes in response to various visual stimuli and refractive error-related differences are summarized, and the potential implications of the latter for myopia are considered. This review also allowed for the reexamination of the hypothesis that short-term changes in choroidal thickness induced by pharmacologic, optical, or environmental stimuli are predictive of future long-term changes in axial elongation, and the speculation that short-term choroidal thickening can be used as a biomarker of treatment efficacy for myopia control therapies, with the general conclusion that current evidence is not sufficient.

Effects of Progesterone and Other Gonadal Hormones on Glutamatergic Circuits in the Retina

BACKGROUND

Gonadal hormones function in the retina; however, their targets have not yet been identified. Therefore, the present study examined the effects of progesterone and other gonadal hormones on glutamatergic circuits in the retina.

METHODS

Extracellular glutamate concentrations, which correspond to the amount of glutamate released, were examined using an enzyme-linked fluorescent assay system. The activity of glutamatergic synapses between bipolar cells and ganglion cells was investigated using a patch clamp technique. Changes in retinal thickness during pregnancy were assessed using optical coherence tomography (OCT) images.

RESULTS

Progesterone and pregnenolone sulfate increased extracellular glutamate concentrations, whereas estrogen and testosterone did not. Progesterone increased the activity of glutamatergic synapses between bipolar cells and ganglion cells. A temporal decrease in the thickness of the peripheral retina was observed in the 1st trimester.

CONCLUSIONS

Progesterone, but not estrogen or testosterone, activated glutamate release in the mouse retina. Increases in the concentration of progesterone during pregnancy did not induce any detectable change in retinal thickness.