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BJO Online First, published on February 20, 2015 as 10.1136/bjophthalmol-2014-306343 Clinical science
Changes in choroidal thickness during pregnancy detected by enhanced depth imaging optical coherence tomography Zeynep Dadaci,1 Husnu Alptekin,2 Nursen Oncel Acir,1 Mehmet Borazan1 1
Department of Ophthalmology, Mevlana University School of Medicine, Konya, Turkey 2 Department of Obstetrics and Gynecology, Mevlana University School of Medicine, Konya, Turkey Correspondence to Dr Zeynep Dadaci, Department of Ophthalmology, Mevlana University School of Medicine, Aksinne M., Esmetas S., No: 16, Meram, Konya 42040, Turkey; [email protected] Received 3 November 2014 Revised 28 December 2014 Accepted 5 February 2015
ABSTRACT Aim To compare the choroidal thickness measurements of healthy pregnant women obtained in the first trimester with measurements obtained in the third trimester using enhanced depth imaging optical coherence tomography (OCT). Methods 54 eyes of 27 healthy pregnant women and 50 eyes of 25 age matched healthy women were enrolled in this observational, cross-sectional study. The pregnant women underwent two OCT scans, one in the first trimester at gestational weeks 6–8, and the other during the third trimester at gestational weeks 32–37; the control group had OCT scanning during the follicular phase of the menstrual cycle, using the enhanced depth imaging mode. Choroidal thicknesses were measured at the fovea, at three locations nasal, and at three locations temporal to the fovea at 500 μm intervals. Results The choroidal thickness measurements obtained in the third trimester were significantly decreased in all measured points in both eyes compared to the measurements obtained in the first trimester ( p0.05). Conclusions Choroidal thickness was found to be significantly decreased in healthy pregnant women during the third trimester compared to the first trimester. This finding can provide valuable information when interpreting pregnancy related ocular disorders.
INTRODUCTION
To cite: Dadaci Z, Alptekin H, Oncel Acir N, et al. Br J Ophthalmol Published Online First: [please include Day Month Year] doi:10.1136/ bjophthalmol-2014-306343
Women’s physiology changes markedly during normal pregnancy. The most distinct alterations occur in the hormonal and cardiovascular systems. There is a dramatic increase in the concentrations of both oestradiol and progesterone.1 Oestradiol is known to induce nitric oxide synthases and increased concentrations of nitric oxide, which is a potent vasodilator, lead to a decrease vascular tone both in the luteal phase of the menstrual cycle and in pregnancy.2 Blood volume starts to increase in the first gestational weeks and reaches a peak in the third trimester. Consequently, peripheral vascular resistance decreases throughout the pregnancy, preventing a rise in the mean arterial blood pressure (MAP).1 The blood flow is redistributed and the
perfusion of certain organs, such as the uterus, breasts, and kidneys, increases.3 Besides the normal physiological adaptations, pregnancy is also a period of various pathologies, some of which are unique to pregnancy. From an ophthalmological point of view, various ocular conditions may occur uniquely during pregnancy and some ocular diseases, such as diabetic retinopathy, may worsen.4 Previous studies have reported increased central corneal thickness,5 changes in corneal curvature, and intraocular pressure (IOP)6 during pregnancy. Pre-eclampsia or eclampsia associated retinopathy and amniotic fluid embolism are unique to pregnancy.4 Also, it is known that pregnancy is a major risk factor for some ocular pathologies such as central serous chorioretinopathy (CSC).7 Choroid is the vascular structure of the eye supplying blood to vital ocular structures. It has some unique characteristics; in contrast to the retina, autoregulation of the blood flow is limited in the choroid and it has intense autonomic innervation.8 Also, increased sympathetic activity and decreased parasympathetic activity occurs in patients with CSC,9 which is one of the most common ocular pathologies encountered in pregnant women. The choroid can also change its thickness to compensate for various ocular conditions, as in response to retinal defocus,10 and its thickness is reported to change in various ocular pathologies, such as central retinal vein occlusion and CSC.11 12 The enhanced depth mode of optical coherence tomography (OCT) allows us to investigate the changes in the choroidal layer of the eye in vivo. Using this method, high resolution cross sectional images of the posterior segment of the eye can be obtained. In particular, OCT devices with enhanced depth imaging programmes can effectively evaluate the choroidal thickness.13 To understand the pathogenesis of pregnancy related ocular disorders, it is important to know the normal ocular adaptations that occur during pregnancy. Therefore, in this study we aimed to investigate the changes in the choroidal thickness during normal pregnancy using enhanced depth imaging spectral domain OCT and to compare these changes with healthy non-pregnant women. To the best of our knowledge, there have been no previous studies reported in the literature demonstrating choroidal thickness changes of the same women throughout their pregnancy.
METHODS Study population This observational, cross-sectional study involved 54 eyes of 27 otherwise healthy pregnant women
Dadaci Z, et al. Br J Ophthalmol 2015;0:1–5. doi:10.1136/bjophthalmol-2014-306343
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://bjo.bmj.com/ on April 29, 2015 - Published by group.bmj.com
Clinical science and 50 eyes of 25 age matched healthy non-pregnant women. All the pregnant women were recruited between November 2013 and February 2014 and evaluated at the Mevlana University Eye Clinic. The research protocol was approved by the Mevlana University Ethics Committee and followed the tenets of the Declaration of Helsinki. Written informed consent was obtained from each subject before enrolment in the study.
Study measurements Healthy pregnant women at gestational weeks 6–8 and healthy non-pregnant women in the follicular phase of the menstrual cycle were included in the study. Subjects with any ocular pathology including refractive disorders greater than ±1.0 dioptres, best corrected visual acuity 0.05). There were no twin gestations. The clinical data of the subjects are presented in table 1. Compared to the measurements obtained in the first trimester, the choroidal thickness measurements obtained in the third trimester were significantly decreased at all measured points, in both eyes of the pregnant women. At the fovea, the mean (±SD) choroidal thickness measured in the first trimester was 349.22±82.11 μm in the right eyes and 341.30±85.22 μm in the left eyes, which decreased to 333.56±76.61 μm in the right eyes ( p=0.014) and 326.93±75.84 μm in the left eyes (p=0.024) in the third trimester (table 2). Enhanced depth
Table 1 Clinical data (presented as mean±SD) of the pregnant women in the first and the third trimesters (n=27) and the control group (n=25) Control group
First trimester
Third trimester
p Value*
NA −0.17±0.51 −0.09±0.60 14.32±3.16 15.04±2.88
6.8±0.8 −0.20±0.45 −0.23±0.47 14.15±1.97 14.44±2.10
35.1±1.9 −0.24±0.48 −0.28±0.46 13.22±2.08 13.59±2.07
NA 0.271 0.244 0.030† 0.019†
Choroidal thickness measurements Choroidal thickness, defined as the distance between the outer portion of the hyperreflective line that corresponds to the retinal pigment epithelium and the inner surface of the sclera, was measured using the manual calliper function of the Cirrus HD-OCT software. Seven measurements perpendicular to the retina pigment epithelial layer were obtained for each scan: one at the fovea; three located at, respectively, 500, 1000, and 1500 μm nasal; and three located at, respectively, 500, 1000, 2
Gestational age (weeks) RE (dioptres, right eyes) RE (dioptres, left eyes) IOP (mm Hg, right eyes) IOP (mm Hg, left eyes)
*Comparison between the first and third trimesters. †Significant difference between the first and third trimesters. IOP, intraocular pressure; NA, not applicable; RE, refractive error.
Dadaci Z, et al. Br J Ophthalmol 2015;0:1–5. doi:10.1136/bjophthalmol-2014-306343
Downloaded from http://bjo.bmj.com/ on April 29, 2015 - Published by group.bmj.com
Clinical science Table 2 Choroidal thickness measurements (mean±SD in μm) of healthy pregnant women in the first and the third trimesters (n=27) and the control group (n=25) Right eyes
N3 N2 N1 SF T1 T2 T3
Left eyes
Control group
First trimester
Third trimester
p Value*
Control group
First trimester
Third trimester
p Value*
269.92±52.47 292.32±53.24 308.88±48.01 318.88±53.13 311.24±55.14 300.44±55.52 282.88±56.47
292.15±76.33 319.81±77.87 340.00±76.54 349.22±82.11 339.33±78.83 321.15±76.14 297.81±71.41
282.15±74.43 307.33±73.50 327.15±68.07 333.56±76.61 317.74±75.23 307.00±73.42 284.30±68.36
0.020 0.027 0.044 0.014
BJO Online First, published on February 20, 2015 as 10.1136/bjophthalmol-2014-306343 Clinical science
Changes in choroidal thickness during pregnancy detected by enhanced depth imaging optical coherence tomography Zeynep Dadaci,1 Husnu Alptekin,2 Nursen Oncel Acir,1 Mehmet Borazan1 1
Department of Ophthalmology, Mevlana University School of Medicine, Konya, Turkey 2 Department of Obstetrics and Gynecology, Mevlana University School of Medicine, Konya, Turkey Correspondence to Dr Zeynep Dadaci, Department of Ophthalmology, Mevlana University School of Medicine, Aksinne M., Esmetas S., No: 16, Meram, Konya 42040, Turkey; [email protected] Received 3 November 2014 Revised 28 December 2014 Accepted 5 February 2015
ABSTRACT Aim To compare the choroidal thickness measurements of healthy pregnant women obtained in the first trimester with measurements obtained in the third trimester using enhanced depth imaging optical coherence tomography (OCT). Methods 54 eyes of 27 healthy pregnant women and 50 eyes of 25 age matched healthy women were enrolled in this observational, cross-sectional study. The pregnant women underwent two OCT scans, one in the first trimester at gestational weeks 6–8, and the other during the third trimester at gestational weeks 32–37; the control group had OCT scanning during the follicular phase of the menstrual cycle, using the enhanced depth imaging mode. Choroidal thicknesses were measured at the fovea, at three locations nasal, and at three locations temporal to the fovea at 500 μm intervals. Results The choroidal thickness measurements obtained in the third trimester were significantly decreased in all measured points in both eyes compared to the measurements obtained in the first trimester ( p0.05). Conclusions Choroidal thickness was found to be significantly decreased in healthy pregnant women during the third trimester compared to the first trimester. This finding can provide valuable information when interpreting pregnancy related ocular disorders.
INTRODUCTION
To cite: Dadaci Z, Alptekin H, Oncel Acir N, et al. Br J Ophthalmol Published Online First: [please include Day Month Year] doi:10.1136/ bjophthalmol-2014-306343
Women’s physiology changes markedly during normal pregnancy. The most distinct alterations occur in the hormonal and cardiovascular systems. There is a dramatic increase in the concentrations of both oestradiol and progesterone.1 Oestradiol is known to induce nitric oxide synthases and increased concentrations of nitric oxide, which is a potent vasodilator, lead to a decrease vascular tone both in the luteal phase of the menstrual cycle and in pregnancy.2 Blood volume starts to increase in the first gestational weeks and reaches a peak in the third trimester. Consequently, peripheral vascular resistance decreases throughout the pregnancy, preventing a rise in the mean arterial blood pressure (MAP).1 The blood flow is redistributed and the
perfusion of certain organs, such as the uterus, breasts, and kidneys, increases.3 Besides the normal physiological adaptations, pregnancy is also a period of various pathologies, some of which are unique to pregnancy. From an ophthalmological point of view, various ocular conditions may occur uniquely during pregnancy and some ocular diseases, such as diabetic retinopathy, may worsen.4 Previous studies have reported increased central corneal thickness,5 changes in corneal curvature, and intraocular pressure (IOP)6 during pregnancy. Pre-eclampsia or eclampsia associated retinopathy and amniotic fluid embolism are unique to pregnancy.4 Also, it is known that pregnancy is a major risk factor for some ocular pathologies such as central serous chorioretinopathy (CSC).7 Choroid is the vascular structure of the eye supplying blood to vital ocular structures. It has some unique characteristics; in contrast to the retina, autoregulation of the blood flow is limited in the choroid and it has intense autonomic innervation.8 Also, increased sympathetic activity and decreased parasympathetic activity occurs in patients with CSC,9 which is one of the most common ocular pathologies encountered in pregnant women. The choroid can also change its thickness to compensate for various ocular conditions, as in response to retinal defocus,10 and its thickness is reported to change in various ocular pathologies, such as central retinal vein occlusion and CSC.11 12 The enhanced depth mode of optical coherence tomography (OCT) allows us to investigate the changes in the choroidal layer of the eye in vivo. Using this method, high resolution cross sectional images of the posterior segment of the eye can be obtained. In particular, OCT devices with enhanced depth imaging programmes can effectively evaluate the choroidal thickness.13 To understand the pathogenesis of pregnancy related ocular disorders, it is important to know the normal ocular adaptations that occur during pregnancy. Therefore, in this study we aimed to investigate the changes in the choroidal thickness during normal pregnancy using enhanced depth imaging spectral domain OCT and to compare these changes with healthy non-pregnant women. To the best of our knowledge, there have been no previous studies reported in the literature demonstrating choroidal thickness changes of the same women throughout their pregnancy.
METHODS Study population This observational, cross-sectional study involved 54 eyes of 27 otherwise healthy pregnant women
Dadaci Z, et al. Br J Ophthalmol 2015;0:1–5. doi:10.1136/bjophthalmol-2014-306343
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://bjo.bmj.com/ on April 29, 2015 - Published by group.bmj.com
Clinical science and 50 eyes of 25 age matched healthy non-pregnant women. All the pregnant women were recruited between November 2013 and February 2014 and evaluated at the Mevlana University Eye Clinic. The research protocol was approved by the Mevlana University Ethics Committee and followed the tenets of the Declaration of Helsinki. Written informed consent was obtained from each subject before enrolment in the study.
Study measurements Healthy pregnant women at gestational weeks 6–8 and healthy non-pregnant women in the follicular phase of the menstrual cycle were included in the study. Subjects with any ocular pathology including refractive disorders greater than ±1.0 dioptres, best corrected visual acuity 0.05). There were no twin gestations. The clinical data of the subjects are presented in table 1. Compared to the measurements obtained in the first trimester, the choroidal thickness measurements obtained in the third trimester were significantly decreased at all measured points, in both eyes of the pregnant women. At the fovea, the mean (±SD) choroidal thickness measured in the first trimester was 349.22±82.11 μm in the right eyes and 341.30±85.22 μm in the left eyes, which decreased to 333.56±76.61 μm in the right eyes ( p=0.014) and 326.93±75.84 μm in the left eyes (p=0.024) in the third trimester (table 2). Enhanced depth
Table 1 Clinical data (presented as mean±SD) of the pregnant women in the first and the third trimesters (n=27) and the control group (n=25) Control group
First trimester
Third trimester
p Value*
NA −0.17±0.51 −0.09±0.60 14.32±3.16 15.04±2.88
6.8±0.8 −0.20±0.45 −0.23±0.47 14.15±1.97 14.44±2.10
35.1±1.9 −0.24±0.48 −0.28±0.46 13.22±2.08 13.59±2.07
NA 0.271 0.244 0.030† 0.019†
Choroidal thickness measurements Choroidal thickness, defined as the distance between the outer portion of the hyperreflective line that corresponds to the retinal pigment epithelium and the inner surface of the sclera, was measured using the manual calliper function of the Cirrus HD-OCT software. Seven measurements perpendicular to the retina pigment epithelial layer were obtained for each scan: one at the fovea; three located at, respectively, 500, 1000, and 1500 μm nasal; and three located at, respectively, 500, 1000, 2
Gestational age (weeks) RE (dioptres, right eyes) RE (dioptres, left eyes) IOP (mm Hg, right eyes) IOP (mm Hg, left eyes)
*Comparison between the first and third trimesters. †Significant difference between the first and third trimesters. IOP, intraocular pressure; NA, not applicable; RE, refractive error.
Dadaci Z, et al. Br J Ophthalmol 2015;0:1–5. doi:10.1136/bjophthalmol-2014-306343
Downloaded from http://bjo.bmj.com/ on April 29, 2015 - Published by group.bmj.com
Clinical science Table 2 Choroidal thickness measurements (mean±SD in μm) of healthy pregnant women in the first and the third trimesters (n=27) and the control group (n=25) Right eyes
N3 N2 N1 SF T1 T2 T3
Left eyes
Control group
First trimester
Third trimester
p Value*
Control group
First trimester
Third trimester
p Value*
269.92±52.47 292.32±53.24 308.88±48.01 318.88±53.13 311.24±55.14 300.44±55.52 282.88±56.47
292.15±76.33 319.81±77.87 340.00±76.54 349.22±82.11 339.33±78.83 321.15±76.14 297.81±71.41
282.15±74.43 307.33±73.50 327.15±68.07 333.56±76.61 317.74±75.23 307.00±73.42 284.30±68.36
0.020 0.027 0.044 0.014
