Distribution of cases of ⩾ stage 3 retinopathy of prematurity (ROP) by birth weight and city
| 500–749 g | 750–999 g | 1000–1250 g | |
| City 1 | 5 | 9 | 1 |
| City 2 | 2 | 1 | 1 |
| City 3 | 0 | 1 | 0 |
| City 4 | 1 | 0 | 0 |
| City 5 | 1 | 3 | 0 |
| Total ⩾ stage 3 ROP | 9 | 14 | 2 |
| Total babies screened | 48 | 149 | 224 |
| % of screened babies with severe ROP | 18.8 | 9.4 | 0.9 |
| 95% CI | 9.0 to 32.6 | 5.2 to 15.2 | 0.1 to 3.2 |