One of the most severe morbidities affecting preterm infants is sight threatening ROP, a disorder characterized by reduced retinal vascularization followed by pathologic neovascularization which can lead to retinal detachment and blindness similar to diabetic retinopathy. ROP develops during the neonatal period and outcome is available around term age (40 postmenstrual weeks), which makes it a useful marker for short term outcome of neurovascular development in interventional studies.