Red Eye

Question 1

Visual Development

Answer 1

• Prenatal
Visual Development
• 6 Weeks gestation ocular structures defined
• Correspondence differrentiation of brain
• Teratogenic factors during first trimester may cause ocular defects
• EG. Severe optic nerve hypoplasia is a results of early insult at 6- 10 weeks gestation

• Birth (full term)
• Visual system relatively mature
• Ocular tissues differentiated
• Axial length 70% adult size (17mm)
• Anterior chamber more developed than • posterior
• CNS still maturing

Question 2

Post-natal Growth - visual development

Answer 2

• 4 months foveal differentiation complete
• 6 months nerve pathway myelination pathway • complete
• Anterior segment mature at 3 years
• Posterior segment grows until 16 years

Question 3

Paediatric ophthalmology - Types of defects

Answer 3

• Reduced Visual Acuity
• Strabismus (squint)
• Abnormal ocular movements
• Nystagmus
• Ocular torticollis
• Subjective symptoms – diplopia, asthenopia, • reduced vision etc

Question 4

Paediatric ophthalmology - causes of reduced vision

Answer 4

• Refractive error
• Amblyopia
• Defective visual acuity of one or both eyes, which persists
• after the correction of any refractive error and the removal of
• any pathological obstruction to vision eg cataract
• It is a cortical phenomenon caused by unequal competitive input from the 2 eyes into the visual cortex.

Question 5

Stages of visual development 1 month to 12 months

Answer 5

• 1 month
• pupils react to light
• defensive blink present by 6-8 weeks
• 3 weeks onwards watches familiar nearby face when being fed
• gaze caught and held by dangling bright toy gently moved in line of vision at 15- 25 cm
• 3 months • very alert
Visual Development
• fixes and follows toy at 15-25cm
• converges eyes if toy brought toward eyes
• 6 months
• any squint now is abnormal
• reaches out for objects
• searches for toy once it leaves visual regard
• 9 months
Visual Development
• very alert to people
• immediately grasps for toys
• watches activities of people or animals within 3-4 metres with sustained interest for several minutes
• 12 months
• interest in pictures
• points to objects of interest

Question 6

outline how to examine for Red reflex

Answer 6

 Sit in front of the child and parent at about arm’s
length. Set the ophthalmoscope
to around +2 (green or black)
 Focus on the parent’s eyes to show that the test is non-invasive and recognition
of the normal red reflex in that particular ethnic group.
 Then focus on the child’s face
and encourage the child to
look at the light. Focus on the red reflex within the pupil.

Question 7

Assessing visual acuity in children

Answer 7

• Qualitative
Assessing visual acuity
• Fixation preference
• Objection to occlusion
• Visually directed reaching (2-5 months)

Quantitative
Preferential looking
Cardiff Cards (fading optotype) Kay Pictures
Crowded / Uncrowded LogMAR LogMAR / Snellen

Question 8

Strabismus Manifest Deviation

Answer 8

• Esotropia Convergent

* Exotropia Divergent

Question 9

Strabismus Latent Deviation ( Phoria ) two types

Answer 9

• Esophoria ( Latent convergence)

* Exophoria ( Latent divergence )

Question 10

Strabismus Management

Answer 10

• Correct refractive error • Occlusion for amblyopia • Orthoptic Exercises
• Optical treatment
• Pharmacological
• Surgery

Question 11

Conjunctivitis presentation and management

Answer 11

• Close contacts affected
• Unilateral  bilateral
• Sticky discharge
• Diffuse redness
• Cornea and pupil normal
• Chloramphenicol
• Cellulitis- Refer urgently
• Neonatal conjunctivitis: refer urgently
– Risk of corneal perforation from n. gonorrhoea