Visual acuity in children with retinopathy of prematurity (ROP) in four consecutive survey periods
| Period | 1975–1987 (survey 3) | 1986–1994 (survey 4) | 1994–2000 (survey 5) | 2000–2009 (survey 6) |
| Infants (n) | 76 | 87 | 51 | 42 |
| Visual acuity unspecified (%) | 5.1 | |||
| Not partially sighted or blind (VA >0.3) (%)* † | 2 | 10.3 | 9.8 | 23.8 |
| Partially sighted (VA 0.1–0.3) (%) | 34.3 | 31.0 | 25.5 | 38.1 |
| Socially blind (VA <0.1–≥1/60) (%) | 12.1 | 10.3 | 11.8 | 14.3 |
| Practically blind (VA <1/60–LP) (%) | 8.1 | 21.8 | 25.5 | 16.7 |
| Completely blind (VA =0) (%)‡ | 38.4 | 26.4 | 27.5 | 7.1 |
| Treatment of acute ROP§ | 24 | 43.9 | 56.9 | 66.7 |
↵* Infants with unilateral blindness and infants whose vision is expected to deteriorate in the future.
↵† Column 1 vs 4 p=0.000, 2 vs 4 p=0.043.
↵‡ Column 1 vs 4 p=0.000, 2 vs 4 p=0.010 and 3 vs 4 p=0.012.
↵§ Column 1 vs 2 p=0.013, 1 vs 3 p=0.000, 1 vs 4 p=0.000, 2 vs 4 p=0.014.
LP, light perception; VA, visual acuity.