Ophthalmology - Paeds

Question 1

Define strabismus

Answer 1

Misalignment of eyes - ‘squint’

Question 2

Define ambylopia

Answer 2

The affected eye becomes passive and has reduced function compared to the other dominant eye (‘lazy eye’)

Question 3

Define esotropia

Answer 3

Inward positioned squint (affected eye towards the nose)

Question 4

Define exotropia

Answer 4

outward positioned squint (affected eye towards the ear)

Question 5

Define hypertropia

Answer 5

upward moving affected eye

Question 6

Define hypotropia

Answer 6

downward moving affected eye

Question 7

What is the most common type of squint?

Answer 7

Esotropia (a convergent squint) - the misaligned eye diverges inwards towards the midline

Question 8

What is the most common cause of strabismus?

Answer 8

Usually idiopathic – no specific underlying cause

Question 9

Other causes of strabismus?

Answer 9

• Hydrocephalus
• Cerebral palsy
• Space occupying lesions e.g. retinoblastoma
• Trauma

Question 10

What is the key symptom of strabismus?

Answer 10

Diplopia

Question 11

What age does treatment for strabismus need to be started before? Why?

Answer 11

Before 8 years old - as up until 8 the visual field are still developing

Question 12

What are 2 management options for strabismus?

Answer 12

• Occlusive patch over good eye (force weaker eye to develop)
• Atropine drops in the good eye (force weaker eye to develop)

Question 13

What is the mechanism behind treating strabismus?

Answer 13

Forcing the weaker eye to develop

Question 14

How do atropine drops work in strabismus?

Answer 14

The purpose of atropine drops is to cause temporary blurred vision in the unaffected eye, thus muting the visual input from the eye to the brain, forcing the deviated eye to focus and therefore align.

Question 15

What class of drug are atropine drops?

Answer 15

Antimuscarinics

Question 16

What is ambylopia?

Answer 16

A visual impairment resulting from abnormal visual stimulation during childhood. Also known as a ‘lazy eye’.

Question 17

What is the most common cause of visual impairment in children?

Answer 17

Ambylopia

Question 18

How does ambylopia develop?

Answer 18

Occurs 2ary to reduced visual stimulation usually in one eye during the critical years of development, interfering with cortical visual development:

• Squints/strabismus
• Unequal refractive error
• Congenital cataracts

Question 19

Congenital vs paediatric cataracts?

Answer 19

Congenital - lens opacity which is present at birth

Paediatric - Diagnosed in older babies or children

Question 20

What are causes of congenital/paediatric cataracts?

Answer 20

• Genetics (FH)
• Conditions e.g. Down’s syndrome
• Infections picked up from mother during pregnancy – chickenpox, cytomegalovirus, herpes, rubella
• Diabetes
• Trauma post-birth
• Drug reactions

Question 21

Give some complications of congenital/paediatric cataracts

Answer 21

• Lazy eye
• Blindness

Question 22

What is the red reflex?

Answer 22

This refers to the reddish-orange reflection of light from the back of the eye which is observed when using an ophthalmoscope

Question 23

how is the red reflex affected in cataracts?

Answer 23

Absent red reflex can result from cataracts

Question 24

What is retinitis pigmentosa?

Answer 24

A congenital inherited condition where there is degeneration of the rods (responsible for vision at low light levels) and cones (colour vision) in the retina.

Question 25

Do rods or cones tend to degenerate more in retinitis pigmentosa?

Answer 25

Rods

Question 26

What tends to be the first presenting symptom in retinitis pigmentosa?

Answer 26

Night blindness tends to be first symptom (i.e. reduced visual acuity in dim light) due to degeneration of rods

Question 27

Function of rods vs cones?

Answer 27

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate colour vision, and have a low spatial acuity.

Cones are active at higher light levels (photopic vision), are capable of colour vision and are responsible for high spatial acuity.

Question 28

Describe vision loss in retinitis pigmentosa

Answer 28

Peripheral vision loss then central vision loss – ‘tunnel vision’

Question 29

Fundoscopy results in retinitis pigmentosa?

Answer 29

• Pigmentation – peripheral ‘bone-spicule’ pigmentation
• Optic disc pallor
• Retinal vessel attenuation (narrowing of arterioles) – mainly thought to reflect decreased metabolic demand of the degenerating retina

Question 30

What is the most common intraocular tumour of childhood?

Answer 30

Retinoblastoma

Question 31

What is a retinoblastoma?

Answer 31

Malignant tumour of the retina

Question 32

What is the defining feature of a retinoblastoma?

Answer 32

leukocoria (white pupil)

Question 33

Presentation of retinoblastoma?

Answer 33

• Leukocoria (white pupil)
• Deteriorating vision
• Strabismus
• Failure to thrive
• In developing countries, the tumour often presents as eye enlargement

Question 34

What is keratoconus?

Answer 34

Occurs when the cornea thins and gradually bulges outwards, resulting in loss of vision.

Question 35

Risk factors for keratoconus?

Answer 35

• FH
• Rubbing eyes vigorously
• Certain conditions e.g. retinitis pigmentosa, Down’s syndrome, Ehlers-Danlos syndrome, hayfever, asthma

Question 36

Presentation of keratoconus?

Answer 36

• Blurred or distorted vision
• Increased sensitivity to bright light
• Need for frequent changes in eyeglass prescriptions
• Sudden worsening or clouding of vision