IGF1 and retinopathy of prematurity: This study aims to compare the performance of four algorithms, namely CHOP-ROP (Children's Hospital of Philadelphia ROP) [18, 19], WINROP (weight, insulin-like growth factor I, neonatal ROP) [10, 20], CO-ROP (Colorado retinopathy of prematurity model) [21], and G-ROP (postnatal growth and retinopathy of prematurity) [9] in an Australian tertiary level NICU setting.