No disease and gestational age at birth of ≤ 25 weeks
No disease and gestational age at birth age of >25 weeks
Mild disease (Stage 1 or Stage 2 in Zone II, without plus)
Mild stable disease (Stage 1 or Stage 2 in Zone II) and stable for four weeks
Type 2 ROP Pre-Threshold
Zone I any stage; Zone 2
Stage 2; Stage 3 in Zone II or III without plus, Pre-Plus may be present
every 2-7 days until no longer Type 2 pre-threshold.
Type 1 or Threshold ROP
Zone 1 any stage with plus disease
Stage 3 in Zone I, Stage 3 in Zone II or III with plus
treatment recommended within 72 hours with follow up weekly thereafter until regression.
Regressing ROP and vascularized into Zone III
The frequency of the follow-up depends upon the severity of the disease, zone of involvement, the presence or absence of plus disease, and the rate of progression noted from previous examinations.