Paediatric ophthalmology Flashcards
Amblyopia
Decrease in best corrected visual acuity due to incomplete development of lateral geniculate nucleus and primary visual cortex and persists into post-natal period
- Unilateral amblyopia = Difference of 2 or more Snellen lines between the two eyes
- Bilateral amblyopia = Best corrected visual acuity worse than 6/12 in both eyes
Causes of amblyopia
- Strabismus
- Stimulus deprivation:
- Ptosis
- Congenital ptosis
- Capillary hemangioma
- Cataract - Refractive error
Management of congenital ptosis
Partial ptosis: leave it
Ptosis causing astigmatism and occlusional/deprivation amblyopia:
- Spectacle correction
- Lid elevation Sx (Levator muscle resection, Frontalis suspension procedure)
Capillary hemangioma
- Usually appear within first 6 months of life but decreases in size b/w 12-15 months of age (Most regress nearly completely by 5-6y/o)
- Eyelid hemangioma –> Ptosis/ Astigmatism
- Orbital hemangioma –> Compress globe, eye muscles, optic nerve
Refractive error
- Large refractive error in both eyes –> Ammetropia amblyopia
- Unequal amount of refractive error between two eyes –> Anisometropic amblyopia
- High astigmatism causing amblyopia –> Meridional amblyopia
Management of amblyopia
- Provide clear retinal image (treat underlying cause, if any)
- Identify and correct any refractive error
- Full-time spectacle wear for refractive amblyopia
- Remove obstacles in visual axis (E.g., eyelid tape with ptosis, cataract) - Correction of ocular dominance (Occlusion therapy)
GOLD STANDARD
- Patch the good eye to force fixation and usage of amblyopic eye
- 1% Atropine penalization of good eye (Blur caused by atropine fogs good eye so that fixation is switched to amblyopic eye) - Parental counselling
- Stay compliant!
- Best before 7-8y/o
Types of strabismus
Horizontal: Eso/ Exotropia
Vertical: Hyper/ Hypotropia
Torsional: Incyclo/Excyclotorsion
Assessment of strabismus
- Visual acuity assessment
- Hirschberg test/ Corneal light reflex test
- position of the corneal light reflex is evaluated - Check for pseudo convergent squint:
- Caused by skin fold that covers the medial part of eye
- Common in Asian children esp Chinese
- Nil Tx - Cover uncover test
- Patient to fixate on an object
- Cover normal eye (1-2s) and observe abnormal eye shift to midline
- Note that when you uncover normal eye, it may be turned to the same direction as the abnormal eye - Alternate cover test (Reveals latent squint/exophoria)
- EOM Mobility PE
- Stereoacuity: 3D vision - measure of how well both eyes fuse images together
- Cycloplegic Refraction
- Full eye and neurological assessment
In esotropia, corneal reflex is deviated
temporally
In exotropia, corneal reflex is deviated
nasally
In hypertropia, corneal reflex is deviated
downwards
In hypotropia, corneal reflex is deviated
upwards
Complications of strabismus
Amblyopia
Poor binocular vision
Abnormal head posture
Management of strabismus
Prescribe glasses if necessary
Treat lazy eye: patching
Orthoptic exercises
Prisms for diplopia
Strabismus surgery
Leukocoria
Presence of a “white pupil,” name given to the clinical finding of a white pupillary reflex, when the path of light is obstructed in the eye
Causes of leukocoria
Lens
- Cataract
Vitreous
- Persistent foetal vasculature
Retina
- Retinoblastoma**
- Non accidental Injury
- Coats’ disease
- Retinopathy of prematurity
- Optic disc abnormalities
- Congenital infections (Toxoplasmosis, toxocara)
Risk factors of leukocoria
TORCH infections
Family history
Prematurity
History taking for leukocoria
Prenatal and birth history
exposure to toxins (alcohol)
Exposure to medications (corticosteroids)
infections during pregnancy (TORCH – toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus)
complications during delivery
Attention should also be paid towards finding out the gestational age to assess for prematurity
Postnatal history
need for admission to the intensive care unit and prolonged exposure to oxygen therapy
developmental history of the child, looking out for a history of weight loss or failure to thrive, which may point to more systemic illnesses not excluding retinoblastoma
Family history:
retinoblastoma and other eye diseases such as retinal detachment
Drug history
Current medications, especially corticosteroid use
Social history
predisposing factors to development of toxocariasis and toxoplasmosis - exposure to pets such as dogs and cats / history of geophagia (eating of soil)
PE for leukocoria
Pupillary examination, looking out for a direct pupillary reflex and the presence of RAPD
Slit lamp examination, which can be used to detect cataracts and anterior chamber inflammation
Dilated fundus examination to look out for the status of the retina, retinal vasculature and the presence of any tumors
Extraocular motility to look out for abnormal eye movements which may be associated with retinoblastoma
Retinoblastoma
Most common intraocular malignancy in children
Usually presents before 3 y/o
Heritable (40%) and non-heritable forms
- AD
- Heritable forms usually bilateral
- a/w pineal gland tumour
Presentations of retinoblastoma
Leukocoria in 50%
Strabismus
Change in eye appearance (Heterochromia or red, painful or watery eyes)
Reduced visual acuity
Pseudosquint
Pseudohypypyon
Management of retinoblastoma
Refer to Eye and Paeds Onco
- Save life, save eye, save vision, minimise complications
Tx options
- Cryotherapy
- Photocoagulation
- Radiotherapy
- Chemotherapy
- Enucleation
- Intra-arterial chemotherapy
Genetic counselling/Screen siblings!
Causes of congenital cataracts
- Primary: Idiopathic, hereditary
- Secondary: Chromosomal, metabolic (Lowe), uterine infx - TORCHes (Toxoplasma, other agents, rubella, CMV, HSV-2), anterior segment dysgenesis, trauma (NAI), uveitis, RB, drug exposure, radiation
Management of congenital cataracts
Conservative
- Refraction, amblyopia correction
Surgical
- Lens aspiration + primary posterior capsulotomy + anterior vitrectomy: Child is left aphakic
Post op:
- Refractive correction: Glasses, contact lens (for aphakic correction)
- Aphakic glasses
- Aggressive amblyopia Mx
Why is there a need to correct amblyopia before a child turns 7/8 years old?
There is critical time frame early in life during which there is plasticity within the visual system, particularly the visual cortex
After 7/8 years old, there is no more development of the lateral geniculate ganglion and the primary visual cortex
Anisometropic amblyopia
Significance difference between both eyes for:
- hyperopia: > 1.5 Diopters
- myopia: > 3-4 Diopters
- astigmatism: > 1.5 Diopters
What is cycloplegic refraction?
A procedure using eye drops to paralyse accommodation of the better eye to accurately measure refractive error in young children
1 mm of deviation in corneal light reflex equals to
~7 degrees of squint
Concomitant strabismus
Non-muscle paralytic
Degree of deviation is constant in all directions
Types of concomitant strabismus
- Congenital/Infantile esotropia (presents before 6mo)
- Accommodative esotropia (high degree of hypermetropia, can be corrected by glasses)
- Intermittent exotropia (commonest type in sg, eye straight most of the time, but drifts out sometimes)
Incomitant strabismus
- Caused by paralysis of EOM
- Deviation worse in certain directions of gaze
Types of incomitant strabismus
- CN 4 palsy
- CN 6 palsy
- CN 3 palsy
- TED
VA assessment in Paeds
< 6 months:
- Fix + follow to objects
- Reaction to light
- Presence of nystagmus suggests poorer vision
- Objection to occlusion (cries when better eye is covered)
6 months to 2yo:
- Forced preferential looking (prefer to look at patterned bg vs plain bg)
- Teller acuity cards
- Cardiff acuity cards
2yo to 4yo: Matching
- Kay pictures
- Sheridan Gardiner
Retinopathy of pre-maturity
Presence of abnormal retinal vasculature in a child born pre-maturely
Normal retinal vascularisation on the internal retinal surface begins at the optic nerve at 16 weeks gestation and proceeds anteriorly
- Nasal retina: 36 weeks
- Temporal retina: 40 weeks
Screening for ROP
All pre-mature babies < 1500g or < 32 weeks gestation age
Complication of untreated ROP
Retinal detachment and blindness
Risk factors of ROP
Early gestational age
Low birth weight
Supplemental o2
Treatment for ROP
Laser photocoagulation
Cryotherapy
Intra-vitreal anti-VEGF
Tearing in children: possible Ddx
Sight threatening
- Congenital glaucoma
- Ophthalmia neonatorum
Others
- Hypersecretion
1. Lid (epiblepharon: in-turning of the eyelashes caused by an abnormal congenital horizontal fold of skin near the upper or lower eyelid)
2. Lashes (trichiasis/distichiasis)
-> causes irritation
3. Allergic conjunctivities
- Obstruction: Congenital nasolacrimal duct obstruction
Congenital glaucoma triad
Blepharospasm (squeezing of eyes)
Epiphoria (tearing with tears rolling down cheeks)
Photophobia
Treatment of congenital glaucoma
Mainstay is surgery (goniotomy, trabeculotomy, glaucoma drainage shunt) as response to medical treatment is poor
Ophthalmia neonatorum
Neonatal conjunctivitis within the first 28 days of life
Causes of ophthalmia neonatorum
Chemical: <24h after birth
Neiserria gonorrhoea: 3-5 days
Chlamydia trachomatis: 5-14 days
HSV: 1-2 weeks
Complications of ophthalmia neonatorum
2’ to neiserria gonorrhoea:
- penetrates intact corneal epithelium and leads to corneal perforation
- meningitis, arthritis, septicaemia
- IV ceftriaxone
2’ to chlamydia trachomatis
- pneumonitis, otitis media
- PO erythromycin
Important ix for ophthalmia neonatorum
Conjunctival swab for microbiological diagnosis
- Neiserria gonorrhoea: IV ceftriaxone
- Chlamydia trachomatis: PO erythromycin
Management of ophthalmia neonatorum
- Comanage with Paeds ID
- Counsel mother to start broad topical spectrum abx (tobramycin)
- Teach mother to toilet eye (hourly saline lavage)
- Follow up daily until cultures are available
- Treat mother and child
What valve is commonly involved in nasolacrimal duct obstruction (NLDO)?
Valve of Hasner
- commonly closed at birth
- opens by 1st month of life
Failure to open can lead to excessive tearing in that corresponding eye
How to diagnose NLDO?
Fluorescein dye disappearance test
- Apply the dye in both eyes
- Wait for 5 minutes and check both eyes
- +ve test: fluorescein dye is still noted in the eye
Management of NLDO
Conservative
- Crigler massage (massage from medial canthal region to nose)
- Eye toilet
- KIV topical abx if infected
95% spontaneously canalise at 12 months
Surgical (if unresolved at 12 months)
- Syringing + probing
- KIV repeat in 6 weeks with intubation (Crawford tube) or balloon dilation if initial probing fails
Allergic conjunctivitis
refer to red eye
Orbital cellulitis in Paeds
Suspect in a child with
- Unilateral proptosis
- Redness
- Pain
Signs of orbital cellulitis
Similar in adult
Most common cause of orbital cellulitis
Sinusitis
Consider other causes:
- insect bites
- stye/chalazion
- teeth extraction/cavity
- infected sebaceous cyst
Congenital/Infantile esotropia
- Usually appears within first 6 months of age
- Large angle
- Can develop amblyopia in 50% of patients
- Requires early surgery before 12-18 months of age
- Poor prognosis for high grade of stereopsis (depth perception)
Accommodative esotropia
Children are far-sighted (hyperopic)
Acquired between 6 months to 5 years of age
- Fully accommodative: ET resolves fully with fitting of hyperopic glasses
- Partial accommodative: Residual ET after correction of hyperopia; surgery is required to correct remaining angle of deviation
High accommodation convergence : accommodation (angle of deviation at near is larger than angle of deviation at a distance: bifocal glasses with line bisecting pupils)
Intermittent exotropia
*most common strabismus
Acquired between 2yo-8yo
Present more frequently when child is tired/day dreaming
Good stereopsis + binocular fusion when eye is aligned
Surgery indicated if:
- Increase frequency of deviation
- Increase angle of deviation
- Asthenopia
- Diplopia
- Loss of stereopsis
Management of strabismus
Prescribe glasses as needed (accommodative ET)
Treat amblyopia
Orthoptic exercises
- convergence exercises (intermittent EXT)
Prism glasses to relieve diplopia
Strabismus surgery
Treatment of myopia in Paeds
- Lifestyle modification:
- encourage good near reading habits, increase outdoor time - Atropine
- stepwise increase in concentration depending on response (0.1% -> 0.2% etc) - Spectacles
Interpreting glasses prescription
Sphere:
(-) means myopic
(+) means hyperopic
higher the number after the minus/plus, the more myopic/hyperopic you are
UNIT: DIOPTERS
Cylinder:
If a number is present, means have astigmatism
- higher the number, stronger the astigmatism
(-): near sighted astigmatism
(+): far sighted astigmatism
If got astigmatism means will have to comment on axis. (if no astig then no axis)
Axis:
- Axis at 90 degrees means with the rule astigmatism
- Axis at 180 degrees means against the rule astigmatism
