Despite major advances in the treatment of retinopathy of prematurity (ROP), this disease remains a significant cause of blindness in the developed world. ROP as we know it probably did not exist before the advance in prenatal care that occurred in the mid-1950s, with enhanced survival that allowed children to live at an age where retinal vascularisation was incomplete and ROP could develop.

Additional recent advances in neonatology have influenced the incidence and severity of ROP in a dichotomous fashion. While many children who would have fought for survival two decades ago now remain quite healthy throughout their neonatal stay, others for whom death was nearly certain now fight for survival with reasonable odds. Thus, older children are healthier and probably at a decreased risk of ROP, whereas smaller children who would have died now live and are at high risk. How the interplay of these changes has influenced the incidence and severity of ROP is controversial.

In this issue of the BJO (1122), Larsson et al examine this question. The previous studies they cite were generally small, retrospective, and poorly controlled. Larsson et al, however, were …