Risk analysis and an alternative protocol for reduction of screening for retinopathy of prematurity.

Purpose: To determine whether a multivariate risk model can select infants with low-risk eyes for an alternative protocol that reduces retinopathy of prematurity (ROP) screening without loss of effectiveness.

Methods: This was a retrospective, nonrandomized, comparative study. We assigned 712 eyes of 357 premature infants of 401-1,250 g birth weights as high or low risk for prethreshold or threshold ROP using a risk model with variables of birth weight, gestational age, multiple birth, race, and gender. Using simulations, infants with high-risk eyes (p > or = 0.15) were screened conventionally, while those with low-risk eyes were screened with the 35q3 protocol (initial examination at 35 weeks postmenstrual age followed by screening every 3 weeks, with increased or decreased intervals based on ROP severity). The resultant reduction in ROP screening and the delay to detection of severe ROP were calculated.

Results: The 35q3 protocol reduced the mean number of eye examinations per infant in the overall population by 13.4% (p = 0.0051). No eyes had a delay to the detection of threshold or type 1 zone 1 ROP. Of a total of 57 type 1 ROP eyes, 2 eyes with type 1 zone 2 ROP were delayed to detection by 1 week. As our study was done prior to the Early Treatment of ROP study, the 2 eyes were observed and regressed without progression to threshold ROP.

Conclusions: A risk-based alternative screening protocol increased the efficiency of ROP screening for infants of 401-1,250 g birth weight without an apparent loss of effectiveness. This investigational approach requires further validation by multicenter studies.