Characterization of the Progression Pattern in Retinopathy of Prematurity Subtypes.

PURPOSE

To evaluate differences in the progression pattern among subtypes of retinopathy of prematurity (ROP).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Premature infants screened for ROP.

METHODS

Medical records of 578 premature infants who were screened at the neonatal intensive care unit from September 2009 through March 2016 were reviewed. We matched for the number of patients, gestational age at birth, and postmenstrual age at the first examination between infants with spontaneously regressed ROP and those with treated ROP. A total of 133 premature infants who were born before 27 weeks' gestation were included.

MAIN OUTCOME MEASURES

The mean age at onset of any ROP and the duration from the initial examination to onset were compared between infants with regressed ROP and those with treated ROP. The mean age at treatment and the duration from onset to treatment were compared between infants with type 1 ROP and those with aggressive posterior ROP (AP-ROP). Data were analyzed for 1 randomly selected eye for each infant.

RESULTS

Of 133 premature infants with any ROP, 67 regressed spontaneously, 43 demonstrated type 1 ROP, and 23 demonstrated AP-ROP. Individual trajectories of ROP progression over time showed that AP-ROP progressed through the stages in a steep linear manner in most cases. In contrast, the type 1 ROP and regressed ROP developed in a slower, stepwise manner.

CONCLUSIONS

In infants with ROP, the disease trajectories across ROP stages are different based on the ROP subtype, despite postmenstrual age at onset being comparable across subtypes. Our findings could be useful for managing follow-up screening.