Axial growth of the fetal eye and evaluation of the hyaloid artery: in utero ultrasonographic study

The aims of this prospective, cross-sectional study were to report axial oc ular growth during human gestation, to determine the presence of the hyaloi d artery (HA) and its blood flow, and to provide a timetable for HA regress ion. The study group comprised 231 low-risk singleton pregnancies between 1 4 and 38 weeks' gestation. Ocular axial length (OAL), anterior chamber dept h (ACD) and posterior chamber depth (PCD) were measured using high-resoluti on ultrasound. The growth of these eye segments in correlation with gestati onal age (GA) was established. The presence of the HA and its regression we re determined. By using power Doppler, ultrasound blood flow within the HA was estimated. HA regression is a gradual process that is not evident befor e 18 weeks' gestation. In all fetuses beyond 29 weeks' gestation, no HA cou ld be detected (P < 0.001). Blood flow within the HA was documented only un til the 16th week of gestation. The correlation coefficients, r = 0.924, 0. 784 and 0.929, for GAL, ACD and PCD, respectively, were found to be highly statistically significant (P < 0.0001). The present data offer normative me asurements of the fetal axial eye lengths, timetable for HA regression and flow cessation. Copyright (C) 2000 John Wiley & Sons, Ltd.