P1: Ocular Embryology & Development

Neural crest

Corneal stroma and endothelium

Neural crest

Uveal stroma and melanocytes

Neural crest

Ciliary muscle

Neural crest

Much of the sclera

Neural crest

Connective tissue of lids, conjunctiva, orbit

Neural ectoderm

Neural retina

Neural ectoderm

Retinal pigment epithelium (RPE)

Neural ectoderm

Optic nerve fibers

Neural ectoderm

Ciliary body epithelium

Neural ectoderm

Iris epithelium

Neural ectoderm

Iris sphincter and dilator muscles

Surface ectoderm

Lens

Surface ectoderm

Corneal epithelium

Surface ectoderm

Eyelid epithelium and cilia

Surface ectoderm

Meibomian, Zeis, and Moll glands

Surface ectoderm

Nasolacrimal duct lining

Mesoderm

Vascular endothelium

Mesoderm

Striated muscle cells

Optic vesicle

Forms the optic cup and optic stalk

Optic cup outer layer

Retinal pigment epithelium

Optic cup inner layer

Neural retina

Optic fissure

Entry point of hyaloid artery

Hyaloid artery

Forms posterior tunica vasculosa lentis

Hyaloid artery branches

Form anterior tunica vasculosa lentis

Lens vesicle

Derived from surface ectoderm

Primary lens fibers

From posterior epithelial cells

Secondary lens fibers

Elongate around embryonic nucleus

Induction

Developmental influence of one tissue on another

Mesenchyme

Source of orbital connective tissues

Foveal maturation stage 1

Displacement of inner retinal layers

Foveal maturation stage 2

Migration of photoreceptors centrally

Foveal maturation stage 3

Maturation of cones

Neural retina layers

Matrix, Mantle, Marginal

Henle’s fiber layer

Formed by oblique cone inner fibers

Müller cells

Provide scaffolding in retinal development

Choroid

Develops from mesenchyme contacting RPE

Bruch’s membrane

Develops in 4th month

Ciliary processes

Derived from optic cup folds

Ciliary muscle

Derived from neural crest

Trabecular meshwork

Derived from neural crest

Aqueous humor

Starts forming 4

Corneal stroma

From second wave of neural crest mesenchyme

Corneal endothelium

From first wave of neural crest mesenchyme

Bowman’s layer

Secreted by epithelial cells and fibroblasts

Sclera

Develops anterior to posterior from limbal mesenchyme

Optic nerve

From optic stalk

Myelination

Begins at lateral geniculate nucleus

Myelination

Reaches lamina cribrosa by 1

Lacrimal gland

Fully developed by 3

Fixation

Starts at 1 month, completed by 6 months

Macula

Fully developed by 4

Binocular vision

Present by 6 months

Anterior chamber

Shallow at birth

Lens at birth

Spherical with infantile nucleus

Retinal vessels

Derived from hyaloid artery branches

Retinal vascular development

Nasal before temporal

Vitreous

Primary from mesenchyme; secondary from retina

Tertiary vitreous

Zonule fibers between lens and ciliary body

Eyelid fusion

Protects eye from keratinization

Eyelids

Separate in sixth month via desmosome breakdown

Orbit

Fully developed by age 16

Eyeball

Reaches adult size by 7

Cornea

Reaches adult diameter by 2 years