Paediatric Ophthalmology Flashcards
How does Minimal Normal Visual Acuity change with age?
At what age does Visual Development occur?
Visual Development
* ‘Growth period’-from birth till around 8 years old
* Eye sight development may be affected if something happens to one or both of the eyes during the ‘growth period’ of vision.
What is Amblyopia (Lazy Eye)?
- Formal definition?
Amblyopia (Lazy Eye) = A vision impairment of one eye (also called “lazy eye”), due to abnormal communication between the eye and the brain. May develop as a result of uncorrected strabismus, cataract, or refractive errors.
- During the ‘growth period’ (or period of plasticity) of eye sight development, if the child stops using one eye for whatever reasons, the sight development can be irreversibly damaged, and the child may not develop the sight in the eye forever.
What is not “Lazy Eye” - 3 conditions often labelled as such?
What is the risk of developing amblyopia?
- Reversibility?
- Treatment?
Risk of amblyopia
- If an eye is deprived of proper vision during the ‘period of plasticity’ for longer than a week per year of age, the eye may become amblyopic.
- Safety margin of visual deprivation ONE week PER year of age
Reversibility of Amblyopia
- monocular resolution-weeks to 8 years
Treatment
- Correct the cause-media opacity, focusing problem, misalignment etc
- Occlusion/penalization
List 5 causes of amblyopia?
- Poor Focus
- Myopia (short-sightedness) Hypermetropia (long-sightedness)
- Poor Aim = Strabismus (squint)
- Esotropia/Exotropia
- Poor Clarity
How to diagnosis a squint?
4 Causes of an abnormal Brüchnër test?
- Hirschberg (torch-light) Test = Compare the location of the 2 corneal light reflections.
- Brüchnër Test = Set the hand held ophthalmoscope to ‘0’, Dim the room lights, At app. 1 meter away, Look through the peep-hole at BOTH of the eyes at the same time, Compare the colour of the red reflexes of both eyes.
- Cover Test = cover one eye and view the other
What is Leukocoria?
- 4 causes of bilateral?
- 6 causes of unilateral?
Leukocoria = an abnormal white reflection from the pupil (instead of the normal red-eye reflex).
- In brief, any time you see a white pupil, you must refer the child to an Ophthalmologist ASAP!!
What is the most common ocular malignancy in childhood?
= Retinoblastoma
- Most common ocular malignancy in childhood
- Mostly diagnosed before the age of 5 years
- 5% to 10% have a positive family history
What is this?
Congenital glaucoma (Buphthalmos)
What is Papilloedema?
- Definition?
- 6 Causes?
- Pathophysiology?
- Clinical features?
- Diagnostics?
Definition: swelling of optic disc due to elevated intracranial pressure
Aetiology
1. Hypertensive emergency
2. Idiopathic intracranial hypertension (pseudotumor cerebri)
3. Intracranial tumors (e.g., medulloblastoma)
4. Hydrocephalus
5. Cerebral abscess
6. Hypervitaminosis A
Pathophysiology: increase in cerebrospinal fluid pressure causes a disruption of the axoplasmic flow in the optic nerve.
What is a Strabismus?
- 4 Tests to screen?
- 2 Primary causes of strabismus?
- 11 Secondary causes of strabismus?
Strabismus (‘squint’) is a common childhood disorder that can cause psychosocial distress and permanent functional disability. The four tests used to screen for strabismus are:
1. the light reflex test
2. the red reflex test
3. the cover test
4. the uncover test.
Is Amblyopia a cause or a consequence of strabismus?
- Amblyopia is a recognised consequence of established strabismus (either primary or secondary).
- However, amblyopia can paradoxically also be a cause of secondary strabismus, as a degraded visual experience in one eye may result in that eye drifting out of correct alignment.
- Uncorrected refractive abnormalities, such as myopia and hyperopia, may also result in secondary strabismus via a similar mechanism.
What are the different types of strabismus?
- The most common type of strabismus involves horizontal misalignment of the eyes, although vertical misalignment also occurs.
- Ocular deviation may be manifest (tropia) or latent (phoria). Manifest ocular deviation can be present in all directions of gaze (comitant) or only present in specific directions of gaze (incomitant).
What history should be obtained for a child presenting with Strabismus (‘squint’)?
Therapeutic options for a Strabismus?
Complications of strabismus?
