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Flashcards in Paeds Ophthalmology Deck (35):
1

What is strabismus?

A horizontal or vertical misalignment of visual axes

2

What is esotropia?

Horizontal misalignment of visual axes with convergence (in-turning) of the affected eye

3

What is exotropia?

Horizontal misalignment of visual axes with divergence (out-turning) of the affected eye

4

Hypertropia and hypotropia

hyper= upward and hypo = downward misalignment of the eye

5

Prevalence of strabismus

Esotropia prevalence approx 2% in childhood
Exotropia prevalence is less than 1%, (1/3 as prevalent as esotropia)

6

Causes of Esotropia

Infantile esotropia - assoc latent nystagmus, presents first 6m of life, large angle deviation
Accommodative esotropia: result of hypermetropia - exaggerated convergence, presents 1-2y, correcting refractive error will correct strabismus
Acquired non-accommodative esotropia: present 3-5y, no refractive errors, 10% assoc with neuro abnormalities
Neuro: CN 6 palsies most common (congenital or acquired)

7

Causes of exotropia

Infantile exotropia: first 6m
Exophoria/intermittent exotropia: eye tends to drift but normally maintains normal alignment, compensation sometimes fails

8

Clinical examination of a strabismus

Corneal light reflections: in a normal eye will be central and symmetrical
Cover test: covering the apparently normal eye - other eye will shift to take up fixation if it was misaligned
?nystagmus etc.
?Refractive error

9

Masquerades of strabismus (psedostrabismus)

Prominent epicanthal folds in infants (obscures nasal sclera so appears to be misaligned)
Telecanthus (larger distance between medial canthi than normal)
Hypertelorism (larger distance between eyes themselves than normal - bony path usually)
Angle Kappa (difference between pupillary and visual axis e.g. retinopathy of prematurity - peripheral retinal scarring - temporal displacement of maculae - fixation point of macula does not coincide with axis of pupil - appears exotropic) - cover test will be normal

10

Complications of untreated strabismus

?may miss an underlying ophthal or neuro problem
Ambylopia in 50-60% - significant vision loss

11

Management of strabismus

Glasses (in hypermetropic accommodative esotropia)
Eye exercises
Surgical correction - recession or resection of extraocular muscles as indicated
Aim for early realignment ASAP to prevent complications

12

Dye used for assessing corneal abrasions/ulcers

Fluroscein

13

Possible presentations of retinoblastoma

Strabismus
Poor vision
Known family history or retinoblastoma
Leukocoria (screening or parents may bring in odd photos)

14

Imaging in retinoblastoma

Ultrasound or MRI to show intralesional calcification typical of retinoblastoma

15

Sporadic v hereditary retinoblastoma

Sporadic: 2 separate mutations of Rb gene within a single retinoblast cell - ALWAYS UNILATERAL
Hereditary: 1st mutation occurs in germ cell (usually sperm), 2nd occurs within retinoblast - this more likely to be bilateral (not always though)

16

Poor prognostic factors of retinoblastoma

delay in diagnosis
larger tumour
older age
optic nerve involvement
extraocular extension
(5 year survival is 98%)

17

Management options for retinoblastoma

Photocoagulation
Cryotherapy
Radioactive plaques
External beam radiotherapy
Chemotherapy
Surgery (e.g. Enucleation - removal of eye)

Suggest family screening, especially if bilateral

18

Ophthalmia neonatorum causes

Bacterial:
Chlamydia (40%, D5-14)
N Gonorrhoea (D2-5) - severely swollen eyelid
Chemical inflammation (6-8h post chemical, resolves within 48)
Viral - HSV (

19

Complications of ophthalmia neonatorum

Corneal ulceration - perforation - BLINDNESS
pneumonia (chlamydia)
Sepsis

20

Epidemiology of nasolacrimal duct obstruction

6% prevalence in newborns
Most common cause of persistent tearing/ocular discharge in infants/kids
Spontaneous resolution by 6m in 90%
Unlikely to spontaneously resolve after 12m

21

Presentation of nasolacrimal duct obstruction

Chronic or intermittent tearing + debris on eyelashes
Conjunctiva/eyes are not inflamed or erythematous
May be mild erythema of lower lid
Dye disappearance test (if asymptomatic at time of assessment) - dye will not be drained after 5 minutes

22

Management of nasolacrimal duct obstruction

Lacrimal sac massage (downward pressure, 2-3sec, 2-3 times per day)
Lacrimal duct probing under GA if not resolved by 12m

23

Orbital cellulitis v periorbital cellulitis (anatomy and presentation)

Orbital is post-septal, periorbital is pre-septal
ORBITAL: systemically unwell, proptosis, redness of eye itself, impaired vision, ophthalmoplegia/pain on eye movements, pupil abnormality
PERIORBITAL: just erythema and swelling around eye - none of the above

24

Presentation of orbital cellulitis

acutely red and swollen eye
Proptosis, ophthalmoplegia, pain on eye movement, vision impairment, pupil abnormality, systemically unwell

25

Complications of orbital cellulitis - how to diagnose

Subperiosteal abscess
Orbital abscess
(CT or MRI of orbit)
Extraorbital extension

26

Management of orbital cellulitis

Urgent referral to ophthalmology
IV antibiotics: Cefotaxime IV 50mg/kg up to 2g, 8-hrly 3-14 days (depends on response)
Followed by:
Oral amoxycillin/clavulanate BD for a further 10 days

27

Aetiology and Pathogens likely to cause orbital cellulitis

Most commonly a complication of bacterial rhinosinusitis (though it is not a common complication) - particularly ethmoid involvement
Microbiology: strep anginosus or strep pneumoniae, staph aureus (including MRSA)

28

Epidemiology of congenital glaucoma

1/10,000 live births
bilateral in 60% *onset may be asymmetric
onset of signs and symptoms at birth in 40% (by 12m in 85%)
Usually a sporadic disease (not inherited)

29

Presentation of congenital glaucoma

chronic or intermittent tearing
photophobia
blepharospasm (involuntary tight closure of lids)
Large/asymmetrical cornea
corneal clouding
conjunctival injection
optic nerve cupping
Occular enlargement (buphthalmos)
Younger kids: more likely odema and haze, Older kids: more likely corneal and ocular enlargement

30

Management of congenital glaucoma

urgent ophthalmology referral
Medical: drops to reduce IOP
Surgical intervention (cutting of angular trabecular network to deepen angle recess or creating an opening in Schlemm's canal)
Regular and life-long follow up will be required

31

Associations with congenital glaucoma

Congenital rubella
Sturge-Weber syndrome

32

Causes of congenital cataracts

Hereditary (autosomal dominant - recessive or X-linked less common)
Metabolic disease (e.g. galactosaemia, hypothyroid)
Syndromes (e.g. T21)
Congenital infections (e.g. Rubella)
Idiopathic - esp if unilateral

33

Presentation of congenital cataract

Parents may be able to see cataract with naked eye if anterior portion
Poor vision - abnormal behaviour
Delayed development
Nystagmus or Strabismus
Photophobia
Asymmetric red refelx/leukocoria

34

Management of congenital cataract

Refer to ophthalmologist
Surgical removal based on size and effect on vision - generally try to perform within first few months of life if identified

35

Coloboma

defect in the iris which appears like a prolapsed pupil "Keyhole pupil"