Ophthalmology SC009: Eye Problems In Children Flashcards
Common eye problems in children
- Refractive error
- Amblyopia
- Squint
- Tearing
- Ptosis
- White reflex (Leukocoria)
History taking in paediatric ophthalmology
- Birth history
- Gestation
- Birth weight (esp. important in Retinopathy of prematurity) - Ocular history
- Previous surgery
- Corrective lens use
- When started to use glasses (clue to whether they have developed amblyopia or not) - Family history
Development of visual system
- Visual structures fully present at birth but ***not yet mature
- Axial length:
—> At birth: 16-17 mm (quite short eyeball)
—> 1 year: 20-21 mm
—> Adults: 23-25 mm - ***Hypermetropic (i.e. Long sighted)
- Images are unclear
—> ∵ yet to learn to focus with ciliary muscles
—> even if clear image projected onto retina —> fovea and visual parts of brain are too immature to develop a clear image
—> crucial period where ***amblyopia can develop - VA development:
—> VA: 20/600 (for newborns)
—> slowly develop until 8 years old —> plateau
Fixation reflex
- Poorly developed at birth
—> inability to carry out pursuit movements (following object) in the first few weeks - 2-3 weeks: follow light ***uninocularly
- 6 weeks - 6 months: follow light ***binocularly
- Convergence develops at 1 months and established at 6 months
- Accommodation lags behind (∵ delay in development of ciliary muscles) parallels with convergence by 6 months
Binocular stereoscopic vision (BSV)
Provide proprioception, stereopsis (perception of depth)
- develops at 4 months
- peak at 2 years
- well developed by 4 years
- plateau by 9 years
—> BSV will be compromised if amblyopia develops before 9
Electrophysiological studies show infants can appreciate slight retinal disparities by 2-5 months, little is known about stereo between 6 months - 3 years, accepted that stereoacuity (3D) improves until 9 years
Generally: sensitive period = 2 years
Pre-verbal VA test
Baby:
1. **Response to light
- pupil responses, steady fixation (following torch)
2. **Fixate and follow (>=3 months)
- CSM (Central (no eye deviation), Steady (no nystagmus), Maintenance (fixated and move with object))
3. ***Objection to occlusion
Older baby:
1. ***Preferential looking
- Keeler-Teller acuity card
- Cardiff acuity card
2. Lea grading
3. 100 and 1000’s
Toddler age (2-3 years):
1. Name pictures
- ***Kay pictures (with keycard)
- Ffooks symbols
- Lea symbols
Schooling years (>=4 years):
1. Matching tests
- ***Sheridan-Gardiner (with Keycard)
—> HOTV
—> HOTVAUX
Other tests:
- Visual evoked potential
- Optokinetic response
Eye examination in children
- Need to do refractive error frequently (∵ eyeballs constantly growing —> refractive error constantly changing)
- Give ***mydriatics to dilate pupil for more accurate refractive error measurement (∵ strong ciliary muscles —> very strong accommodation reflexes —> produces inaccuracies in refractive error measurement —> overestimation of myopia)
—> Atropine / Cyclopentolate / Tropicamide
—> for up to 5 years old - IOP measurement: contact type
- Slit lamp: anterior + posterior segment examination
- Fundal examination
- ***Prism cover test (distance + near)
- diagnose + determine level of squint
Amblyopia (弱視)
Functional ↓VA caused by ***abnormal visual development early in life
Abnormal visual development:
- ↓ VA
- Unilateral / Bilateral
- **Apparent normal physical examination (i.e. normal structures)
- **Brain do not develop the eye(s)
Causes:
1. Poor focus
- **Anisometropia (difference in refractive error between 2 eyes, e.g. one eye with severe long / short-sightedness)
- **Ammetropia (significant refractive error in both eyes)
-
**Myopia and **Hypermetropia (most common)
- Myopia: Eyeball too long, image focused in front of retina
- Hypermetropia (Hyperopia): Eyeball too short, image focused behind retina - Astigmatism
- Cornea curvative not uniform - ***Strabismus
- Poor aim of vision from deviated eye
- Eso/exo, hyper/hypotropia (more common in horizontal than vertical) - ***Deprivational
- Poor image reception (image blocked e.g. by corneal opacity, complete ptosis, congenital cataract)
Management:
1. Correct underlying cause
2. Correct refractive error if any
3. Patching good eye —> force bad eye to look
- Treatment depends on plasticity of visual system —> timing is crucial —> need to do before 9 years (after that not salvageable)
- NOT patch all day —> ***Deprivational amblyopia —> 6 hours max
- Detect + treat early
Strabismus
Normal retinal correspondence:
- Require both eyes
- Fovea have a common visual direction
- Retinal elements **nasal to fovea of one eye correspond to retinal elements **temporal to fovea of other eye
- Bifoveal fixation is basic requirement for stereopsis (3D) (i.e. if amblyopia in one eye stereopsis is lost)
Strabismus:
- Ocular misalignment
- Brain will suppressed image from misaligned / deviated eye
Types:
1. Eso (convergent squint)
2. Exo (divergent squint)
- Tropia (manifest squint)
- one eye deviated when focus on object - Phoria (latent squint)
- only occur under some conditions e.g. tiredness
- eye is mainly straight
Signs:
- **Abnormal head posture (head tilt, chin up/down, face)
- **↓ VA (NOT Diplopia (only in adults))
Investigations:
1. **Hirschberg reflex
2. **Cover test (= Cover and Uncover test)
—> Cover and Uncover component (look at uncovered eye: detect Tropia)
—> Alternate cover test (look at uncovered eye after covering: detect Tropia + Phoria)
- objective dissociative test to elicit presence of tropia / phoria
- information gained:
—> type / size
—> speed of re-fixation / rate of recovery (determine severity)
Management:
1. **Optical correction (∵ can be caused by refractive error)
2. **Orthoptic exercise (convergent / divergent exercise)
3. **Occlusion (depend on type of strabismus)
4. **Operation (severe, frequent, amblyopia, ↓ VA, ↓ stereopsis)
Adult squint:
1. From childhood
2. Nerve palsy (e.g. CN3, CN6 palsy)
3. Muscle problems (e.g. Thyroid eye disease: Swelling in EOM, tight + fibrotic muscles, usually inferior rectus muscle affected first —> difficulty upgaze since cannot relax)
4. Trauma (e.g. orbital fracture)
Classification of squint
- Concomitant
- Eyes maintain a **fixed angle of deviation in all directions of gaze
- Majority of squints seen in **childhood - Paralytic / Incomitant
- Paralysis of one / a group of eye muscles
- Angle of deviation **changes with direction of gaze (e.g. CN6 palsy causing only Abduction gaze problem)
- Mainly seen in **adults
Pseudosquint
- Flat nasal bridge
- Epicanthic fold
- Central corneal reflex
- ***Negative cover test
***Epiphora
Excessive tearing, common in children
Causes:
1. ↑ Production
- ***Epiblepharon (vs Entropion)
—> redundant skin below lashes —> push lash against cornea —> irritation of cornea —> tearing
—> usually resolve itself
—> operation for severe case
- ↓ Drainage
- ***Failure of canalisation of nasolacrimal duct (e.g. Congenital nasolacrimal duct obstruction)
—> may canalise itself
—> operation after 1 year old if not canalise itself
—> complication: eye infection
Management:
- **Probing + **Irrigation with antiseptic solution through inferior punctum and canaliculus
—> confirm patency of system
—> can put in balloon stent to expand pathway
Important DDx: **Congenital glaucoma (can be blinding)
- Lacrimation
- Photophobia
- **Blepharospasm
- **Hazy cornea
- **Buphthalmos (large eyeball ∵ ↑IOP)
- ***Rapidly progressive myopia (∵ long eyeball)
Ptosis (Droopy lid)
Causes:
1. Congenital (common in children)
2. Neuromuscular
3. Trauma
4. Syndromal
Signs:
- Chin up posture
Complication:
- Amblyopia
Management:
- Treat cause
- Observe
- Operate if vision threatening
- Surgery —> Frontalic sling (complications: Lagopthalmos, Corneal exposure, Corneal infection)
DDx:
Marcus Gunn jaw-winking:
- when using mastication muscles —> eye will blink (∵ aberrant connection between CN5, Levator palpebrae superioris)
Chalazion
Chronic lipogranulomatous inflammation within meibomian gland
Treatment:
1. Warm compression
2. Antibiotic ointment
3. Incision and curettage
Leukocoria
Red reflex:
- comes from retinal + choroidal vascularisation
- anything blocking visual pathway —> loss of red reflex —> white pupil (Leukocoria)
Leukocoria:
- must do dilated fundoscopy exam
- referral to ophthalmologists ASAP
Causes of Leukocoria:
1. Congenital cataract
2. **Old vitreous haemorrhage (check for Non-accidental injury (NAI) e.g. Shaken baby syndrome)
3. Persistent hyperplastic primary vitreous (PHPV, congenital condition)
4. Uveitis (Severe vitritis)
5. Coat’s disease (∵ Exudative retinal detachment)
6. **Retinopathy of prematurity (aka Retrolental fibroplasia) (∵ Tractional retinal detachment)
7. Retinal detachment
8. **Colobomata (∵ lack of pigmentation in choroid / RPE —> see sclera only)
9. **Toxocariasis (TORCH infection) (∵ Granuloma formation)
10. Retinal dysplasia
11. Retinal tumours (Retinoblastoma) (must rule out)
