Prenatal ultrasonic measurements of the eye and the interorbital distance

Abstract

OBJECTIVES: The two-fold objective of this study was to ascertain whether the antero-posterior diameter of the fetal eye is comparable to the transversal diameter and to establish nomograms based on the measurements obtained for ocular diameter (OD), mean interorbital distance (MIOD) and the MIOD/biparietal diameter (BPD) ratio related to gestational age. TYPE: A prospective monocentric study based on 398 sonographic fetal eye measurements. RESULTS: The antero-posterior and transverse ocular diameters of the fetal eye remain comparable throughout pregnancy (R = 0.997, p < 0.0001). They were related to gestational age and BPD. The MIOD/BDP ratio decreased with gestational age. The OD/BPD ratio remained nearly constant. Nomograms were established for OD, MIOD and the MIOD/BPD ratio related to gestational age. DISCUSSION AND CONCLUSION: The fetal eye can be measured on any diameter provided the sonographic scan for the measurement is flawless. Nomograms and values are given. Hyper- and hypotelorism and microphthalmia can be found in numerous malformative syndromes. Previously published tables are not well-suited to the French population.