Lecture 14: Eye Development Flashcards
When is the critical period for fetal eye development?
Weeks 4-8
What embryonic layers give rise to the eye?
Neuroectoderm
Surface ectoderm
Mesoderm/Neural Crest
What part of the brain does the eye originate from?
Diencephalon
What do the rims of the optic cup give rise to?
Iris and ciliary body
What muscles are the only muscles in the body to arise from neuroectoderm?
Dilator and Constrictor pupillae muscles
What embryonic layer gives rise to the stroma of the iris?
Neural Crest
What embryonic layer gives rise to the epithelium of the iris and the ciliary body?
Neuroectoderm
What embryonic layer gives rise to the smooth muscle cells of the ciliary body?
Mesoderm
What congenital disorders can predispose a patient to having separation of the pigmented and neural retina?
Down’s syndrome
Marfan’s syndrome
Redevelopment of the intraretinal space comes from separation of what layers?
Neural retina (inner layer) and pigmented retina (outer layer)
What is aniridia?
What can cause it?
Lack of iris tissue
- Defects in the Pax6 gene
- Glaucoma, cataracts, other eye abnormalities
Arrested development of what optic structure during the 8th week can result in aniridia?
Rim of optic cup
What embryonic layer gives rise to the lens of the eye?
Surface ectoderm
What structures of the lens are responsible for its transparent nature?
Primary lens fibers - columnar epithelium with dissociated nuclei
What optic structure do cataracts affect?
Lens
Maternal rubella infection between 4-7 weeks gestation can have what effect on fetal eye development?
Congenital cataracts (vulnerable lens development)
Congenital glaucoma
Also can be caused by genetics, rubella virus, radiation, and enzyme deficiency
A 3 week old patient presents with congenital cataracts. He is being breastfed. What is the most likely diagnosis?
Congenital Galactosemia
-Accumulation of galactose from milk because of enzyme deficiency