Developmental diseases

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Cerebral visual impairment

Retrogeniculate visual impairment: pathology posterior to the LGN
CVI may be isolated
Causes
- Periventricular leukomalacia (common in premature infants)
- Intracranial haemorrhage
- Perinatal hypoxia
- Intrauterine infection
- Structural abnormalities
- Seizures
- Hydrocephalus
- Trauma
- Meningitis
- Encephalitis
Clinical features
- Normal ocular structures
- Normal pupillary responses
- Variable visual attentiveness
- Absent nystagmus
- Optic nerve cupping, especially in periventricular leukomalacia
Tests
- Neuroimaging: reveals PVL, cerebral atrophy, or other findings depending on cause
- VEP may be normal or subnormal

Axenfeld-reiger syndrome:
- Axenfeld anomaly: posterior embryotoxon and iris strands
- Reiger anomaly: strands and atrophy of the iris, corectopia, polycoria
- Reiger syndrome: anomaly, plus dental/facial bone abnormalities, umbilical abnormalities, pituitary involvement
- Iris hypoplasia
- Iridogoniodysgensis
Alagille syndrome: posterior embryotoxon with jaundice and cardiac defects. Autosomal dominant mutation in JAG1 gene on chromosome 20

See Optic Neuropathies section

OPA1 gene
Mild-moderate visual loss (>6/36)
Temporal pallor (triangle excavation) with loss of superficial capillaries at the temporal disc
Blue-yellow dyschromatopsia

Associated with
- PAX-6
- CMV
- Rubella
- Trisomy 13
- Intellectual disability
- Dwarfism
- Persistent hyperplastic primary vitreous
Describes a small,disorganisedglobe (cp with nanophthalmos wherein the eye is small but normally organised)
Management: the eye is the driver for growth of the eyelids and orbit
- Eyelid and fornix expansion: using series of enlarging conformers
- Orbital expansion: keep the eye in situ initially. Inflatable saline chambers, fillers, hydrogel pellets and then dermis fat graft

High hyperopia with short axial length
Crowded anterior segments: shallow anterior chambers
Thick/rigid, inelastic sclera: higher risk of choroidal detachments and haemorrhages
- During glaucoma or cataract surgery, prophylactic draining sclerotomies may be used to minimise choroidal effusion formation