Essentials of Veterinary Ophthalmology. Kirk N. Gelatt
Читать онлайн книгу.—
Table 1.2 Sequence of ocular development in the cow.
Ocular part or event | Gestational size (mm) |
---|---|
Lens | |
Optic vesicle | 6 |
Lens placode | 6 |
Optic cup and lens placode | 10 |
Separation of lens vesicle from surface ectoderm | 10 |
Primary lens fibers | 15 |
Lens vesicle cavity disappears | 24 |
Completion of lens capsule | 50 |
Secondary lens fibers | 58 |
Perilenticular vascular mesoderm | |
Extension of primary vitreous (hyaloid artery) to lens | 15 |
TVL | 33 |
Disappearance of posterior lenticular vascular network | 410 |
Disappearance of TVL | 410 |
Iris | |
Major arterial circle of iris | 90 |
Iris reaches front of lens | 200 |
Pigment in stroma | 200 |
Sphincter muscle | 410 |
Dilator muscle | 410 |
Ciliary body | |
Ciliary processes | 125 |
Ciliary processes touch lens equator | 230 |
Pars plana (distinct) | 200 |
Pars plana fully developed | 410 |
Choroid | |
Choroidal net in posterior pole | 33 |
Choroidal net throughout | 50 |
Outermost large choroidal vessels | 40 |
Choriocapillaris | 90 |
Pigmentation of choroid | 90 |
Retina – posterior third | |
Inner and outer nucleated zones | 10 |
Multilayer outer cup of optic vesicle forms single cells | 20 |
Nerve fiber layer | 20 |
Optic nerve well formed | 24 |
Inner/outer neuroblastic layers | 14 |
Transient layer of Chievitz | 14 |
Inner plexiform layer |
180
|