Insights From The ETROP Study

How will this study change your practice?

Insights From The ETROP Study
How will this study change your practice?
By Michael T. Trese, MD

Researchers involved in the recent Early Treatment of Retinopathy of Prematurity (ETROP) Study reached some conclusions that will help us change our practices to achieve better outcomes.


Researchers in the ETROP study used a risk analysis program that considered the child's birth weight, postmenstrual age, race and zone of involvement, as well as factors like plus disease. The study's criteria called for treating patients who fell into these three categories:

  • Zone 1, any stage of ROP with plus disease
  • Zone 1, stage 3 with or without plus disease
  • Zone 2, stage 2 with plus disease.

The study's results give us some insight into how to treat ROP:

  • Screen carefully for zone and plus disease.
  • Identify flat vs. typical stage 3.
  • Be aware of the postmenstrual age, race and birth weight in risk analysis.
  • Treat patients within 48 hours.
  • Remember that if a child goes to standard Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Study threshold and progresses to retinal detachment, your treatment may be questioned.

The ETROP Study recommends a near confluent laser pattern.

The ETROP study has some drawbacks, particularly related to its definitions.

By ETROP criteria, you have the mandate to at least think about treating an eye that has one clock hour in Zone 1 and one clock hour of typical stage 3 in Zone 2, with or without plus disease. But this eye really behaves more like a Zone 2 eye, not a Zone 1 eye. Also, stage 3 eyes rarely are seen without plus disease, and flat stage 3 eyes can look like stage 1 or 2, especially to a novice examiner.


The most practical impact of ETROP on your practice involves scheduling. ROP changes very quickly, going from stage 1 to stage 5 in a couple of weeks. As the ETROP study shows, treatment should be done in 48 hours instead of 72 hours. In other words, if you diagnose a patient on Friday, treatment can't wait until Monday.

And based on this need for earlier treatment, we now need to be in the nursery twice a week. Weekly visits just aren't adequate for treating patients within our new time frame. By getting there more frequently and starting treatment within 48 hours, we'll be able to achieve better outcomes for our patients.

Dr. Trese is a clinical professor of biomedical sciences at the Eye Research Institute, Oakland University, Rochester, Mich., and a clinical associate professor at Kresge Eye Institute, Wayne State University, Detroit. He is chief of pediatric and adult vitreoretinal surgery at William Beaumont Hospital in Royal Oak, Mich.