METHODS: A retrospective analysis was conducted on clinical data from infants diagnosed with ROP. The clinical outcomes were systematically evaluated, including the rates and process of spontaneous regression across different ROP stages and zones. Potential factors for spontaneous regression were also examined.

RESULTS: A total of 138 infants(138 eyes, for patients with bilateral involvement, the more severely affected eye was chosen)with ROP were included, consisting of 77 males and 61 females. The mean gestational age was 30.0±2.3 wk. Spontaneous regression was observed in 113 cases. The regression rates for stages 1, 2, and 3 were 100%, 81%, and 23%, respectively. Regression was observed in 100% of zone Ⅲ cases and 74% of zone II cases, but did not occur in zone I or in cases with plus disease. Higher gestational age and birth weight were associated with increased rates of spontaneous regression. The median postmenstrual age(PMA)at the onset of ROP regression was 39.8 wk and at the completion of regression was 48.4 wk, with a median regression duration of 8 wk. Zone II and higher-stage ROP(stages≥2)were associated with a later onset and completion of regression, as well as a longer regression duration. Further analysis revealed that mechanical ventilation duration>14 d and retinal hemorrhage were identified as risk factors impeding the spontaneous regression of ROP.

CONCLUSION: The spontaneous regression rate of ROP varies with stage, zone, gestational age, and birth weight. The regression rate is high for stage 1 and zone Ⅲ ROP, whereas it is lower for stage 2, zone II, and more severe forms of ROP, which require close monitoring or active intervention. The time course of spontaneous regression of ROP also differs by disease stage and zone.Mechanical ventilation lasting>14 d and retinal hemorrhage are risk factors impeding the spontaneous regression of ROP.