Prethreshold ROP

Threshold Disease signifies stage of retinopathy of prematurity with ROP  in Zone II stage 3 (less than 5 contiguous or 8 non contiguous clock hours) or Zone II stage 3 (5 contiguous or 8 non contiguous clock hours) without plus disease or Zone I, stage 3  with / without plus disease. Many doctors use this as the current criteria of initiating treatment.