Retinopathy of prematurity in extremely premature infants.

INTRODUCTION

The incidence and severity of retinopathy of prematurity (ROP) in extremely premature infants have not been reported since publication of the Early Treatment of ROP study results. The survival rate of these infants continues to increase. We sought to determine the characteristics of ROP in a group of surviving infants <25 weeks estimated gestational age (EGA) at birth compared to a group 25 to 27 weeks EGA at birth.

METHODS

Retrospective review of infants born prior to 27 weeks EGA between January 2003 and July 2007 at a level-3 nursery at a regional academic medical center.

RESULTS

A total of 231 medical records were reviewed and found to have analyzable data. Of 79 infants <25 weeks EGA, 69 (87%) developed ROP, compared to 95 of 152 (62%) infants 25 to 27 weeks EGA. Type 1 ROP developed in 23% of infants in the <25 weeks EGA group, compared to 9% of infants in the 25 to 27 weeks EGA group. There was no difference in mean postmenstrual age when type 1 ROP was diagnosed. Lower birth weight predicted increased risk of type 1 ROP in the 25 to 27 weeks EGA group, but not in the <25 weeks EGA group.

CONCLUSIONS

Extremely premature infants are more likely to develop ROP and type 1 ROP, but the incidence may be lower than previously reported. Birth weight may not influence the incidence of type 1 ROP in this group of infants. Type 1 ROP does not develop at an earlier postmenstrual age in the extremely premature infant.