Oc. Manifestations - Week 4 Flashcards
Prevalence of ocular congenital disorders in Aus?
Rare: less than 1.5% of congenital affect the eye
Male: 0.06%, female: 0.04% total: 0.05%
Describe the 5 types of congenital disorders which affect the eye.
- Phakomatoses:
- nuero-cutaneous syndromes of ectodermal origin
- most common manifestation in children = skin lesions - Chromosomal:
- Chrom. or minor gene sequence anomalies - Infections:
- infectious agents affect foetal development - Drug embryopathy:
- maternal drug use affect foetal development
Other:
- cause not determined
List 3 of the most common Phakomatoses/neuro-cutaneous disorders [not from slides, from own study]
- Tuberous Sclerosis (TF)
- Neurofibromatosis (NF): types 1 and 2
- Sturge-Weber syndrome [important one]
Can Phakomatoses cause tumours?
Yes. Can cause benign congenital tumours (I.e birthmarks)
Can Phakomatoses be sporadic or are they only inherited?
They can be both sporadic or inherited
- but they are mostly inherited
Which types of congenital eye disorders are ALWAYS acquired?
Infections and Drug embryopathy
Define Sturge-Weber syndrome:
A sporadic congenital neuro-cutaneous disorder characterised by a port-wine stain affecting the skin in the distribution of the ophthalmic branch of the trigeminal nerve (CNV)
What 3 parts of the body can be affected by Sturge-Weber’s syndrome?
- Skin and/or
- Eye and/or
- CNS
How can Sturge-Weber affect the skin?
Port wine stain (PWS) - capillary hemangioma, cutaneous naevi
How can sturge-Weber affect the eye?
Choroidal hemangioma, glaucoma
Define hemangioma
A benign tumour of blood vessels, often forming a red birth mark
Briefly describe the process of eye embryology (day 19 to day 36)
Day 19: Neural plate forms neural groove
Day 20: Neural folds grow towards each other to form neural tube
3.5wk/~Day 24: Neural tube closes
Day 27: Optic vesicle outgrowth from each side of forebrain
Day 27: Surface ectoderm pushes into optic vesicles and becomes LENS PLACODE, also optic cup forms
Day 36: Lens placode gets suspended from neural ectoderm into eye
How do optic vesicles form, and when do they form? (embryology). What is this stage of embryogenesis known as?
Day 25: Indentations (optic pits) form in neural tube and then expand to form sac-shaped extensions (optic vesicles)
Known as Formative Stage 1
How does embryology form fissures for the hyaloid artery and vein to pass through?
At day 35 (Formative Stage 3): Closure of optic stalks form a cleft called fetal (choroidal) fissure which the hyaloid artery and vein pass through
Are facial port wine stains always indicative of Sturge-Weber’s syndrome?
No. Commonly, facial PWS is not indicative of Sturge-Weber’s.
However, if you have Sturge-Weber’s, you will have a PWS
What is a port wine stain (PWS)?
It’s a discolouration of the skin caused by vascular anomaly, usually on the face
Which location of Port-wine Stain is associated with increased risk of Glaucoma? Where would this Glaucoma most likely develop?
When PWS is distributed along the upper trigeminal nerve on the face (greatest risk if affecting upper eyelid)
- 1/3rd of these patients develop glaucoma
Glaucoma is most likely to be ipsilateral to the PWS
Define Angioma
An abnormal growth/tumour caused by the dilation or formation of new blood vessels
What causes the port wine stain (PWS) in Sturge-Weber?
is caused by excess capillaries just below the skin’s surface, or from capillary hemangioma (benign tumour of blood vessels)
Where can angioma occur in Sturge-Weber?
- lymphatic (lymphangioma)
- vessel walls (hemangioma)
- tissues surrounding the vessels (telangiectasia, ectasia)
Define Ectasia
dilation or distention of a tubular structure
Describe the histopathology of lid angiomatosis
- many capillaries
- thickened vascular endothelial cells
tumour is usually benign
SW syndrome: What happens if there is a anomalous vascularity at the canal of schlemm?
Lead to congenital glaucoma
List eye-related common pathology for Patau’s syndrome
- coloboma: often assoc. with undifferentiated mesenchyme
- microphthalmos
- glaucoma
- retinal dysplasia
- corneal dysgenesis