Maternal ophthalmic artery Doppler velocimetry in pre-eclampsia in Southwestern Nigeria

Figures & data

Figure 1 Pie chart representation of study recruitment shows approximately equal proportions of pre-eclamptic patients and normotensive subjects.

Table 1 Characteristics of normal patients at the time of OAD scan

Characteristics	Frequency (n=41)	Percentage
Age (years)
<30	8	19.5
30–34	22	53.7
35–39	8	19.5
≥40	3	7.3
GA (weeks)
30	4	9.8
31	6	14.6
32	10	24.4
33	9	22.0
34	2	29.2
Parity
0	14	34.1
1	17	41.5
2	7	17.1
≥3	3	7.3
Systolic BP (mmHg)
<100	2	4.9
100–109	4	9.8
110–119	18	43.9
≥120	17	41.6
Diastolic BP (mmHg)
<60	0	0
60–69	11	26.8
70–79	21	51.2
≥80	9	22.0
Mean arterial pressure (mmHg)
<70	0	0
70–79	11	26.8
80–89	19	46.4
≥90	11	26.8

Abbreviations: BP, blood pressure; GA, gestational age; OAD, ophthalmic artery Doppler.

Table 2 Characteristics of pre-eclamptic patients

Characteristics	Frequency (n=42)	Percentage
Age (years)
<30	15	35.7
30–34	14	33.3
35–39	10	23.8
≥40	3	7.2
GA (weeks)
<30	8	19.0
30–34	23	54.8
35–39	11	26.2
≥40	0	0
Parity
0	18	42.8
1	11	26.2
2	5	11.9
≥3	8	9.1
Systolic BP (mmHg)
140–159	7	16.6
160–179	23	54.7
180–199	9	21.5
≥200	3	7.2
Diastolic BP (mmHg)
90–109	25	59.5
110–119	7	16.6
120–139	8	19.1
≥140	2	4.8
Mean arterial pressure (mmHg)
110–119	7	16.7
120–139	28	66.6
140–159	5	11.9
≥160	2	4.8

Abbreviations: BP, blood pressure; GA, gestational age.

Figure 2 Bar chart representation of the mean values of clinicodemographic characteristics of the normotensive and pre-eclamptic participants in the study. Note the similarity in the maternal and gestational ages of the pre-eclamptic patients and the normotensive patients.

Abbreviations: BP, blood pressure; PE, pre-eclampsia.

Table 3 Comparison of mean values of OAD parameters between the pre-eclamptic group and follow-up control group

Variable	Pre-eclamptic (n=41)	Control (2nd US) (n=41)	t-test	P-value
Right RI
(Mean ± SD)	0.62±0.10	0.70±0.10	−3.53	0.00*
Left RI
(Mean ± SD)	0.63±0.83	0.70±0.08	−4.20	0.00*
Right PI
(Mean ± SD)	1.2±0.50	1.60±0.40	−3.12	0.00*
Left PI
(Mean ± SD)	1.15±0.34	1.54±0.48	−4.24	0.00*
Right PSV (cm/sec)
(Mean ± SD)	28.16±9.15	32.10±12.30	−1.63	0.11
Left PSV (cm/sec)
(Mean ± SD)	29.77±10.69	33.88±12.22	−1.63	0.11
Right PDV (cm/sec)
(Mean ± SD)	22.56±7.13	19.06±6.82	2.28	0.03*
Left PDV (cm/sec)
(Mean ± SD)	25.43±8.73	19.85±7.34	3.15	0.00*
Right EDV (cm/sec)
(Mean ± SD)	9.85±3.31	8.76±4.00	1.35	0.18

Note:

* <0.05 is significant.

Abbreviations: SD, standard deviation; RI, resistivity index; PI, pulsatility index; PSV, peak systolic velocity; PDV, peak diastolic velocity; EDV, end diastolic velocity; OAD, ophthalmic artery Doppler; US, ultrasound.

Figure 3 Box plots for right RI, PI, PR, and EDV in control subjects at GA of 23±2 weeks (n=50), control subjects at GA of 32±2 weeks (n=41) and pre-eclamptic patients (n=42). (A) Box plots for right RI showing a positively skewed distribution in pre-eclamptics. Note that pre-eclamptic patients have lower RI values. (B) Box plots for the right PI showing a normal distribution in all the groups. Note that pre-eclamptic patients have lower PI values. (C) Box plots for the right PR showing a positively skewed distribution in control subjects. Note that pre-eclamptic patients have higher PR values. (D) Box plots for right EDV. A positively skewed distribution is shown in the control subjects.

Abbreviations: GA, gestational age; PR, peak ratio; RI, resistivity index; EDV, end diastolic velocity; PI, pulsatility index; Rt, right.

Figure 4 Box plots of MAP, RI, and PI among the pre-eclamptic subjects (mild pre-eclampsia [n=24], severe pre-eclampsia [n=18]). (A) Box plots for mean arterial pressure in those with mild pre-eclampsia and in those with severe pre-eclampsia. (B) Box plots for right RI among those with mild pre-eclampsia and those with severe pre-eclampsia. (C) Box plots for right PI among those with mild pre-eclampsia and those with severe pre-eclampsia.

Abbreviations: PE, pre-eclampsia; RI, resistivity index; PI, pulsatility index; MAP, mean arterial pressure.

Table 4 Comparison of BP and OAD metrics between patients with mild and severe pre-eclampsia

Variable	Mild PE (n=24)	Severe PE (n=18)	t-test	P-value
SBP (mmHg)
Mean ± SD	159.58±7.51	182.78±23.21	4.60	0.00*
DBP (mmHg)
Mean ± SD	99.17±4.08	118.89±14.10	6.52	0.00*
MAP (mmHg)
Mean ± SD	119.31±3.68	140.19±16.03	6.19	0.00*
Right RI
Mean ± SD	0.66±0.87	0.59±0.74	−2.44	0.02*
Right PI
Mean ± SD	1.24±0.38	1.02±0.23	−2.16	0.04*
Right PSV (cm/sec)
Mean ± SD	28.44±8.68	27.80±9.99	−0.22	0.83
Right PDV (cm/sec)
Mean ± SD	22.62±6.48	22.95±8.09	0.31	0.76
Right EDV (cm/sec)
Mean ± SD	9.51±2.93	10.31±3.79	0.77	0.44
Right PR	0.81±0.18	0.84±0.12	0.68	0.50

Note:

* P<0.05 is significant.

Abbreviations: BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; SD, standard deviation; RI, resistivity index; PI, pulsatility index; PSV, peak systolic velocity; PDV, peak diastolic velocity; EDV, end diastolic velocity; OAD, ophthalmic artery Doppler; PR, peak ratio; PE, pre-eclampsia.

Figure 5 ROC curves for OAD parameters to predict pre-eclampsia and its severity. (A) ROC curve for PDV to predict pre-eclampsia (AUC 0.69; 95% CI 0.59–0.79). (B) ROC curve for EDV to predict pre-eclampsia (AUC 0.657; 95% CI 0.55–0.76). (C) ROC curve for PR to predict pre-eclampsia (AUC 0.900; 95% CI 0.84–0.96). (D) ROC curve for RI to predict mild pre-eclampsia (AUC 0.709; 95% CI 0.54–0.88).

Abbreviations: AUC, area under the curve; CI, confidence interval; ROC, receiver operating characteristic; PR, peak ratio; RI, resistivity index; PDV, peak diastolic velocity; EDV, end diastolic velocity; OAD, ophthalmic artery Doppler.