Development

Question 1

Parts of the supportive fibrous structural layer

Answer 1

Sclera and Cornea

Question 2

Parts of the nutritive vascular layer (uveal tract)

Answer 2

Choroid, Ciliary muscle and body, Iris (sphincter pupillae and dilator pupillae)

Question 3

Parts of the Sensory Nervous layers (retina)

Answer 3

RPE- retinal pigmented epithelium, neuronal layer. Has multiple subparts (optic part, ciliary part, iridial part, optic disk, macula)

Question 4

What are the 3 layers of the ectoderm?

Answer 4

Surface ectoderm, Neural tube (neuroectoderm), Neural crest cells

Question 5

What are the derivatives of the Surface ectoderm?

Answer 5

Lens, 
external corneal epithelium, 
conjunctiva, 
dermis of eye lids, 
lacrimal apparatus

Question 6

What are the derivatives of the neural tube?

Answer 6

The optic nerve and retina, iris pigmentation and musculature (including pupillary membrane), and the ciliary body

Question 7

What are the derivatives of the neural crest cells?

Answer 7

mesenchyme which differentiates into the CNs to the orbit (except Optic n)…so 3, 4, 6
sclera, choroid, ciliary muscle, fibrous CT of iris, endothelial and stroma layer of cornea, and tarsal plates of the eyelids

Question 8

What are the derivatives of the mesoderm?

Answer 8

vasculature and extraocular musculature

Question 9

What’s significant about day 18?

Answer 9

ectoderm begins to fold inward to form the neural groove → neural tube (neuroectoderm).

Question 10

What’s significant about day 22?

Answer 10

optic grooves begin to differentiate out of the neural folds (neuroectoderm) of the forebrain,

Question 11

What’s significant about day 24?

Answer 11

neural tube is closed and the optic vesicle begins to grow toward the surface ectoderm

Question 12

What’s significant about day 29?

Answer 12

distal portion of the optic vesicle expands at the edges while the tip begins to invaginate, developing into the optic cup

Question 13

What’s significant about day 33?

Answer 13

This retinal fissure (linear groove) will close up around the blood vessels

Question 14

A rubella infection can result in:

Answer 14

cataracts (4-7wk), congenital glaucoma,

Question 15

Congenital glaucoma due to non-infectious causes is mainly caused by

Answer 15

mismatch between humor production and drainage can lead to abnormal intraocular pressure. Generally the result of abnormal development of the scleral venus sinus

Question 16

Genetic mutations mainly cause which eye development pathology?

Answer 16

Cataracts, microphthalmia/anophthalmia

Question 17

If a persistent pupillary membrane doesn’t atrophy, what is the tx?

Answer 17

surgery or laser treatment

Question 18

Two possible causes of congenital ptosis of the eyelid

Answer 18

1. failure of normal development of the levator palpebrae superioris
2. superior rectus development if the superior branch of the oculomotor nerve is compromised

Question 19

Etiology of detachment of retina?

Answer 19

inner/outer layers of optic cup fail to fuse due to differential growth rates, often correlated with down syndrome and marfan’s. Also, trauma.

Question 20

What is a coloboma?

Answer 20

if retinal (optic) fissure fails to close, leaving a gap in the eye structures, including but not limited to the retina and iris

Question 21

What do lacrimal glands develop from and when are tears first secreted?

Answer 21

bud off surface ectoderm and secr tears at 6wks.