Incidence of severe retinopathy of prematurity (ROP) in five cities in England and in New South Wales (NSW), Australia
| Gestation |
Five cities in England | NSW Australia |
| <27 weeks | 20/95 (21.0) | 44/157 (28.0) |
| 27–28 weeks | 5/162 (2.6) | 15/269 (5.6) |
Data are expressed as number with severe ROP/number examined with the percentage in parentheses. The differences are not statistically significant.