As an example, Clark et al (Archives of Disease in Childhood, 1992; 67 1233):
Inclusion criteria for this screening programme was all infants of birth weight less than 1500g and/or less than 32 weeks gestation.
The first examination was at 7 weeks old, with 32 weeks gestation equivalent being the lower limit. After that, babies were examined every two weeks until term.
If there was no retinopathy of prematurity by the estimated date of delivery, the baby was discharged from the screening.
In cases of discovery of retinopathy of prematurity, babies were followed up until the condition either regressed or treatment was indicated. All of these infants were reviewed until they were three years old.
Infants actually treated were followed up more regularly and continue to be followed up.
Last reviewed 01/2018