Abstract:

Objective

To investigate prenatal ultrasonographic methods for evaluating fetal eyelids and palpebral fissures and their imaging characteristics.

Methods

Ultrasonographic images of fetal eyelids and palpebral fissures in fetuses at various gestational weeks were prospectively collected from January 2023 to March 2024 at Shenzhen Longhua Maternal and Child Health Hospital. The imaging planes （coronal plane of the eyelids and mid-eyelid sagittal plane） and sonographic characteristic were systematically analyzed. Chi-square tests were used to compare left-right eyelid fissure echoic patterns in sagittal and coronal planes within the same gestational week， and the Fisher’s exact test was used to compare differences across gestational weeks. Postnatal ocular outcomes were tracked.

Results

A total of 125 normal fetuses at 15-40 gestational weeks were included， with 250 eyes （125 left， 125 right） evaluated via coronal and mid-eyelid sagittal planes. Eyelid and palpebral fissure echogenicity was rarely detectable before 15 weeks. With advancing gestation， eyelid echogenicity transitioned from flake-like moderate to hyperechoic.Visualization rates for palpebral fissures were 98.4% （left） and 96.0% （right） in coronal planes， and 96.8%（left） and 94.4% （right） in sagittal planes. Palpebral fissures manifested as linear hyperechoic， hypoechoic，or band-like anechoic structures. Before 20 weeks， fused eyelids displayed linear hyperechoic fissures. From 20-28 weeks， gradual eyelid separation yielded three patterns： linear hyperechoic， hypoechoic， or band-like anechoic. After 28 weeks， hypoechoic and anechoic patterns increased in prevalence. No significant left-right differences were observed in echoic patterns within the same gestational week （P＞0.05）. Across gestational weeks， significant differences were noted in linear hyperechoic and hypoechoic patterns （P＜0.05）， while band-like anechoic patterns showed no statistical variation （P＞0.05）. Postnatal follow-up confirmed normal eyelid and fissure development in all 125 cases.

Conclusion

Prenatal ultrasound enables effective evaluation of fetal eyelid and palpebral fissure development， enhancing prenatal detection of abnormalities.

Key words: Ultrasonography, Prenatal, Fetus, Eyelid, Palpebral fissure