Embryology of the Eye Flashcards
Where do the first formative processes of the eye originate?
The neural tube
What are the formative processes of the eyes called?
Optic vessels
From what part of the neural tube dot he formative processes originate?
The diencephalic part
Where do the optic vessels grow towards from eh neural tube?
The surface epithelium
What occurs when the optic vessels reach the surface epithelium?
?They cause one of the cells on the ectoderm to thicken, forming the lens placode
What is the lens placode?
The thickening of surface ectoderm cells caused by contact with the optic vessels
Once the lens placode is formed, what happens?
It starts to push inwards - invaginate
What happens to the optic vessel as a result of invagination?
It forms an optic cup
What is the optic cup?
It is formed by the optic vessel when the lens placode invaginates
How many layers does the optic cup form?
2
What detaches from resurface ectoderm once the 2 layer optic cup is formed?
The lens vesicle
How do vessels reach the newly formed optic cup and lens vesicle?
They pass through from a fissure in the anterior wall, forming an impression known as the choroid fissure
What is the choroid fissure?
A fissure caused by passage of vessels to the optic cup and lens vesicle
What is the normal fate of the choroid fissure?
It disappears
What happens if the choroid fissure fails to disappear?
It causes gaps in surrounding tissue known as Coloboma, these can commonly affect the iris, retina or optic disk
