Kermorvant-Duchemin E, Meur GL, Plaisant F, et al. - Researchers here investigated the correlation between hyperglycemia and severe ROP in premature infants. Two independent cohorts of 863 (primary cohort) and 316 (validation cohort) preterm infants born at < 30 weeks’ gestation were employed to determine the correlation between severe retinopathy of prematurity and 2 markers of glucose exposure between birth and day 21. A third cohort—a prospective, nationwide population-based cohort of 1,441 preterm infants born at <30 weeks’ gestation, representing a large variation of practices regarding neonatal management— was used to determine the influence of strategies to avert or lower hyperglycemia on the risk of severe retinopathy of prematurity. Multiple sensitivity analyses and external validation reinforced the findings supporting the hypothesis that for severe retinopathy of prematurity, hyperglycemia is an independent risk factor and not a mere marker of illness. They recognized threshold levels of combined duration and blood glucose concentration that are noted to be significantly linked with an elevated risk of severe ROP: > 6 days with at least 1 glycemia value > 8 mmol/l, or > 3 days with at least 1 glycemia value > 10 mmol/l, or > 2 days with at least 1 glycemia value > 11 mmol/l. A10-fold raised risk of severe ROP was observed in correlation with being exposed to any of these situations. Per these data, overall average exposure and duration of hyperglycemia are more important than a single high glucose value. In this nationwide population-based cohort, a large but not significant effect was identified in the analysis of insulin as a protective factor against severe retinopathy of prematurity after controlling for confounding factors.