Objective:To investigate the perinatal risk factors and correlation between bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP).Methods:A retrospective analysis was performed on 173 preterm infants born at less than 32 weeks' gestation with BPD who were admitted to the neonatal intensive care unit (NICU) of the Women and Children's Hospital of Qingdao University from June 2017 to July 2022. According to the diagnostic criteria for ROP, these preterm infants were divided into the ROP group ( n=64) and the non-ROP group ( n=109). Chi-square test, two independent samples t-test, and Mann-Whitney U test were used to compare the general data, treatment, and the incidence of complications between the two groups. Multivariate logistic stepwise regression analysis was used to analyze the independent risk factors of ROP in preterm infants with BPD and the receiver operating characteristic (ROC) curve was drawn to analyze the predictive value of independent risk factors on ROP. The correlation between the severity of BPD and the incidence of ROP was analyzed. Results:The gestational age at birth [(28.0±1.1) vs. (28.8±1.2) weeks, t=4.01], the birth weight [(1 075.9±141.4) vs. (1 143.2±168.6) g, t=2.68], the partial pressure of carbon dioxide [42.5 mmHg (1 mmHg=0.133 kPa) (34.0-51.0 mmHg) vs. 47.0 mmHg (39.0-54.0 mmHg), Z=－2.31], and the total fluid intake on the first day of birth [80.0 ml (72.3-88.7 ml) vs. 83.6 ml (76.6-92.8 ml), Z=－2.28] in the ROP group were all lower than those in the non-ROP group (all P<0.05). While the prothrombin time [15.7 s (14.1-17.7 s) vs. 14.6 s (13.1-16.7 s), Z=－2.17], activated partial thromboplastin time [64.7 s (52.9-77.9 s) vs. 55.8 s (48.4-68.9 s), Z=－2.12], the proportion of patients treated with pulmonary surfactant [71.9% (46/64) vs. 49.5% (54/109), χ 2=8.25], the total duration of oxygen supplementation [50.5 d (40.0-64.0 d) vs. 45.0 d (37.0-52.0 d), Z=－2.77], the duration of invasive ventilation [5.0 d (1.0-11.0 d) vs. 1.0 d (0.0-5.0 d), Z=－4.03], the duration of noninvasive ventilation or high-flow oxygen therapy [(31.7±12.7) vs. (26.4±13.1) d, t=－2.59], and the incidence of neonatal respiratory distress syndrome [76.6% (49/64) vs. 57.8% (63/109), χ 2=6.22] were increased in the ROP group (all P<0.05). There was no significant difference in the proportion of BPD treated with corticosteroids between the ROP and non-ROP groups [60.3% (38/63) vs. 74.3% (81/109), χ 2=3.67, P=0.055]. Multivariate logistic stepwise regression analysis showed that smaller gestational age ( OR=1.599, 95% CI: 1.126-2.272, P=0.009), less fluid intake on the first day ( OR=1.033, 95% CI: 1.004-1.062, P=0.024), and longer duration of invasive ventilation ( OR=1.076, 95% CI:1.017-1.138, P=0.011) were independent risk factors for ROP in BPD infants, while glucocorticoid treatment was an independent protective factor ( OR=0.378, 95% CI:0.173-0.827, P=0.015). Most patients with mild or moderate BPD did not develop ROP [64.6% (73/113) and 66.7% (34/51)], while those with severe BPD were more likely to be complicated by ROP (7/9) ( χ 2=6.84, P=0.033). Conclusions:BPD infants with smaller gestational age, longer duration of invasive ventilation, and less fluid intake on the first day of birth are more likely to develop ROP, while glucocorticoid therapy can reduce the incidence of ROP in this population. Severe BPD may increase the risk of ROP in infants.