Paediatric Ophthalmology

Question 1

What is leukocoria?

Answer 1

A white pupil, which is concerning especially in children as it means the red reflex has been lost. There is opacity in the optical media of the eye.

Question 2

What do you need to immediately exclude with leukocoria?

Answer 2

Retinoblastoma

Can dilate child’s pupils with cyclopentolate

Question 3

What is Retinopathy of Prematurity (ROP)?

Answer 3

• ROP is a proliferative neuropathy affecting premature infants of LBW, who have been exposed to high ambient O2 concentration.
• Retina doesn’t get blood vessels until 4th month of gestation: vessels grow towards nasal periphery after 8 months but they won’t reach temporal periphery until ~1 month after birth.
• This incompletely vascularised area is susceptible to O2 damage in premature infant.
• Avascular retina produces VEGF in utero which is the stimulus for vessel migration in the developing retina
• With premature birth and oxygen therapy, production of VEGF is downregulated by relative hyperoxia, therefore halting blood vessel development. Subsequently the increased metabolic demand of the growing eye allows excessive VEGF production which leads to neovascular complications of ROP.

Question 4

Who should be screened for ROP?

Answer 4

Babies born

Question 5

What is the treatment for ROP?

Answer 5

Laser photocoagulation, successful in 80%. If left untreated can progress to sight threatening complications such as vitreous haemorrhage and retinal detachment.

Question 6

What is retinoblastoma?

Answer 6

Most common primary intraocular malignancy of childhood. Comes from malignant transformation of primitive retinal cells before they finally differentiate. As these cells disappear within first few years of life, it is uncommon after 3yrs old.

Question 7

What are the causes of retinoblastoma?

Answer 7

• The gene predisposing retinoblastoma is 13q14, heritable is 40%
• Non-heritable is 60%. The tumour is unilateral, not transmissible and does not predispose to second nonocular cancers.
• If patient has a solitary RB and no positive FH, this is probably/not definitely non-heritable so risk in each sibling and offspring is 1%.
• In both Rb the risk of metastatic disease is greater if tumour is advanced and if there is optic nerve invasion. massive choroidal invasion, anterior chamber involvement and orbital spread.

Question 8

What is the treatment for retinoblastoma?

Answer 8

• Depends on site of tumour and visual prognosis

- Involves combination of chemotherapy, radiotherapy, brachytherapy and enucleation (removing eyeball)

Question 9

Describe congenital cataracts

Answer 9

• This is another cause of leukocoria, they occur in ~3/10,000 live births
• 2/3s are bilateral and the cause can be identified in about half of those affected. Most common cause is genetic mutation, usually autosomal dominant.
• Other causes include chromosomal abnormalities, metabolic disorders and intrauterine infections.
• Unilateral cataracts are usually sporadic, without a FH or systemic disease and affected infants are usually full-term and healthy
• Conditions associated with congenital cataracts: Down’s, cytomegalovirus, Rubella, Varicella, Edward Syndrome

Question 10

What is the treatment for bilateral dense cataracts?

Answer 10

Require early surgery when the child is 4-6 weeks to prevent development of ambylopia (lazy eye, failure to develop visual acuity).
Bilateral partial cataracts may not require surgery at all.

Question 11

What is the treatment for unilateral dense cataracts?

Answer 11

Urgent surgery (possibly within days) followed by aggressive anti-ambylopia therapy, despite which results are often poor.

Question 12

What are the causes of leukocoria?

Answer 12

• Coat’s disease
• Retinoblastoma
• Intraocular infection
• Congenital cataract