Changes in the nomenclature of ROP according to the International Classification of Retinopathies of Prematurity – a current review of the literature

Introduction: The International Classification of Retinopathy of Prematurity (ICROP) is a consensus that establishes a standard nomenclature for the classification of retinopathy of prematurity (ROP). Initially published in 1984, the classification was expanded in 1987 and again in 2005. In 2019, the revised ICROP was introduced. The third edition (ICROP3), first presented in June 2021, represents a further step in detailing the systematization of knowledge, based on new observations of lesions that emerged during the use of new therapies, such as intraocular anti-vascular endothelial growth factor (anti-VEGF), which result in regression and regeneration of retinal vascularization. These therapies have coincided with the advent of modern imaging methods in ophthalmology. The authors present changes in ROP nomenclature in response to the newly observed and described retinal-vascular lesions in active ROP and in states of ROP regression.Materials and methods: The new findings and principles of ICROP3, grounded in evidence-based medicine and expert consensus, address the development of new diagnostic and therapeutic methods and new clinical manifestations noted by numerous researchers in the literature.Results: The new ROP nomenclature retains many of the existing terms while refining and adding new elements to the classification, including posterior zone II, the introduction of the term “notch”, subcategories for stage 5, the abandonment of the term “aggressive posterior retinopathy of prematurity” (AP-ROP) in favor of “aggressive retinopathy of prematurity” (A-ROP), and updated descriptions of the course of reactivation and regression. Continued advancements in the science and understanding of ROP lesions will lead to future improvements and updates in this area of ophthalmology.Conclusions: This presentation of the new classification aims to enhance ophthalmologists’ knowledge of ROP classification. It can improve the quality and standardization of ROP treatment by expanding preventive testing and improving evaluations in the clinical care of premature infants.