Development of eye.

it describes the development of eye and accessory parts of the eye in details.

1. Development of eye
To MBBS 2
nd
year
Dr. Laxman Khanal
Assistant professor, department of anatomy
BPKIHS, Dharan
02-04-2017

2. Eye development : start at Day 22.
Before NT closure
-Day 25 to Day 28

3. Diencephalon
of forebrain
PAX 6
Key regulatory gene for
eye development.
Optic vesicle
Optic groove
Lens placode Optic stalkOptic cup

4. 1.Fibrous covering
2.Vascular covering (#ICC)
3.Nervous covering
Limbus
Equator

5. •Keysteps-Formationofopticvesicleandopticstalk.
•Opticvesicle/stalk–neuro-ectodermalinorigin.
•Lumenoftheopticvesicleisconnectedwiththe3
rd
ventriclethroughthe
lumenofopticstalk.

6. Astheopticvesiclecomesincontactwiththesurfaceectoderm,itinducesit
tothickenandformslensplacode(primordiumoflens),solensis
ectodermal(surfaceectoderm)inorigin.
Asthelensvesicleisbeingformed,opticvesiclebeginstoinvaginatetoform
double-layeredopticcup.Themarginsoftheopticcupgrowandenclosethe
lensvesicle.

7. Choroidalfissure
•Vascularmesoderminvadethefissure.
•Thismesodermlaterformhyaloidvessels&
vitroushumor.
•Onlytheproximalpartofthesevesselspersists
asacentralartery/veinofretina
Up to now…..
•Optic vesicle
•Optic stalk
•lens placode
•Choroidal fissure

8. DevelopmentofRetina-twolayersofopticdisc
Developmentofopticnerve-opticstalk(axonsofganglioncells)
Retinaldetachment:
Separationofpigmentepitheliumfromtheneurallayer.

9. Oraserrata
•Oraserrataisthejunctionbetween
photosensitiveandnon-photosensitive
retina.
•Liesbetweenlimbusandequatorofeye
ball.

10. Coloboma
•Failure to close choroidal fissure
•Key hole appearance in iris
•Follow AD inheritance
Retinal detachment
•Medical emergency
•Occurs between 2 layers of retina

11. Development of optic nerve
•Second cranial nerve
•Optic nerve encloses retinal vessels
•Formed by axons of ganglionic cells
•Covered by meningeal layers
•Myelinated by Oligodendrocytes
@ 7
th
week

12. Development of-
•Iris
•Ciliary body

13. Development of Iris
Epithelium: both layers of retina (ant part)
Stroma: mesenchyme
Muscles: outer layer of retina

14. Development of ciliary body
Epithelium: both layers of retina (ant part)
Stroma: mesenchyme
Muscles: mesenchyme
Aqueous humor

15. Derivatives of optic cup
•Retina
•Dilator pupillae
•Sphincter pupillae
•Epithelium of the iris
•Epithelium of ciliary body
Derivatives of optic stalk
Optic nerve

16. Anterior
segment
Posterior
segment
Lens
Anterior chamber
Posterior chamber
Canal of Schlemm
Iris

17. Mesoderm
Posteriorly
divide into two layers
Anteriorly
Vacuolization occurs
Surface Ectoderm
Double folding occurs
Development of-
•Sclera
•Choroid
•Cornea
•Conjunctiva
•Eyelids

20. Doublefoldingofsurface
ectodermgiverisetothe
conjunctivaandeyelids.

21. Surface Ectoderm
•Outer epithelium of cornea
•Conjunctiva
•Lining of eye lids
•Tarsal gland
•Eye lashes

22. Persistent iridopupillary membrane Congenital cataract
TORCH infection

23. Aniridia
Synophthalmia
or
CyclopiaLoss of midline structure
•Alcohol
•Maternal DM
•Mutation of SHH(sonic hedgehog)
•Abnormal cholesterol metabolism

24. Conclusion
•Theeyesbegintodevelopasapairofoutpocketingsoneachsideof
theforebrainatday22.
•The optic vesicles contact the surface ectoderm and induce lens
formation.
•Throughagroove(thechoroidFissure),thehyaloidartery(laterthe
centralarteryoftheretina)enterstheeye
•PAX6,themastergeneforeyedevelopment.
•Corneadevelopsfrombothectodermandmesoderm.