The National Eye Institute in 1999 sponsored a multicenter ... any stage ROP that was less than threshold Zone II, Stage 2 ROP with plus disease Zone II, Stage 3 ROP without plus disease Zone ...

This leads to phase 2 ROP. This process is demonstrated in Fig 2. Stage 1 A line of demarcation ... through the ridge toward the center of the eye (intravitreous) instead of following their ...

Most use the International Classification of Retinopathy of Prematurity system with five stages progressing from a temporal retinal demarcation line in stage 1 ... seen by other eye care ...