Abstract
Purpose: :
Ocular circulation is influenced by the hormonal status. Ocular pulse amplitude is a surrogate measurement of choroidal blood flow. In this study we aimed to investigate the ocular pulse amplitude (OPA) profile during the different phases of pregnancy and to compare it with non-pregnant age-matched women.
Methods: :
In this cross-sectional study we enrolled 24 pregnant and 25 non-pregnant women (age-matched controls). Exclusion criteria were best corrected visual acuity < 20/20 and presence of any eye disease or systemic co-morbidity (including systemic hypertension and diabetes). Data collected included age, pregnancy period, Goldmann intraocular pressure (IOP) and central corneal thickness (CCT) using ultrasound pachymetry. OPA was measured using the Pascal Dynamic Contour Tonometer. The mean of three good quality measurements (quality index better than 3) was used for the analysis. Whenever both eyes were eligible, the right eye was arbitrarily selected.
Results: :
Mean age and CCT were similar between pregnant women (27.8±6 yrs, 547±25 µm) and controls (28.9±3.4 yrs, 546±28 µm; p>0.23). Pregnant women (mean gestation period, 20.4 ± 9 weeks) had a lower mean IOP than controls (11.4±2.4 vs 13±2.1 mmHg; p=0.02). Analysis of covariance (adjusting for IOP difference) revealed that OPA values in women in the 1st (3±0.6 mmHg) and 2nd trimester (2.5±0.7 mmHg) of pregnancy were increased compared to those in the last trimester (1.8±0.6 mmHg) and controls (2.1±0.7; p<0.05). Multivariate analysis showed that gestation period was the only variable associated to the changes in OPA values during pregnancy (r2=0.30, p<0.01). Age, CCT and IOP were not significant in this model.
Conclusions: :
Our results suggest that OPA values are increased in the first two trimesters of pregnancy, returning to normal values in the last 3 months. This changes in OPA values seem not be influenced by age, CCT or IOP.
Keywords: blood supply • intraocular pressure • clinical (human) or epidemiologic studies: natural history