Total macular volume and foveal retinal thickness alterations in healthy pregnant women

Physiological and pathological changes to the eye and vision during and after pregnancy

Pregnancy introduces a multitude of changes in the body, including hormonal fluctuations and metabolic changes, which can lead to atypical ocular signs and symptoms. Ocular manifestations range from fluctuations in vision, to microstructural changes in the retina and choroid, to dry eye disease. This narrative review highlights the range of pregnancy-related effects on the eye and vision that are likely to present in the context of routine eyecare. Specifically, physiological ocular changes and pathological ocular changes that manifest for the first time, or are exacerbated, in uncomplicated pregnancy are discussed. The literature has evolved from simply noting differences in the eye between pregnant and non-pregnant groups, to refining knowledge of the proposed underlying pathophysiology with the advent of newer technologies in eyecare. A particular focus of this review is navigating when pregnancy changes in the eye occur or peak during the gestational period, and whether the changes are short-lived or might extend past pregnancy. While many pregnancy-associated changes are temporary and resolve post-partum, it is also recognised that some changes persist after pregnancy, with a notable absence of literature on ocular changes with loss or termination of pregnancy. Currently or previously pregnant women (or those planning to become pregnant), and other health professionals, should be educated about the importance of seeking eyecare before, during and after pregnancy.

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.

The thickness changes of retina in high myopia patients during the third trimester of pregnancy: a pilot study

Objectives

To observe and compare the difference in retinal thickness using optical coherence tomography (OCT) between patients with high myopia (HM) during the third trimester of pregnancy and age-matched HM non-pregnant women.

Methods

A case-control study. A total of 39 eyes from 39 HM women in the third trimester (study group) and 50 eyes of 50 age-matched non-pregnant women with HM (control group) were included. All subjects underwent SD-OCT examination. The built-in software was used to measure the retinal thickness in macular region. The data from two groups were compared using independent-samples t test.

Results

Among the 89 subjects in this study, the mean gestational age of the study group was 35.09 ± 2.44 weeks, and the average age was 32.24 ± 3.75 years. The average age of the control group was 34.04 ± 7.19 years old. Compared with the control group, the average thickness of parafoveal area, and the average thickness of parafoveal superior, inferior, temporal quadrants of the superficial retina and the average thickness of the foveal and parafoveal of the superficial retina were significantly decreased in the study group (P < 0.05). Compared with the control group, the average thickness of all quadrants of the retina in the parafoveal area except the nasal quadrant were significantly decreased in the study group (P < 0.05).

Conclusions

In this observational study, the retinal thickness of patients with high myopia during the third trimester of pregnancy was thinner than that of non-pregnant women with age-matched high myopia.

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

Background

Retinal capillary is vulnerable to diabetes, whether gestational diabetes mellitus (GDM) eyes without clinical retinopathy have capillary abnormalities has not been well studied. To observe the microvasculature changes in eyes of GDM women compared with normoglycemic pregnant women and non-pregnant women by optical coherence tomography-angiography (OCT-A).

Methods

GDM women, age-matched normoglycemic pregnant women and non-pregnant women were included in this study. All subjects were examined by OCT-A, vascular density and macular foveal parameters were measured automatically.

Results

Thirty eight non-pregnant women (NC group), thirty pregnant women without GDM (PC group), and thirty one GDM women (GDM group) were included in this study. There was a significant reduction of vascular density in superficial capillary layer, but an increase in deep capillary layer in PC and GDM groups (P < 0.001). When in terms of the average vascular density, the difference was insignificant among these three groups. Although all the measurements were similar between PC and GDM groups, more capillary “dropout” changes were detected in GDM group. Unexpectedly, the abnormal changes of central macular thickness thinning and foveal avascular zone enlargement seen during pregnancy were improved when compared to PC group.

Conclusions

The changes of vascular density implied the redistribution of capillary network from superficial to deep layer under pregnancy and GDM states. Although the transient hyperglycemia aggravates the changes of capillary “dropout”, GDM group revealed the improvement of central macular thickness thinning and foveal avascular zone enlargement during pregnancy.

Chorioretinal Alterations Induced by Preeclampsia

Hypertension during pregnancy, which is essentially a microvascular disease that destroys the end-organ microcirculation, should not be underestimated, as it could lead to organ failure in the kidneys, lungs, and brain. Preassessment of the microcirculatory state through systematic observation of the fundus has been proven to be noninvasive and feasible. Although hypertension in preeclampsia patients will resolve after childbirth, the sticking point is determining the best termination moment. Early diagnosis and treatment can prevent long-term ocular complications and cardiovascular risks for pregnant women in the future. In order to adjust the treatment strategy through more sensitive and precise fundus changes, we comprehensively summarized the common structural changes in the fundus in preeclampsia patients, including changes in the blood vessels, choroid, and retina, as well as the application of quantitative observation for chorioretinal alterations in recent years.

To Evaluate Choroidal and Retinal Thicknesses in Singleton versus Twin Pregnancies using Optical Coherence Tomography

PURPOSE:

The purpose of the study was to evaluate the choroidal and retinal thicknesses in singleton versus twin pregnancies.

MATERIALS AND METHODS:

This study included 20 single and 20 twin pregnant women in their 3^rd trimester with 20 age-matched healthy nonpregnant women as a control group. All participants underwent a detailed ocular examination. Cirrus enhanced depth imaging-optical coherence tomography was used for choroidal thickness (CT) with frame enhancement software. The study was divided into three groups: Group 1 – singleton pregnancy, Group 2 – twin pregnancy, and Group 3 – healthy nonpregnant controls. CT was measured from nasal, subfoveal, and temporal fields.

RESULTS:

Regarding CT, the twin pregnancy group had the thickest choroid followed by the singleton pregnancy group and control group. There was a statistically significant difference between Group 2 and Group 3 in terms of nasal, subfoveal, and temporal CTs (P = 0.002, P = 0.001, and P = 0.003, respectively). There was a statistically significant difference between Group 1 and Group 3 regarding just subfoveal CT (P = 0.028). Regarding retinal thickness, there was a statistically significant difference between Group 1 and Group 3 regarding the mean macular volume and ganglion cell-inner plexiform layer thicknesses (P < 0.05). Furthermore, regarding mean retinal nerve fiber layer thickness, there was a statistically significant difference between Group 1 and Group 2 and between Group 2 and Group 3 (P = 0.004, P = 0.003, respectively).

CONCLUSION:

Our study is the first one which evaluates choroidal and retinal thicknesses in twin pregnancies. We found that there was an increase in CT in the 3^rd trimester of pregnancies and it was prominent in twin pregnancies.

Comparison of subfoveal choroidal thickness in healthy pregnancy and pre-eclampsia

PURPOSE

Pregnancy is a known predisposing factor for central serous chorioretinopathy (CSC). Choroidal thickness (CT) increases in patients with CSC. This study was designed to evaluate CT in pregnant women.Patients and methodsThis was a prospective study. Fourteen healthy pregnant women and seven patients with pre-eclampsia were included. Twenty-one normal subjects were also recruited. CT was measured using enhanced-depth imaging optical coherence tomography.

RESULTS

The mean CT of normal subjects, healthy pregnant women and patients with pre-eclampsia were 264.95±21.03, 274.23±29.30 and 389.79±25.13 μm, respectively (normal subjects vs healthy gravidas: P>0.05; normal subjects vs pre-eclampsia: P<0.001; healthy gravidas vs pre-eclampsia: P<0.001). CT decreased from 381.05±22.96 μm to 335.17±9.97 μm 1 week after delivery in patients with pre-eclampsia.

CONCLUSIONS

Pregnancy itself did not increase CT, whereas pre-eclampsia did appear to result in increased CT. This suggests that additional unknown factors induce hyperpermeability in pregnant women.

Assessment of Macular Peripapillary Nerve Fiber Layer and Choroidal Thickness Changes in Pregnant Women with Gestational Diabetes Mellitus, Healthy Pregnant Women, and Healthy Non-Pregnant Women

Background

Gestational diabetes mellitus (GDM) is a risk factor for the development of type II diabetes and it causes maternal and child morbidity. Screening for diabetic retinopathy (DR) is important because patients who develop DR have no symptoms until macular edema and/or proliferative diabetic retinopathy (PDR) are already present. The aim of this study was to determine the early retinal findings of GDM.

Material/Methods

This study was conducted in a tertiary research center. We conducted a prospective cross-sectional study with 3 groups: Group 1 consisted of 36 pregnant women with GDM, Group 2 consisted of 24 healthy pregnant women, and Group 3 consisted of 38 healthy non-pregnant women of reproductive age. Spectralis optical coherence tomography (OCT) was used for the assessment. Macular, choroid, and retinal nerve fiber layer (RNFL) thicknesses were evaluated in patients with GDM and comparisons were made among pregnant women with GDM, healthy pregnant women, and healthy non-pregnant women for these parameters.

Results

The nasal part of the RNFL was significantly thinner in the GDM group than in the healthy pregnant group. None of the patients had retinopathy or macular edema at the time of examination.

Conclusions

Decreased nasal part of RNFL thickness may be the first retinal change in patients with GDM. Our study suggests that OCT should be performed for the patients with GDM for detection of early retinal changes associated with GDM.

Measurement of choroidal thickness and macular thickness during and after pregnancy

AIM

To investigate the effect of pregnancy on subfoveal choroidal thickness (SFCT) and macular thickness in both pregnant and not pregnant healthy women.

METHODS

Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study. Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography (OCT) in the healthy pregnant women (i.e. study group) and healthy women (i.e. control group). OCT measurements were again measured 3mo after delivery in the study group.

RESULTS

Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86±59.18 µm, 387.97±59.91 µm, and 332.40±26.03 µm, respectively. There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group (P=0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group.

CONCLUSION

SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.

Evaluation of the macula, retinal nerve fiber layer and choroid in preeclampsia, healthy pregnant and healthy non-pregnant women using spectral-domain optical coherence tomography

OBJECTIVE

To evaluate the macular, retinal nerve fiber layer (RNFL) and choroidal thickness alterations by using spectral-domain optical coherence tomography (SD-OCT) in preeclampsia and compare with healthy pregnant and healthy non-pregnant controls.

METHOD

The study population included healthy pregnant control group (n: 25), healthy non-pregnant control group (n: 26) and study group with preeclampsia (n: 27). Retinal thickness parameters were measured by SD-OCT.

RESULTS

There was a statistically significant difference among all of the groups for choroidal thickness (p < 0.001). Choroidal thickness in preeclamptic women was significantly thinner than healthy pregnant women. The most thick choroid layer was detected in healthy pregnant group, and also the most thin choroidal thickness was detected in healthy non-pregnant group (p < 0.001). Macular central subfield and foveal center thickness were significantly thinner in preeclamptic study and healthy pregnant groups than healthy non-pregnant group (p < 0.001). However, there was no statistically significant difference between preeclamptic study group and healthy pregnant group for both macular central subfield and foveal center thickness. Average of RNFL thickness was significantly thicker in healthy pregnant group than healthy non-pregnant group (p = 0.004).

CONCLUSIONS

This study revealed that choroidal thickness measured using SD-OCT increased in women with preeclampsia and healthy pregnant women but the increase in choroidal thickness in preeclampsia was lower than the healthy pregnant controls. This lower rise in choroidal thickness can be generally attributed to the markedly increased systemic vascular vasospasm secondary to preeclampsia.