Retinoblastoma is a rare tumour of the eye affecting about 1 in 25 000 individuals. The majority are seen in children younger than 5 years. 10% are hereditary - dominant; the rest are sporadic. Bilateral tumours are most often familial; unilateral are always sporadic.

Presentation in infancy is with a white pupil - cat's eye - or a concomitant squint. In older children it may present as a posterior uveitis. Metastasis occurs later.

Unilateral tumours are treated by enucleation or laser ablation; bilateral by enucleation or laser ablation in the worst affected eye and external radiation to the other. Small tumours may be treated by radiation or cryotherapy.

Unilateral tumours have a 80% survival rate. Bilateral and advanced cases have a survival rate that falls to below 40%.