Table 1.
Frequency of refractive errors, strabismus and nystagmus in Down syndrome (DS) and control groups
| Defect | DS group n (%) | Control group n (%) | χ2 | P-value |
|---|---|---|---|---|
| Visual acuity (<6/18) | 8 (36.3) | 1 (1.3) | 9.99 | 0.00*,F |
| Myopia | 16 (38.1) | 1 (1.3) | 18.96 | 0.00*,C |
| Hyperopia | 4 (9.5) | 4 (5.2) | 0.29 | 0.457F |
| Astigmatism | 12 (28.6) | 5 (6.5) | 6.48 | 0.01*,C |
| Total refractive errors | 32 (76.2) | 11 (14.1) | 18.29 | 0.00*,C |
| Emmetropia | 10 (23.8) | 68 (87.2) | 10.89 | 0.00*,C |
| Strabismus | 4 (9.5) | 0 (0.0) | 5.01 | 0.01*,F |
| Nystagmus | 2 (4.8) | 0 (0.0) | 6.30 | 0.01*,F |
Notes:
*
Significant (P < 0.05);
F
P-value derived from Fisher’s exact test;
C
P-value derived from Pearson’s chi-square.