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  • Update to the International ROP Classification System

    By Lynda Seminara
    Selected by Stephen D. McLeod, MD
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    Journal Highlights

    Ophthalmology, October 2021

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    Chiang et al., representing the Inter­national Committee for the Classifi­cation of Retinopathy of Prematurity (ICROP), recently revised the interna­tional consensus statement for classifying ROP. The goal of the revised guid­ance is to elevate the quality and standardization of ROP care throughout the world.

    The original consensus statement was published in 1984 and revised in 2005. Revisiting the guidance again was warranted to address multiple develop­ments in the field, including new ophthalmic imaging and pharmacologic thera­pies, concerns surrounding the subjectivity of ROP clas­sification, and recognition that ROP patterns in some parts of the world do not fit neatly into the existing classification system.

    An international committee of ROP experts was assembled in 2019; the committee represents 17 countries and includes 20 retina and 14 pediatric ophthalmologists.

    For the third edition of the classifi­cation system, ICROP3, the committee retained definitions such as zone (dis­ease location), stage (disease appear­ance at avascular-vascular junction), and circumferential extent of disease. Major changes include refined classi­fication metrics (including posterior zone II, notch, and subcategorization of stage 5) and recognition of the con­tinuum of vascular abnormality that exists from normal to plus disease. Also included is a definition of aggressive ROP (to replace aggressive-posterior ROP) because of the growing awareness that aggressive disease can occur in large preterm infants and can extend beyond the posterior retina, particular­ly in parts of the world that have limited resources. ROP regression and reactivation are described in detail in ICROP3, and more infor­mation on long-term sequelae is provided.

    ICROP3 marks a point in the journey to improve ROP care and outcomes, said the authors. They hope the updated material will improve the understanding of acute-phase ROP, including its regression and reactivation. They noted that more research is needed in areas such as quantification of vascular changes, characterization of clinical findings by other imaging modalities, and long-term risks of peripheral avascular retina. (Also see related commen­tary by Michael X. Repka, MD, in the same issue.)

    The original article can be found here.