A preterm baby of 26 weeks of gestation is born. At what age should screening for Retinopathy of Prematurity (ROP) be done

Normally, for all Preterm babies ROP screening is done 32 weeks of gestation or 4 weeks postnatal life whichever is later. But, in newborn born < 28 weeks of gestation, ROP Screening is done at 3 weeks postnatal life.