Ocular manifestations of Noonan syndrome.

Noonan syndrome is a genetic condition inherited in an autosomally dominant manner, characterised by congenital heart disease, short stature, abnormal facies and the somatic features of Turner's syndrome, but a normal Karyotype. The ophthalmological and orthoptic findings on 58 patients with Noonan syndrome are reported. External features were hypertelorism (74%), downward sloping palpebral apertures (38%), epicanthic folds (39%) and ptosis (48%). The orthoptic examination revealed strabismus in 48%, refractive errors in 61%, amblyopia in 33%, and nystagmus in 9% of cases. Sixty-three per cent of cases had anterior segment changes consisting of: Prominent corneal nerves (46%), anterior stromal dystrophy (4%), cataracts (8%) and panuveitis (2%). Fundal changes occurred in 20% of the study group, including optic nerve head drusen, optic disc hypoplasia, colobomas and myelinated nerves. Forty-seven per cent required non surgical treatment and a further 16% had undergone surgery for strabismus or ptosis. Only three patients had no visual defects. With such a high incidence of ophthalmic abnormalities it is clearly important that children with Noonan syndrome are screened by an ophthalmologist at an early age.