The document summarizes the development of the eye from early embryogenesis through birth. It discusses the formation of the three primary germ layers - ectoderm, mesoderm, and endoderm - and how they give rise to the different tissues of the eye. Key stages of eye development are described from 3-5 months of gestation. The retina, lens, vitreous humor, choroid, sclera and other ocular structures develop from specific germ layers and their precursor tissues like the neural crest.

1. Rajvin Samuel Ponraj

2. Embryogenesis : Organisation and development of the primary layers of the developing embryo After fertilization - sequential formation of three cell masses

4. Organogenesis: process in which segregatory cells become rudimentary organs

5. Derivatives of embryonic tissues Neural Crest

6. Neural crest Corneal keratocytes, Cornea endothelium Trabecular meshwork, Stroma of the iris and choroid, Ciliary muscle, Fibroblasts of the sclera, the vitreous, and the optic nerve meninges., Extraocular muscles, Subepidermal layers of the eyelids.

7. Surface ectoderm lens the lacrimal gland the epithelium of the cornea conjunctiva epidermis of the eyelids

8. Neuro ectoderm optic vesicle and optic cup Retinal pigment epithelium Ciliary epithelium Iris muscles optic nerve fibers and glia.

9. Mesoderm Vitreous Extra ocular & lid muscles Orbital and ocular vascular endothelium

10. 3 to 4 week stage of embryo

11. 2 nd month stage of embryo

12. j 3 rd month stage of embryo

13. 4 th month stage of embryo

14. 5 th month to birth

15. At birth : Anterior – posterior diameter : 16.5 mm Anterior chamber – shallow Lens - spherical Cornea diameter = 10 mm Orbit is divergent to 50 degrees Myelination occurs till lamina cribrosa Retina except macula is fully differentiated and formed

16. Post natal period : Fixation completed by 6 months Macula formed by 6 months Steropsis and accomadation by 6 months Cornea reaches adult size by 2 years Lens develops throughout life

17. RETINA It develops from the optic cup. The outer layer of the optic cup is the pigment layer. The neural layer is formed from the inner layer of the optic cup.

18. MACULA It develops as a result of localized increase of superimposed nuclei in the ganglion cell layer, lateral to the optic disc.

19. Optic nerve Develops from glial cells of neuro ectodermal cells and axons fron ganglion cells with meningeal coverings forming the optic nerve sheets

20. Lens The posterior wall begin to elongate anteriorly and form long fibers that gradually fill the lumen of the vesicle. The secondary lens fibres start from equator region elongate towards anteriorly and soon detach to form the next lens fibre layer

22. Migration of neural crest cells 1 st wave – corneal and trabecular endothelium 2 nd wave - corneal stroma 3 rd wave - Iris stroma

23. Vitreous Primary vitreous Secondary vitreous Tertiary vitreous

24. SCLERA : This tough outer fibrous coat is formed from the condensation of the mesenchyme around the optic cup CHOROID: This inner vascular layer is formed from the mesenchyme surrounding the optic vesicle.

25. Ciliary glands and eyelashes develop as outgrowths of epithelial buds Eyelid develop from surface ectoderm Lacrimal glands develop as ectodermal buds superolaterally into mesenchyme

26. Lacrimal sac and nasolacrimal duct develop from ectoderm - nasolacrimal furrow which gets burried into a cord

27. Summary of various part of the eye ball. Part Derived from Lens Surface ectoderm Retina Neuroectoderm (optic cup) Vitreous Mesoderm Choroid Mesoderm (infiltrated by neural crest cells?) Ciliary body Mesoderm Ciliary muscles Mesenchymal cells covering the developing ciliary body (neural crest) Iris Mesoderm Muscles of the iris Neuroectoderm (from optic cup) Sclera Mesoderm (infiltrated by neural crest cells?) Cornea Surface epithelium by ectoderm, substantia propria and inner epithelium by neural crest Conjunctiva Surface ectoderm Blood vessels mesoderm Optic nerve Neuroectoderm. Its covering (pia, arachnoid and dura) are derived from mesoderm

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