Gestational age-specific nomograms for fetal eyeball depth and intraocular measurements using 3-D ultrasound

To establish gestational age-specific nomograms for fetal eyeball anteroposterior (AP) diameter and intraocular measurements (lens AP diameter, vitreous body AP diameter).

A retrospective study was conducted and included singleton pregnancies without prenatal or postnatal structural abnormalities. Three-dimensional ultrasound volumes of the fetal face acquired between 12 and 41 weeks' gestation were analyzed using multiplanar reformatting to obtain a standardized axial orbital plane. Right and left eyeball, lens, and vitreous body AP diameters were measured. Gestational age-specific reference ranges were generated using percentile distributions. Quadratic regression was used to assess associations with gestational age and biparietal diameter.

Of 608 volumes screened, 588 were included. Complete assessment of all parameters was available in 577 (98.1%). All ocular and intraocular measurements increased with gestational age (all p < 0.001). Quadratic regression demonstrated associations between gestational age and eyeball AP diameter (right R² = 0.80; left R² = 0.79), lens AP diameter (right R² = 0.44; left R² = 0.42), and vitreous body AP diameter (right R² = 0.80; left R² = 0.81). Similar associations were observed with biparietal diameter (all p < 0.001). Gestational age-specific nomograms and percentile tables are presented.

Gestational age-specific nomograms for fetal eyeball depth and intraocular measurements are provided and may support objective prenatal assessment of fetal ocular growth.