Retinopathy of prematurity: the need for prevention

Figures & data

Figure 1 The ICROP committee published three parts on the classification of retinopathy of prematurity.

Note: The location and extent of the disease is specified using the images of the right and left eyes, zones I–III, and clock hours.
Abbreviation: ICROP, International Classification of Retinopathy of Prematurity.

Figure 2 Timecourse of ROP.

Notes: (A) Normal vessel growth starts at the beginning of the second trimester and is usually completed shortly before the full-term birth. This process is strongly associated with the adequate serum IGF-1 levels and postnatal growth. Hence, preterm birth will result in an incomplete vascularization of retina at birth. (B) The lack of growth factors, such as IGF-1, and the increased oxygen pressure (PaO₂) after birth result in a persistently avascular and thus hypoxic retina (Phase I), which will subsequently cause VEGF and other oxygen-sensitive vascular GFs to be produced in excess. (C) The result is retinal neovascularization (Phase II). In order to prevent vessel loss, infants at risk could be supplemented with IGF-1 starting at birth. This will make up for the lack of IGF-1 compared to the in-utero levels at a comparable gestational age to promote an adequate vessel growth. (D) If this preventative measure is not successful or if Phase II ROP has already occurred for other reasons, either laser coagulation or intravitreal anti-VEGF drugs could be used to treat these infants.
Abbreviations: IGF-1, insulin growth factor 1; PaO₂, partial pressure of oxygen; VEGF, vascular endothelial growth factor; GFs, growth factors; ROP, retinopathy of prematurity.