Retinoblastoma

Definition: 
A malignant tumour of the retinal receptor cells

Incidence       
- 1 out of 23000 live births
- sporadic or dominantly inherited
- If bilateral, inherited or due to germ mutation may be transmitted
- Unilateral
– probably sporadic

Presentation  
– Strabismus
- White pupil

Examination   
- The entire retina of each eye must be examined by indirect ophthalmoscopy following dilation of the pupil.
- X-ray demonstrates the presence of calcium
- Examination of siblings is important
- Chromosome abnormality is occasionally seen

Treatment      
- Enucleation of one eye and irradiation of the second eye, if involved, unless diagnosis is certain from family history then bilateral irradiation.

Prognosis
- 80% survival if prompt early treatment
- 20% survival if tumour has spread to optic nerve or orbit.

 Leucocoria



Definition
– white pupil

Retrolental lesions may if large enough, reflect light out of the eye causing a white pupillary reflection.  Cataracts can be distinguished from a retrolental lesion.   

Differential Diagnosis
- Retinoblastoma
- Retrolental Fibroplasia
- Persistent Hyperplastic Primary Vitreous
- Congenital Toxoplasmosis
- Toxocariasis
- Coats Disease
- Chorioretinal Colobomas

Orbital Neoplasms


Infrequent in childhood. 
They include:- Rhabdomyosarcoma

Definition
- A Malignant tumour arising in the first ten years of life.  Usually unilateral.  It causes unilateral proptosis.  Its rapidity of growth may simulate infection
Diagnosis – CT Scan and biopsy

Management
– Radiation and Cytotoxic drugs

Prognosis
- > 80% 5 years survival

Leukaemic Infiltrations – usually bilateral   

Metastatic Neuroblastomas – lid ecchymoses with or without proptosis

Inflammatory Pseudotumour – presents with proptosis

Diagnosis
-Biopsy
-CT Scan

Therapy
– Corticosteroids – give a dramatic response

Histiocytosis X And Infantile Xanthogranulomas

Diagnosis
– Bony defects on X-ray
- Biopsy

Optic Nerve Glioma
– a benign tumour resulting in decreased vision proptosis and enlargement of the optic foramina.  If confirmed to the optic nerve prognosis is good.  If the chiasm is involved the prognosis is much worse.   

Craniopharyngioma

This cystic tumour causes chiasmal compression causing in visual field defects and optic atrophy.

Treatment
- surgery and radiotherapy
- monitor visual fields and optic nerve function