Peads - Anterior Segment - Alistair Flashcards
what is a coloboma?
failure of fetal fissure to close (at around 4-5 weeks)
What anterior segment developmental anomalies are there?
- Coloboma
- Albinism
- Aniridia
- Glaucoma
- Anterior seg dysgenesis
Many of these are associated with glaucoma.
What are examples of anterior dysgenesis?
- Posterior embryotoxon
- Axenfeld-rieger syndrome
- Sclerocornea
- Peters anomaly : corneal opacity and sticks to the iris
What defect causes Rieger’s anomaly?
Defect of the neural crest
a child with Reiger’s is at a high risk of what disease?
glaucoma
What are the signs of Rieger’s anomaly?
- Facial formation problems
- Iris abnormalities - strand of iris stuck to cornea + posterior embryotoxon, iris stroma hypoplasia (multiple pupils)
What are signs of peters anomaly?
Strands of the iris which will stick to corneal opacity (cataract)
How do we measure IOP in children?
iCare.
What is a albinism neuroectodermal defect?
disorder of the neuroectoderm
The two layers behind the iris.
what is the colour of the iris in albinism?
any colour- translucent
Where does the colour of the iris come from?
iris stroma
This is why in Horner’s syndrome you get heterochromia as the pigment cells have been effected.
What other signs do albinism px have?
- Fovea hypoplasia
- Strabismus
- complete crossing of fibres at the chiasm (decussation)
- Nystagmus
What is aniridia and how does it come about?
complete or partial loss of iris
Non genetic : Signs of kidney tumour !!
Genetic : dominant gene
What are px with aniridia risk of? (3)
- Glaucoma (50%)
- Ectopia lentis (lens is displaced downwards)
- Keratopathy : superficial neovas (progressive)
What are the consequences of anterior segment development anomalies?
- Vision
- Glaucoma
- Cataract
What are the non specific consequences of reduced vision?
strab and nystagmus
Why may the cornea or the eyeball be a small size?
- Due to maldevelopment
- Shrinkage following an infection or trauma
What might the cornea or the eyeball be big size?
- Maldevelopment
- Glaucoma (primary or secondary type)
what is the normal cornea diameter??
11.5 (+ or - 0.5mm)
What cause light sensitivity?
- Pigmentation : being blonde / albinism
- Anterior segment disorders
- Retinal conditions (achromatopsia and retinitis pigmentosa)
- CNS : meningitis and migraine
why do anterior segment disorders cause photosensitivity in a child?
light scatter
What is photosensitivity a first sign for?
Meningitis
What is buphthalmos?
This is when the eyeball is bigger than normal, can be caused by glaucoma
What are the two classifications of glaucoma?
Primary
Secondary
What causes primary glaucoma?
- Infantile / congenital
- Juvenile
What causes secondary glaucoma?
- Anterior segment dysgenesis
- Ocular disease and its treatment
- Inflammatory causes such as uveitis
- Chromosomal disorders such as downs syndrome
- Other : there is loads
What are the signs of infantile / congenital glaucoma?
There are breaks in the descement’s membrane due to forceps injury’s
Is infantile glaucoma bilateral or unilateral?
It can be both
What are the symptoms for infantile glaucoma?
photophobia
signs of infantile primary glaucoma?
- Red eye
- Enlarged cornea
- Corneal clouding
CAN BE V DIFFICULT TO SPOT
How do we treat infantile primary glaucoma?
- Surgically for the glaucoma
- treat refractive error
- Amblyopia therapy
ocular associations of cataract? (specific)
anterior segment dysgenesis
ocular associations of cataract? (non-specific)
microphthalmos
nystagmus/strabismus –> due to low vision
What causes cataract in paeds?
sporadic or inherited
What are systemic associations on cataract?
- Intrauterine infections ; toxoplasmosis / RUBELLA
- Metabolic : DIABETES and galactosemia
- Dermatological : atopy. SKIN PROBLEMS
- Drugs / treatment : steroids
- Chromosomal : downs
- Renal
- Musculoskeletal
- CNS and hearing
- Birthweight
Why do you get cataract with atopy(dermatological diseases)?
The intraocular lens is ectodermal (LIKE the skin)
What is amblyopia caused by?
Obstacle to the visual development. Especially one eye
Does cyls causes amblyopia in babies? why/why not?
NO - they are going through emmetropisation
How do we manage unilateral cataract?
- Operate before 9-10 weeks for function
- Patching post operative
- Optical correction post operative
why are IOLs in infancy a controversial opinion?
risk of glaucoma is v high
How do we manage bilateral cat?
- Do surgery when opacity is interfering with vision
- post op refractive error correction (CLs, glasses)
What complications can occur due to bilateral surgery?
- Amblyopia
- Glaucoma
- Capsular opacification
- Infections
What is ectopia lentis?
This is a lens that is not the correct place
What are the ocular associations for ectopia lentis?
- Anterior segment dysgensis
- glaucoma
- surgical trauma
What are the systemic assiocations for ectopia lentis?
- MARFANS syndrome - connective tissue disorder
- Homocystinuria - cardiac abnormalities
- Weill-marchesani - short stubby fingers
How can we diagnose ectopia lens?
- unstable refraction
- Iridodensis (wobbly iris)
- Stretched zonules (Direction can indicate th aetiology)
What is anterior uveitis in childhood associated with?
- Juvenile arthritis ; px is normally asymptomatic, so they need to be screened
- Idiopathic
- Sarcoidosis - inflammatory disease
- TB
- Behcet’s disease - Blood Vessels inflammatory disease
is anterior uveitis in childhood common?
no
Why does the pupil margins become irregular?
It is stuck to the lens (posterior synechiae)
What is white pupils?
leukocoria
leukocoria is indicative of….
Retinoblastoma
why do anterior segment disorders cause photosensitivity in a child?
light scatter
causes of leukocoria
retinoblastoma
coats
ROP
toxocara + toxoplasmosis
AND MORE
