Longitudinal refractive development in 60 children with Down's syndrome
| Group | Definition | Number of patients | |
| Isometropia | |||
| Group 1 | Stable hypermetropia (spherical equivalent right eye <1.5 D difference between the first and last measurements) | 34 | |
| (1a) low grade hypermetropia (spherical equivalent right eye ⩽+2.0 at the last examination) | 18 | ||
| (1b) moderate hypermetropia (spherical equivalent right eye +2.25–+4.0 D at the last examination) | 12 | ||
| (1c) high grade hypermetropia (spherical equivalent right eye >+4.0 D at the last examination) | 4 | ||
| Group 2 | Increasing hypermetropia (spherical equivalent right eye ⩾1.5 D difference between the first and last measurements) | 11 | |
| Group 3 | Decreasing hypermetropia (spherical equivalent right eye ⩾1.5 D difference between the first and last measurements) | 9 | |
| or | |||
| development of myopia (spherical equivalent right eye <0 at the last examination) | |||
| Anisometropia | Difference between right and left eye at the last examination >1.0 D spherical and/or >1.5 D cylinder power | 6 | |
| Total | 60 | ||