Clinical and sociodemographic characteristics of children
| Child characteristics | N (%) total 99 |
|---|---|
| Age group* | |
| 10–12 years | 61 (62%) |
| 13–15 years | 38 (38%) |
| Gender | |
| Boys | 57 (58%) |
| Girls | 42 (42%) |
| Ethnicity | |
| Majority ethnicity (white ethnic groups) | 81 (81.8%) |
| Minority ethnicity (Asian, black, mixed, other non-white) | 18 (18.2%) |
| Index of multiple deprivation† | |
| 1: most deprived | 20 (21.1%) |
| 2 | 11 (11.6%) |
| 3 | 19 (20%) |
| 4 | 20 (21.1%) |
| 5: least deprived | 25 (26.3%) |
| Vision level‡ | |
| VI group A | |
| VI 1: LogMAR 0.50–0.70 | 43 (43.4%) |
| VI 2: LogMAR 0.72–1.00 | 35 (35.4%) |
| VI group B | |
| SVI: LogMAR 1.02–1.30 | 10 (10.1%) |
| Blind: LogMAR 1.32 or worse | 11 (11.1%) |
| Course of visual loss | |
| Stable§ | 55 (55.6%) |
| Progressive | 44 (44.4%) |
| Timing of VI onset | |
| Early (≤2 years) | 71 (71.7%) |
| Late | 28 (28.3%) |
| Diagnosis by site of VI¶ | |
| Whole globe and anterior segment | 2 (2%) |
| Glaucoma—primary or secondary | 8 (8.2%) |
| Cornea (sclerocornea and corneal opacities) | 4 (4.1%) |
| Lens (cataract and aphakia) | 10 (10.2%) |
| Uvea | 6 (6.1%) |
| Retina | 64 (65.3%) |
| Optic nerve | 10 (10.2%) |
| Cerebral/visual pathways | 5 (5.1%) |
| Other (idiopathic nystagmus, high refractive error) | 11 (11.2%) |
*Mean age=12.2, SD=1.9. †Based on UK postal code supplied by clinical team (missing in four children).
‡WHO categories of visual impairment based on acuity in better seeing eye. §Acceleration of visual loss was determined by the review of the notes and visual impairment characteristics by the leading author's (consultant ophthalmologist). ¶Does not add up to 100% because some children had visual impairment originating in multiple sites (missing in 1 child as diagnosis could not be obtained from the hospital where the patient was identified).
LogMAR, the logarithm of minimum angle of resolution; SVI, severe visual impairment; VI, visual impairment.