Retinopathy of prematurity classification updates: possible implications for treatment

Abstract

It seems indisputable that the treatment for a condition should be based on the current description and classification of the condition. But here, we ask: is this always so for treatment of severe retinopathy of prematurity (ROP)? The current indications for ROP treatment were defined in 2003 by the Early Treatment for ROP (ETROP) trial, as type 1 ROP, which includes stages 1 or 2 with plus disease in zone I, stage 3 with or without plus in zone I, and stages 2 or 3 with plus in zone II. 1 Early Treatment for Retinopathy of Prematurity Cooperative GroupRevised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial. Arch Ophthalmol. 2003; 121: 1684-1694 Crossref PubMed Scopus (1499) Google Scholar ETROP also defined type 2 ROP that is somewhat less severe but requires increased surveillance. Since then, the International Classification of ROP (ICROP) has been updated twice (in 2005 2 International Committee for the Classification of Retinopathy of PrematurityThe International Classification of Retinopathy of Prematurity revisited. Arch Ophthalmol. 2005; 123: 991-999 Crossref PubMed Scopus (2099) Google Scholar and 2021 3 Chiang MF, Quinn GE, Fielder AR, et al. International Classification of Retinopathy of Prematurity, Third Edition. Ophthalmology 2021;128:e51-e68. Google Scholar ), and critically new treatment modalities, such as antivascular endothelial growth factor agents, have been developed. 4 Mintz-Hittner H.A. Kennedy K.A. Chuang A.Z. BEAT-ROP Cooperative GroupEfficacy of intravitreal bevacizumab for stage 3+ retinopathy of prematurity. N Engl J Med. 2011; 364: 603-615 Crossref PubMed Scopus (987) Google Scholar , 5 Stahl A. Lepore D. Fielder A. et al. Ranibizumab versus laser therapy for the treatment of very low birthweight infants with retinopathy of prematurity (RAINBOW): an open-label randomised controlled trial. Lancet. 2019; 394: 1551-1559 Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar , 6 Wallace D.K. Kraker R.T. Freedman S.F. et al. Short-term outcomes after very low-dose intravitreous bevacizumab for retinopathy of prematurity. JAMA Ophthalmol. 2020; 138: 698-701 Crossref PubMed Scopus (29) Google Scholar Yet clinical practice and research are still based on earlier iterations of the ICROP, 2 International Committee for the Classification of Retinopathy of PrematurityThe International Classification of Retinopathy of Prematurity revisited. Arch Ophthalmol. 2005; 123: 991-999 Crossref PubMed Scopus (2099) Google Scholar ,7 Committee for the Classification of Retinopathy of PrematurityAn international classification of retinopathy of prematurity. Arch Ophthalmol. 1984; 102: 1130-1134 Crossref PubMed Scopus (1125) Google Scholar and there is evidence that some clinicians are treating severe disease more aggressively than recommended by ETROP. 8 Gupta M.P. Chan R.V.P. Anzures R. et al. Practice patterns in retinopathy of prematurity treatment for disease milder than recommended by guidelines. Am J Ophthalmol. 2016; 163: 1-10 Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar , 9 Adams G.G.W. Bunce C. Xing W. et al. Treatment trends for retinopathy of prematurity in the UK: active surveillance study of infants at risk. BMJ Open. 2017; 7e013366 Crossref Scopus (42) Google Scholar , 10 Liu T. Tomlinson L.A. Ying G.S. Yang M.B. Binenbaum G. G-ROP Study GroupTreatment of non-type 1 retinopathy of prematurity in the Postnatal Growth and Retinopathy of Prematurity (G-ROP) study. J AAPOS. 2019; 23: 332.e1-332.e6 Abstract Full Text Full Text PDF Scopus (7) Google Scholar , 11 Rajan R.P. Kohli P. Babu N. Dakshayini C. Tandon M. Ramasamy K. Treatment of retinopathy of prematurity (ROP) outside International Classification of ROP (ICROP) guidelines. Graefes Arch Clin Exp Ophthalmol. 2020; 258: 1205-1210 Crossref PubMed Scopus (6) Google Scholar Our purpose here is to open a discussion on how the ROP classification updates might affect the indications for ROP treatment, and whether potential changes require collaborative research and/or expert consensus opinion.