Indications for Early Treatment of Retinopathy of Prematurity

Abstract

Source: Early Treatment for Retinopathy of Prematurity Cooperative Group. Revised indications for the treatment of retinopathy of prematurity. Arch Ophthalmol.2003;121:1684–1694.Retinal detachment and reduced visual acuity from retinopathy of prematurity (ROP) continue to be major disabilities afflicting preterm infants.1 Investigators from 26 clinical sites collaborated to determine whether earlier treatment of infants at high risk for severe ROP resulted in improved visual acuity and retinal structural outcomes as compared with conventional treatment. Infants with birth weights less than 1,251g born from 2000 to 2002 were screened for ROP at 26 participating centers. If an infant developed ROP, parents were asked to consent to data collection and increased examination frequency. The threshold for treatment of ROP was defined as a risk of approximately 50% for retinal detachment. Infants with ROP were eligible for this randomized trial if the risk of progression to an unfavorable outcome in the absence of treatment was calculated to be 15% or higher and a second examination by a masked, study-certified ophthalmologist confirmed findings consistent with this risk. Of 828 infants whose parents had given consent for systematic follow-up of ROP, 499 were classified as high-risk for progression to an unfavorable outcome and 401 were ultimately enrolled. If both eyes were eligible for randomization, 1 eye was randomly assigned to earlier treatment with ablative therapy within 48 hours of the first diagnosis of high-risk ROR Treatment generally consisted of laser therapy, but cryotherapy was also allowed. The other eye served as the control and was managed conventionally (observed until it either reached threshold for treatment and was treated or the ROP regressed without progressing to threshold). In cases where only 1 eye reached high-risk prethreshold ROP, that eye was randomized either to treatment within 48 hours or to conventional management.The functional outcome of each randomized eye at a corrected age of 9 months was evaluated using Teller Acuity Cards to assess monocular acuity. Structural outcome was documented with a dilated fundus examination at corrected ages of 6 and 9 months by study-certified examiners. Based on the acuity outcomes at 9 months, there was a significant benefit from early treatment of eyes with high-risk ROP: 14.5% with unfavorable visual acuity outcome compared to 19.5% with conventional treatment. At 9 months, unfavorable structural outcomes were lower among patients in the early treatment group than among those receiving conventional treatment (9.1% versus 15.6%, P<.001). The authors conclude that early treatment of high-risk, prethreshold ROP significantly reduced unfavorable outcomes to a clinically important degree. Long-term follow-up is being conducted to learn whether the benefits noted in the first year after birth will persist into childhood.Despite major advances in the management of severe ROP, retinal detachment and reduced visual acuity from ROP continue to be one of the most common causes of severe visual impairment in childhood. During the past several years, the timing and indications for treatment of ROP have been questioned, with some physicians advocating earlier treatment and others recommending a more conventional wait-and-see approach. The primary concern about earlier treatment is the expected increase in surgical intervention in eyes with ROP that would otherwise regress without any treatment. This concern has led to efforts to identify treatment selection criteria that will result in earlier treatment only in those eyes at highest risk for an unfavorable visual or structural outcome in the absence of treatment.This study documents a significant improvement of structural and functional outcome in early treatment of eyes showing findings of aggressive proliferative ROP These criteria will lead to an increased number of surgeries in the high-risk group, since some of them may have had spontaneous resolution of their ROP if not treated. However, the outcome, on average, of each surgical procedure will likely be much improved. Whether a surgery in a particular case might not have been necessary can never be determined by the data presented here since this, like most studies, deals with statistical probability, not individual cases. My impression is that the results will be significantly better, both structurally and functionally, and I have adopted the authors’ recommendations in my own clinical ROP practice.