Anatomic site of abnormality leading to visual impairment
| Anatomic site | No. of patients | Percentage of patients |
|---|---|---|
| Cortical | 212 | 30.5 |
| Hypoxic ischaemic encephalopathy/ancephalomacia | 61 | 8.8 |
| Cerebral palsy/periventricular leukomalacia | 41 | 5.9 |
| Epilepsy | 29 | 4.2 |
| Metabolic disorders | 26 | 3.7 |
| Agenesis of the corpus callosum | 15 | 2.2 |
| Down's syndrome | 13 | 1.9 |
| Developmental delay | 11 | 1.6 |
| Meningitis | 6 | 0.9 |
| Microcephaly | 4 | 0.6 |
| Trauma | 3 | 0.4 |
| Lissencephaly | 2 | 0.3 |
| Edwards syndrome (Trisomy 18) | 1 | 0.1 |
| Retina | 171 | 24.6 |
| Chorioretinal dystrophies | 64 | 9.2 |
| Retinopathy of prematurity | 48 | 6.9 |
| Oculocutaneous albinism | 27 | 3.9 |
| Bilateral spontaneous retinal detachment | 10 | 1.4 |
| Retinitis | 8 | 1.2 |
| Bilateral retinoblastoma | 6 | 0.9 |
| Leber congenital amaurosis | 5 | 0.7 |
| Coats’ disease | 2 | 0.3 |
| Bilateral choroidal haemangioma | 1 | 0.1 |
| Lens | 119 | 17.1 |
| Aphakia | 44 | 6.3 |
| Aphakic glaucoma | 24 | 3.5 |
| Cataract | 24 | 3.5 |
| Pseudophakia | 22 | 3.2 |
| Subluxated crystalline lens | 5 | 0.7 |
| Optic nerve | 67 | 9.6 |
| Primary optic atrophy | 26 | 3.7 |
| Secondary optic atrophy | 22 | 3.2 |
| Optic nerve hypoplasia | 12 | 1.7 |
| Isolated disc coloboma and morning glory disc | 7 | 1.0 |
| Refractive amblyopia | 40 | 5.8 |
| High myopia | 20 | 2.9 |
| Ametropic amblyopia | 14 | 2.0 |
| Meridional amblyopia | 6 | 0.9 |
| Congenital glaucoma/buphthalmos | 20 | 2.9 |
| Idiopathic nystagmus | 20 | 2.9 |
| Cornea | 18 | 2.6 |
| Sclerocornea | 5 | 0.7 |
| Corneal opacity | 5 | 0.7 |
| Keratoconus | 3 | 0.4 |
| Corneal dystrophy | 3 | 0.4 |
| Corneal scarring | 2 | 0.3 |
| Globe | 16 | 2.5 |
| Microphthalmos | 7 | 1.0 |
| Anophthalmos | 4 | 0.6 |
| Nanophthalmos | 3 | 0.4 |
| Cryptophthalmos | 1 | 0.1 |
| Phthisis bulbi | 1 | 0.1 |
| Uvea | 7 | 1.0 |
| Choroidal coloboma | 4 | 0.6 |
| Uveitis | 3 | 0.4 |
| Bilateral congenital ptosis (associated with refractive errors) | 5 | 0.7 |