Measurement of Retinal Foveal Thickness and Foveal Volume during Pregnancy in Saudi Females Using Optical Coherence Tomography

Research Article

Austin J Clin Ophthalmol. 2017; 4(1): 1078.

Measurement of Retinal Foveal Thickness and Foveal Volume during Pregnancy in Saudi Females Using Optical Coherence Tomography

Fahmy R1,2, Almatrafi M1 and Aldarwesh A1*

¹King Saud University, Department of Optometry and Vision Sciences, Riyadh, Saudi Arabia

²Department of Ophthalmology, Faculty of Medicine, Cairo University, Egypt

*Corresponding author: Aldarwesh AQ, Department of Optometry and Visual Sciences, King Saud University, P.O. Box 89885, Riyadh 11692, Saudi Arabia

Received: May 19, 2017; Accepted: June 12, 2017; Published: June 19, 2017


Purpose: To evaluate whether pregnancy have an effect on the foveal thickness (FT) and volume (FV) in Saudi women.

Methods: This study involved 120 pregnant women (age range: 19-37 years) in the first, second and third trimester as the study groups and compared to 40 healthy non-pregnant women with similar age range.The assessment of FT and FV in each group was done using the optical coherence tomography (OCT).Statistics such as the mean, percentiles and range were used. A P-value of 0.05 or less was set to test significance.

Results: Average foveal thickness and foveal volume were significantly larger (P=0.05) in the first, second and third trimesters compared to controls. The mean FT was 226.57±23.3 μm, 231.37±19.21 μm, 240.3±21.76 μmin group 2,3, and 4 respectively compared to control mean of 214.2±19.73μm. Mean FV was 0.259±0.07 mm3, 0.241±0.05 mm3, 0.300±0.11 mm3 in group 2,3, and 4 respectively compared to control mean of 0.169±0.015 mm3. The 3rd trimester was associated with significantly (P=0.05) higher FV compared to the 2nd trimester.

Conclusion: The changes associated with pregnancy such as the increase of body fluids, can cause significant alteration in FT and FV. Although such alteration may not affect the quality of vision in healthy subjects, pregnant women with conditions that may cause fluid retention, or those with pre-existing systemic or eye disease or who are predisposed to risk factors should be monitored during pregnancy to avoid unexpected complications.

Keywords: Foveal thickness; Foveal volume; Pregnancy; Optical coherence tomography


Pregnancy is associated with many physiological and physical changes that are attributed to the shift in hormonal levels, mainly the estrogen and progesterone during the reproductive phases of the first, second and third trimesters. These include gastrointestinal complaints, breast tenderness, fatigue, dizziness, gaining weight, frequent urination and pregnancy mask [1]. Moreover, the estrogen and progesterone were related to somatopsychologic disturbances in pregnancy as early as the first trimester [2,3].

The pregnancy imposes an effect on each organ system of the body, and the eye is no exception. Pregnancy-induced ocular changes include reduction in the intraocular pressure (IOP) [4], unilateral ptosis [5], dry eye [4] and alteration in lens and corneal curvature6,7 have been observed and attributed to fluid and hormonal changes [6- 8].

The ophthalmic changes could start as early as the first trimester and recovery to the pre-pregnancy levels could take weeks to months post-partum [6].

In pregnancy, plasma volume expands to support the uteroplacental blood flow to the fetus. The increase in total body water can be detected early in the pregnancy and continue till the delivery [9]. Pregnancy-induced corneal thickness due to edema has been reported [7]. An alteration in the refractive error and transient loss of accommodation may follow [7]. Fluid retention during pregnancy may affect other ocular tissue such as the choroid, increasing its thickness in the second or third trimesters [10,11]. Subfovealchoroidal areas were also found to be of higher thickness in healthy pregnant subjects [12,13]. Theses changes were detected using optical coherence tomography (OCT) [10-12].

On the other hand, pregnancy may exacerbate retinal diseases such as diabetic retinopathy (DR). Pregnant women with diabetes have a risk of developing either non-proliferative or proliferative DR [14]. One suggestion to the increased risk of DR during pregnancy is the increase in retinal blood flow and hyper-perfusion inducedstress on the compromised retina [15]. It has also been found that progesterone may influence the release of vascular endothelial growth factor (VEGF), a well-known angiogenic factor that exacerbates DR [16]. As the macular edema may develop or worsen during pregnancy, early detection is essential for the management and prevention of further complications.

Clinical examination involves the use of OCT, a non-invasive procedure, which gives high resolution cross-sectional, imaging that, enables the clinician to scan accurately, the subclinical changes in the retina. The measurement of central foveal thickness correlates with the visual acuity and provides a mean of monitoring the macula in different conditions [17]. In this study, we used OCT to quantify foveal thickness and volume in healthy pregnant women during the first, second and third trimesters and to assess whether pregnancyinduced foveal changes contribute to any visual disturbances in healthy subjects.


Study population and examination

All pregnant women were recruited from the gynecology and obstetrics department and ophthalmology unit in King Khalid University between March and May 2014.

This study included 120 healthy pregnant women (120 eyes) and 40 healthy non-pregnant women (40 eyes). Group 1 (control group) included 40 healthy non-pregnant women (40 eyes), Group 2 consisted of 40 healthy pregnant women (40 eyes) in first trimester; group 3 included 40 healthy pregnant women (40 eyes) in the second trimester; and group 4 included 40 healthy pregnant women (40 eyes) in third trimester.

Exclusion criteria for all participants included any history of diabetes mellitus, glaucoma, any corneal and lens pathologies preventing ocular fundus examination, laser therapy, and refractive error greater than 0.50 or less than -0.50 dioptres.

All participants underwent full ophthalmic examination in the form of: visual acuity test using E chart, auto refraction KR.8800, and complete slit-lamp examination of the anterior and posterior segment of the eye.

The values of FT and FV were measured by OCT RTVue model –RT100 (optovueInc, Fremont, CA) after mydriasis with tropicamide drop 1%. Three measurements were taken for the right eye and used for statistical analysis. The 6 macular map was used to evaluate the values of FT and FV. All measurements were carried out by same operator on all subjects.

Statistical analysis

The results were analyzed using Graphpad prism software version 7 (GraphPad Software, Inc., La Jolla, USA) and variables are presented as mean ± SD. D’Agostino & Pearson test was used to assess the normality of the data. One- way analysis of variance (ANOVA) was used to compare datasets. The level of significance was set at P value of 0.05 or less.

Ethical consideration

The protocol of the study was explained to each participant at the time of recruitment and informed consent was obtained according to the Declaration of Helsinki. The research was approved by the research ethical committee at King Khalid University Hospital (KKUH).


The study included 120 eyes of 120 healthy pregnant women. The control group consisted of 40 eyes of 40 healthy non-pregnant women. There was no variation in age between the four groups. The mean age was: 30.4±4.1, 29.1±4.7, 28.03±5.4 and 27.4±4.6 years, in group 1,2,3 and 4 respectively. Table 1 shows the results of mean age, FT, and FV values in all participants.