Risk Factors Related to Progression to Threshold Retinopathy of Prematurity in Extremely Premature Infants

Lee, Kyoung Yeon; Jee, Youn Hee; Chang, Moo Hwan; Chang, Young Pyo

Abstract

PURPOSE: This study was intended to evaluate the risk factors related to the progression to threshold retinopathy of prematurity(ROP) after the first diagnosis of ROP in extremely premature infants.
METHODS
We retrospectively reviewed the medical records of 41 infants with gestational ages of less than 28 weeks and birth weight of less than 1,250 g who took ophtalmologic examination for ROP during admission to NICU from January 1997 to December 2001. The infants who were diagnosed as ROP were classified into two groups the group that progressed to threshold ROP ("threshold ROP group", n=15) and the self-regressed prethreshold ROP group("prethreshold ROP group", n=18). We compared the risk factors and the changes of daily transcutaneous oxygen saturation during the two weeks after the first diagnosis of ROP between these two groups.
RESULTS
Thirty three(80.5%) of 41 infants developed ROP. Fifteen(36.6%) progressed to threshold ROP after the diagnosis of ROP. The incidences of threshold ROP increased according to the lower birth weight in extremely premature infants. The progression to threshold ROP after the first diagnosis of ROP was significantly associated with the number of transfusions and birth weight(P<0.05, P<0.05, respectively). Daily mean arterial oxygen saturations of infants with threshold ROP during two weeks after the first diagnosis of ROP were higher than those of infants with prethreshold ROP(P<0.05).
CONCLUSION
The occurrences of threshold ROP were related to lower birth weight and more frequent transfusions and higher daily mean transcutaneous oxygen saturation during two weeks after the first diagnosis of ROP.