|
|
|
|
11.5
|
29
|
Basement membrane of surface ectoderm intact Primary lens fibers form Trochlear and abducens nerves appear Lid fold present
|
|
|
6
|
37
|
12
|
|
Edges of optic fissure in contact
|
|
|
|
|
12
|
30
|
TVL present Lens vesicle cavity obliterated Ciliary ganglion present
|
|
|
|
41
|
12
|
32
|
Posterior retina consists of nerve fiber layer, inner neuroblastic layer, transient fiber layer of Chievitz, proliferative zone, outer neuroblastic layer, and external limiting membrane
|
|
|
|
|
17
|
32
|
Eyelids fuse (dog)
|
|
|
7
|
|
|
|
Anterior chamber beginning to form
|
|
|
|
|
12.5
|
40
|
Secondary lens fibers present
|
|
|
|
48
|
14
|
32
|
Corneal endothelium differentiated
|
|
|
8
|
51
|
|
|
Optic nerve fibers reach the brain Optic stalk cavity is obliterated Lens sutures appear Acellular corneal stroma present
|
|
|
|
54
|
|
30–35
|
Scleral condensation present
|
|
|
9
|
57
|
17
|
40
|
First indication of ciliary processes and iris
|
|
|
|
|
|
—
|
EOMs visible Eyelids fuse (occurs earlier in the dog)
|
|
|
10
|
|
|
45
|
Pigment visible in iris stroma Ciliary processes touch lens equator Rudimentary rods and cones appear
|
|
|
|
|
|
45–1P
|
Hyaloid artery begins to atrophy to the disc
|
|
3
|
12
|
|
|
—
|
Branches of the central retinal artery form
|
|
4
|
|
|
|
51
|
Pupillary sphincter differentiates Retinal vessels present
|
|
—
|
|
|
|
56
|
Ciliary muscle appears
|
|
|
|
|
|
—
|
Tapetum present (dog)
|
|
5
|
|
|
|
40
|
Layers of the choroid are complete with pigmentation
|
|
6
|
|
|
|
—
|
Eyelids begin to open, light perception
|
|
|
|
|
|
1P
|
Pupillary dilator muscle present
|
|
7
|
|
|
|
1–14P
|
Pupillary membrane atrophies
|
|
|
|
|
|
1–16P
|
Rod and cone inner and outer segments present in posterior retina
|
|
|
|
|
|
10–13P
|
Pars plana distinct
|
|
9
|
|
|
|
16–40P
|
Retinal layers developed
|
|
|
|
|
|
14P
|
Regression of pupillary membrane, TVL, and hyaloid artery nearly complete Lacrimal duct canalized
|
Table 1.2 Sequence of ocular development in the cow.
|
Ocular part or event
|
Gestational size (mm)
|
|
Lens
|
|
|
Optic vesicle
|
6
|
|
Lens placode
|
6
|
