ObjectiveTo measure and analyze the tortuosity of retinal veins in neonatal and premature infants quantitatively. MethodsA retrospective clinical study. The fundus images of the left eyes were selected from 30 healthy neonates and 30 premature infants without retinopathy of prematurity underwent RetCam screening. There were 16 premature infants with a history of oxygen inspiration. The tortuosity of superior temporal veins, inferior temporal veins, superior nasal veins, inferior nasal veins was measured separately using a self-developed computer program. Pearson correlation analysis was used to analyze the relationship between tortuosity of retinal veins and birth weight, gestational age and correct gestational age. ResultsIn full-term neonatal infants, the vascular tortuosity of the nasal veins was significantly higher than the temporal veins (t=5.73, P < 0.01), while the superior veins and inferior veins showed no significant difference (t=0.39, P > 0.05). There was no correlation between vascular tortuosity of temporal (r=0.179, -0.175) or nasal veins (r=0.055, 0.345) with birth weight or gestational age (P > 0.05). In premature infants, the vascular tortuosity of the nasal veins was also significantly higher than the temporal veins (t=5.00, P < 0.01), no significant difference was found between the superior veins and inferior veins (t=0.39, P > 0.05). The vascular tortuosity of temporal veins of premature infants was negatively correlated with birth weight (r=-0.375, P < 0.05); however, no significant correlation was found with gestational age (r=-0.296, P > 0.05). The vascular tortuosity of the temporal retinal veins of premature infants with a history of oxygen inspiration was significantly higher than premature infants without a history of oxygen inspiration (t=2.517, P < 0.05), though no significant difference was found between the nasal veins (t=-0.261, P > 0.05). The vascular tortuosity of the temporal and nasal retinal veins of premature infants was both higher than neonate, but was not statistically significant (t=0.88, 1.50; P > 0.05). ConclusionsThe vascular tortuosity of the temporal veins was greater than the nasal veins in both full-term and premature infants, though no significant difference was found between superior and inferior veins. The vascular tortuosity of temporal veins of premature infants increased as birth weight decreased. The vascular tortuosity of the temporal retinal veins of premature infants with a history of oxygen inspiration was higher than premature infants without a history of oxygen inspiration.