Demographic data of the study subjects
The mean age of 12 pregnant women was (33.36±3.90)(27~37) years old. More than half of pregnant women (7/12) have refractive errors, which were associated with high education.
Ocular parameters in different trimesters of pregnancy
The value changes of parameters between groups are shown in Fig.1 and Fig.2.And the comparison of study parameters between groups was shown in Table 1: IOP, K1, K2, AL, ACD, CCT, CEC, TMH, BUT, MV, CST, CAT, and RNFL. The results were pairwise compared at 4-time points observed, respectively, for repeated measure ANOVA performed. The bolded font was used for the parameters with statistically significant differences. A statistically significant difference was found in IOP in the third trimesters compared with the first, and the second trimester and postpartum measurements (p<0.05). The IOP was found to be lowest in the third trimester (12.99±2.01mmHg). The MV of the second was significantly higher than that of the first trimester (p=0.023), but there was no significant difference between the third trimester and postpartum.
In the quantitative assessment during the first, second, and third trimesters of pregnancy and at 7 days postpartum, no statistically significant differences were found regarding mean K1, K2, AL, ACD, CCT, CEC, TMH, BUT, CST and CAT values. There was no statistically significant difference in the other parameters between measurement periods (p > 0.05 for all time points) (Table 1).
Table 1. Clinical data (presented as mean±SD) of the pregnant women pregnancy (n=12).
Variable
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
p
(1vs2)
|
p
(1vs3)
|
p
(1vs4)
|
p
(2vs3)
|
P
(2 vs 4)
|
p
(3 vs 4)
|
CEC
|
2593.55±249.24
|
2628.18±244.58
|
2615.35±238.12
|
2605.43±228.96
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
CCT (mm)
|
0.54±0.03
|
0.54±0.03
|
0.54±0.02
|
0.54±0.04
|
0.287
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
AL (mm)
|
24.15±1.34
|
24.16±1.35
|
24.17±1.34
|
24.12±1.31
|
1.000
|
1.000
|
0.677
|
0.969
|
0.703
|
0.228
|
K1(D)
|
43.30±1.38
|
43.34±1.37
|
43.37±1.46
|
43.29±1.41
|
1.000
|
0.796
|
1.000
|
1.000
|
1.000
|
0.653
|
K2(D)
|
44.29±1.27
|
44.27±1.29
|
44.33±1.30
|
44.36±1.34
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
ACD (mm)
|
3.38±0.30
|
3.40±0.30
|
3.42±0.31
|
3.38±0.30
|
0.789
|
0.255
|
1.000
|
1.000
|
1.000
|
0.459
|
CST (um)
|
236.38±19.77
|
237.04±22.54
|
238.67±21.44
|
236.50±20.20
|
1.000
|
1.000
|
0.149
|
0.492
|
1.000
|
0.697
|
MV (mm2)
|
9.77±0.22
|
9.858±0.254
|
9.871±0.230
|
9.804±0.291
|
0.023
|
0.091
|
1.000
|
1.000
|
0.428
|
0.885
|
CAT (um)
|
272.71±6.26
|
273.83±7.21
|
274.17±6.60
|
272.79±6.68
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
RNFL (um)
|
100.38±6.57
|
101.46±6.97
|
102.08±7.58
|
100.04±7.58
|
1.000
|
0.084
|
1.000
|
1.000
|
0.630
|
0.011
|
TMH (mm)
|
0.23 ±0.04
|
0.24 ±0.06
|
0.25±0.04
|
0.23±0.05
|
1.000
|
0.274
|
1.000
|
1.000
|
1.000
|
0.357
|
BUT(s)
|
9.16±7.34
|
9.81±4.13
|
8.73±4.70
|
8.64±5.48
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
1.000
|
IOP (mmHg)
|
14.30±1.90
|
13.83±2.19
|
12.99±2.01
|
13.59±1.89
|
0.909
|
0.002
|
0.052
|
0.006
|
1.000
|
0.050
|
One-way analysis of variance for repeated measures.
Bold values indicate significance at the p<0.05 level.
Abbreviations: CEC, corneal endothelium cell; CCT, central corneal thickness; AL, Axial length; K1, flat keratometry; K2, steep keratometry; ACD, anterior chamber depth; CST, central subfield thickness; MV, macular volume; CAT, cube average thickness; RNFL: Retina nerve fiber layer; TMH: tear meniscus height; BUT, Break-up time; IOP, intraocular pressure.
1 vs 2 means comparison between 1st Trimester and 2nd Trimester; 1 vs 3 means comparison between 1st Trimester and3rd Trimester; 1 vs 4 means comparison between 1st Trimester and Postpartum; applied for the latter.
Correlations between hormones
The specific concentration of estrogen and progesterone cannot be obtained in the third trimester, because the hormone level exceeds the threshold value of the instrument. Thus, we did not perform the correlations analysis of those data.
The partial correlations between biomechanical parameters and hormone levels were listed in Table 2 to Table 7. We analyzed the correlation between different hormones in different trimesters and different parameters. β-hCG peaked in the first trimester, but there only was a significant positive correlation between K2, ACD, and TMH in the second trimester (rk2 = 0.588, p = 0.045; rACD = -0.740, p = 0.006; rTMH = 0.642, p = 0.024). In studying the correlation between ophthalmic parameters and luteinizing hormone, we found a significantly negative correlation with MV (r=-0.598, p =0.040 in the first trimester; r = -0.672, p = 0.017); and CAT (r=-0.598, p =0.040 in the first trimester; r=-0.672, p =0.040 in the second trimester). Meanwhile, luteinizing hormone was correlated with ACD (r =-0.702, p=0.011) in the 2nd trimester and K2 (r =0.585, p=0.046) in the 3rd trimester. A negative correlation was found between the follicle stimulating hormone and CEC, MV and CAT in the first trimester (r= -0.677, p =0.016; r = -0.602, p =0.039; r = -0.584, p =0.046; respectively) and AL in the third trimester (r=-0.618, p =0.032). We interestingly found that the correlation between estradiol and ocular parameters only appeared with CST in the first trimester (r =-0.621, p =0.031) and RNFL (r=0.594, p=0.041) postpartum. In addition, our work showed the statistically correlation between progesterone and MV (r =0.583, p =0.047) and TMH (r= 0.762, p =0.004) in the first trimester. In postpartum, there were not any significant correlation in ocular parameters between prolactin ((all p > 0.05).
Table 2. Correlations between β-hCG and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
-0.493
|
0.103
|
-0.029
|
0.929
|
-0.089
|
0.783
|
CCT (mm)
|
-0.342
|
0.276
|
0.265
|
0.405
|
-0.300
|
0.344
|
AL (mm)
|
-0.039
|
0.905
|
-0.407
|
0.189
|
-0.445
|
0.147
|
K1 (D)
|
0.119
|
0.712
|
0.469
|
0.124
|
0.449
|
0.143
|
K2 (D)
|
0.062
|
0.847
|
.588*
|
0.045
|
0.397
|
0.201
|
ACD (mm)
|
-0.245
|
0.442
|
-.740**
|
0.006
|
-0.233
|
0.466
|
CST (um)
|
-0.155
|
0.631
|
-0.131
|
0.684
|
-0.229
|
0.475
|
MV (mm2)
|
-0.490
|
0.106
|
-0.089
|
0.784
|
-0.245
|
0.442
|
CAT (um)
|
-0.493
|
0.103
|
-0.081
|
0.803
|
-0.268
|
0.400
|
RNFL (um)
|
-0.311
|
0.325
|
-0.150
|
0.642
|
-0.152
|
0.638
|
TMH (mm)
|
-0.220
|
0.493
|
.642*
|
0.024
|
-0.113
|
0.727
|
BUT(s)
|
0.069
|
0.832
|
0.421
|
0.173
|
-0.017
|
0.958
|
IOP (mmHg)
|
0.361
|
0.249
|
0.154
|
0.633
|
-0.058
|
0.859
|
Bold values indicate significance at the p<0.05 level.
Table 3. Correlations between the luteinizing hormone and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
-0.615*
|
0.033
|
-0.040
|
0.901
|
0.324
|
0.304
|
-0.500
|
0.098
|
CCT (mm)
|
-0.016
|
0.961
|
0.394
|
0.205
|
-0.299
|
0.345
|
-0.124
|
0.701
|
AL (mm)
|
-0.180
|
0.575
|
-0.233
|
0.467
|
-0.300
|
0.344
|
0.100
|
0.757
|
K1 (D)
|
0.444
|
0.148
|
0.359
|
0.252
|
0.516
|
0.086
|
0.357
|
0.255
|
K2 (D)
|
0.295
|
0.352
|
0.366
|
0.242
|
0.585*
|
0.046
|
0.214
|
0.503
|
ACD (mm)
|
0.004
|
0.990
|
-0.702*
|
0.011
|
0.010
|
0.976
|
0.103
|
0.750
|
CST (um)
|
-0.116
|
0.720
|
-0.386
|
0.216
|
-0.011
|
0.974
|
-0.150
|
0.641
|
MV (mm2)
|
-0.598*
|
0.040
|
-0.672*
|
0.017
|
-0.035
|
0.913
|
-0.441
|
0.151
|
CAT (um)
|
-0.599*
|
0.040
|
-0.655*
|
0.021
|
-0.011
|
0.973
|
-0.467
|
0.126
|
RNFL (um)
|
-0.125
|
0.699
|
0.124
|
0.700
|
-0.063
|
0.847
|
-0.246
|
0.441
|
TMH (mm)
|
0.011
|
0.973
|
0.293
|
0.356
|
0.013
|
0.969
|
0.559
|
0.059
|
BUT(s)
|
0.076
|
0.813
|
-0.309
|
0.328
|
0.166
|
0.606
|
0.112
|
0.728
|
IOP (mmHg)
|
0.122
|
0.705
|
0.291
|
0.359
|
-0.453
|
0.139
|
-0.051
|
0.875
|
Bold values indicate significance at the p<0.05 level.
Table 4. Correlations between the follicle-stimulating hormone and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
-0.677*
|
0.016
|
-0.019
|
0.954
|
0.119
|
0.712
|
-0.500
|
0.998
|
CCT (mm)
|
0.086
|
0.790
|
0.334
|
0.288
|
0.002
|
0.995
|
-0.124
|
0.439
|
AL (mm)
|
-0.056
|
0.863
|
0.030
|
0.926
|
-.618*
|
0.032
|
0.100
|
0.097
|
K1 (D)
|
0.459
|
0.134
|
0.084
|
0.796
|
0.540
|
0.070
|
0.357
|
0.013
|
K2 (D)
|
0.334
|
0.289
|
0.041
|
0.898
|
0.564
|
0.056
|
0.214
|
0.021
|
ACD (mm)
|
0.212
|
0.508
|
-0.062
|
0.848
|
-0.456
|
0.136
|
0.103
|
0.955
|
CST (um)
|
0.104
|
0.748
|
0.141
|
0.663
|
-0.244
|
0.445
|
-0.150
|
0.561
|
MV (mm2)
|
-0.602*
|
0.039
|
-0.267
|
0.401
|
-0.131
|
0.686
|
-0.441
|
0.879
|
CAT (um)
|
-0.584*
|
0.046
|
-0.305
|
0.335
|
-0.075
|
0.817
|
-0.467
|
0.933
|
RNFL (um)
|
-0.154
|
0.633
|
-0.417
|
0.177
|
0.263
|
0.409
|
-0.246
|
0.962
|
TMH (mm)
|
-0.121
|
0.708
|
-0.236
|
0.460
|
-0.161
|
0.616
|
0.559
|
0.881
|
BUT(s)
|
-0.191
|
0.552
|
0.317
|
0.315
|
0.147
|
0.648
|
0.112
|
0.224
|
IOP (mmHg)
|
-0.163
|
0.614
|
-0.016
|
0.961
|
-0.082
|
0.800
|
-0.051
|
0.474
|
Bold values indicate significance at the p<0.05 level.
Table 5. Correlations between estradiol and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
0.468
|
0.125
|
0.045
|
0.889
|
-
|
-
|
0.369
|
0.238
|
CCT (mm)
|
0.260
|
0.415
|
-0.485
|
0.110
|
-
|
-
|
0.326
|
0.301
|
AL (mm)
|
-0.283
|
0.373
|
-0.100
|
0.758
|
-
|
-
|
-0.284
|
0.371
|
K1 (D)
|
-0.084
|
0.795
|
0.000
|
0.999
|
-
|
-
|
0.151
|
0.639
|
K2 (D)
|
-0.028
|
0.930
|
0.007
|
0.983
|
-
|
-
|
0.326
|
0.301
|
ACD (mm)
|
-0.533
|
0.074
|
0.194
|
0.546
|
-
|
-
|
-0.471
|
0.122
|
CST (um)
|
-0.621*
|
0.031
|
-0.087
|
0.789
|
-
|
-
|
-0.385
|
0.217
|
MV (mm2)
|
-0.032
|
0.922
|
0.321
|
0.309
|
-
|
-
|
-0.088
|
0.785
|
CAT (um)
|
-0.039
|
0.904
|
0.361
|
0.249
|
-
|
-
|
0.091
|
0.779
|
RNFL (um)
|
0.452
|
0.140
|
0.396
|
0.203
|
-
|
-
|
0.594*
|
0.041
|
TMH (mm)
|
0.318
|
0.314
|
0.144
|
0.656
|
-
|
-
|
-0.097
|
0.765
|
BUT(s)
|
0.243
|
0.447
|
-0.252
|
0.430
|
-
|
-
|
0.200
|
0.533
|
IOP (mmHg)
|
0.327
|
0.300
|
-0.103
|
0.750
|
-
|
-
|
-0.061
|
0.851
|
Bold values indicate significance at the p<0.05 level.
Table 6. Correlations between progesterone and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
0.318
|
0.315
|
-0.061
|
0.850
|
-
|
-
|
-0.370
|
0.237
|
CCT (mm)
|
-0.299
|
0.344
|
-0.269
|
0.397
|
-
|
-
|
-0.115
|
0.721
|
AL (mm)
|
0.055
|
0.865
|
-0.047
|
0.885
|
-
|
-
|
0.159
|
0.622
|
K1 (D)
|
-0.190
|
0.554
|
0.129
|
0.689
|
-
|
-
|
0.117
|
0.717
|
K2 (D)
|
-0.093
|
0.775
|
0.039
|
0.905
|
-
|
-
|
0.174
|
0.589
|
ACD (mm)
|
0.290
|
0.361
|
0.363
|
0.246
|
-
|
-
|
-0.050
|
0.877
|
CST (um)
|
0.205
|
0.524
|
-0.071
|
0.826
|
-
|
-
|
0.094
|
0.770
|
MV (mm2)
|
0.583*
|
0.047
|
0.310
|
0.326
|
-
|
-
|
0.075
|
0.817
|
CAT (um)
|
0.352
|
0.262
|
0.305
|
0.335
|
-
|
-
|
0.090
|
0.782
|
RNFL (um)
|
0.056
|
0.862
|
0.136
|
0.672
|
-
|
-
|
-0.422
|
0.171
|
TMH (mm)
|
0.762**
|
0.004
|
0.115
|
0.723
|
-
|
-
|
0.473
|
0.120
|
BUT(s)
|
0.347
|
0.270
|
0.471
|
0.122
|
-
|
-
|
0.427
|
0.166
|
IOP (mmHg)
|
-0.216
|
0.501
|
-0.053
|
0.870
|
-
|
-
|
-0.097
|
0.764
|
Bold values indicate significance at the p<0.05 level.
Table7. Correlations between human prolactin and biomechanical parameters during pregnancy.
Parameter
|
1stTrimester
|
2ndTrimester
|
3rdTrimester
|
Postpartum
|
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
|
CEC
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.198
|
0.536
|
CCT (mm)
|
-
|
-
|
-
|
-
|
-
|
-
|
0.549
|
0.064
|
AL (mm)
|
-
|
-
|
-
|
-
|
-
|
-
|
0.280
|
0.378
|
K1 (D)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.163
|
0.612
|
K2 (D)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.225
|
0.482
|
ACD (mm)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.095
|
0.769
|
CST (um)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.222
|
0.488
|
MV (mm2)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.396
|
0.202
|
CAT (um)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.342
|
0.276
|
RNFL (um)
|
-
|
-
|
-
|
-
|
-
|
-
|
0.212
|
0.508
|
TMH (mm)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.003
|
0.992
|
BUT(s)
|
-
|
-
|
-
|
-
|
-
|
-
|
-0.137
|
0.671
|
IOP (mmHg)
|
-
|
-
|
-
|
-
|
-
|
-
|
0.166
|
0.607
|
Bold values indicate significance at the p<0.05 level.