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