Term
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Definition
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Definition
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| closure of optic fissure = day ___ |
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Definition
| begins at 5 weeks, complete at 7 |
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Definition
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Definition
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| embryonic nucleus = day ___ |
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Definition
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Definition
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hyaloid artery formation = ___
hyaloid artery reabsorption = ___ |
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Definition
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| proliferative zone of neural retina = ___ |
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Definition
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Definition
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fusion of eyelids = ___
separation of eyelids = ___ |
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Definition
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Definition
| increase in number of cells |
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Definition
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Term
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Definition
| process by which a cell acquires specific functional and structural characteristics |
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Definition
| the influence a certain region of tissue or developing structure as on the development of another structures |
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Definition
| germ layer that cover organism |
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Definition
| germ layer that forms the neural tube |
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Definition
| middle embryonic layer that gives rise to CT |
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Definition
| area of cells on crest of each of the neural folds that separate ectoderm (come to lie between neural tube and surface ectoderm) |
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Definition
| neural crest cells + mesoderm |
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Definition
| the ectodermal part of the embryonic plate that will become the CNS |
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Definition
| indentation on both sides of the neural tube in the forebrain region |
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Definition
| lateral sac-shaped extension of the neural tube |
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Definition
| the thickened invagination of the optic vesicle |
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Term
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Definition
| thickening of the surface ectoderm adjacent to the optic vesicle |
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Definition
| hollow sphere composed of a single layer of cells surrounded by thing basal lamina (which will become capsule) |
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Definition
| cleft formed from the invagination of the inferior region of the optic vesicle and stalk |
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Term
| origination of the posterior tunica vasculosis lentis |
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Definition
| branches from the hyaloid vessels |
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Term
| origination of the anterior tunica vasculosis lentis |
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Definition
| branches from the annular vessel at the margin of the optic cup |
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Term
| origination of the hyaloid arterial system |
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Definition
| branch of the internal carotid artery, enters the globe through the fetal fissure |
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Term
| outer layer of the optic cup --> |
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Definition
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Term
| inner layer of the optic cup --> |
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Definition
| neural retina (-RPE of course) |
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Term
| Location of the first pigmentation in the embryo? |
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Definition
| outer layer of the optic cup (pigmentation of RPE occurs at approx week 3 or 4) |
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Term
| What neural cells are formed from the inner neuroblastic layers? |
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Definition
| ganglions, amacrines, Mullers |
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Term
| What neural cells are formed from the outer neuroblastic layers? |
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Definition
| photoreceptors, bipolars, horizontals |
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Term
| What separates the inner and outer neuroblastic layers? |
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Definition
| transient fiber layer of Chievitz |
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Term
| What are the 3 stages of foveal development? |
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Definition
1. displacement of inner retinal components to form depression (up to 15 months)
2. migration of photoreceptors toward center (increases cone packing)
3. maturation of photoreceptors - dependent on light stimulation for growth of Henle's |
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Term
| Describe lens development. |
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Definition
1. induction occurs between developing optic cup and developing lens
2. invagination of optic cups, surface ectoderm thickens and form lens placode
3. center of the outer surface of the lens placode invaginates rapidly (forms lens pit...continues to form lens vesicle)
4. posterior epi cells adjacent to future vitreous elongate to fill lumen within the lens vesicle (primary lens fibers)
5. division continues |
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Term
| Surface ectoderm gives rise to: |
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Definition
lens
corneal epi
conjunctival epi
epi of eyelids
epi of cilia
epi of meibomian glands
epi of glands of zeiss
epi of glands of moll |
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Term
| Neural ectoderm gives rise to: |
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Definition
RPE
neural retina
optic nerve fibers
neuroglia
epi of ciliary body
epi of iris
iris sphincter
iris dilator |
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Term
| Neural crest gives rise to: |
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Definition
corneal stroma-->Bowman's
corneal endo-->Descemet's
most (or all) of sclera
trabecular structures
uveal pigment cells
uveal CT
ciliary muscle
meninges of optic nerve
vascular pericytes |
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Term
| When are the ZO of corneal epi evident? |
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Definition
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Term
| Neural crest cells in the 2nd wave of mesenchyme --> _____ |
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Definition
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Term
| Neural crest cells in the 1st wave of mesenchyme --> |
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Definition
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Term
All layers of the cornea (except Bowman's) are present by ____.
Bowman's - always acellular is the last corneal layer to develop. What month? |
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Definition
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Term
| Germ layer for both iris muscles? |
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Definition
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Term
| Germ layer for the ciliary muscle? |
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Definition
| mesenchyme (like most muscle tissue) |
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Term
| Formation and reabsorption of the pupillary membrane? |
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Definition
Formed during 3rd-5th month from the 3rd wave of mesenchyme.
Degenerates months 6-8, and remnants are incorporated into the anterior border layer and collarette of the iris. |
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Term
| Origination of the anterior chamber angle structures? |
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Definition
| mass of mesenchymal cells that accumulate int he angle area that splits, going to --> iris, trabecular meshwork, atrophies |
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Term
| Describe the formation of the primary vitreous. |
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Definition
| degenerating hyaloid system, fibrils derived from developing lens/retina |
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Term
| Describe the formation of secondary vitreous. |
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Definition
| neural retina and hyalocytes from primary vitreous |
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Term
| Describe the formation of the tertiary vitreous. |
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Definition
| mesenchymal or epithelial in origin. develop zonule fibers. |
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Term
| Describe the formation of the optic nerve, the germ layers involved, and the myelinization process. |
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Definition
1. optic stalk joins optic vesicle to the forebrain
2. optic fissure develops along inferior stalk invagination, creating two layered optic stalk
3. outer layer forms the neuroglial sheath (surrounds optic nerve), and gives rise to glial components of lamina cribosa
4. inner layer cells become glial cells of optic nerves, and it also experiences programemd cell death to allow for passage of ganglion axons |
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Term
| At what age does the globe reach adult size? |
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Definition
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Term
| At what age does the orbit reach adult size? |
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Definition
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Term
List 6 structures that are not completed until after birth.
Also, what 2 other aspects are also not completed until after birth? |
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Definition
1. foveola
2. retinal vessels
3. annular muscle (of Muller, in ciliary body)
4. globe and orbit size
5. EOMs
6. nasolacrimal system.
1. optic nerve myelination
2. iris pigmentation |
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Term
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Definition
inferior defect in optic disc, retina, ciliary body, or iris due to incomplete closure of the optic fissure.
Visual problems: if they affect sensory retina and RPE, then they affect choroid |
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Term
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Definition
congenital glaucoma
--caused by increase of IOP.
Visual problems:
visual outcome is poor.
corneal edema.
nerve fiber loss from scarring.
large globes. |
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Term
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Definition
| pinpoint remnant of the hyaloid artery on the posterior surface of the lens |
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Term
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Definition
genetic, metabolic, or infectious agents (aka viral infection of mother during first trimester...especially rubella)
Visual problems: effect on VA depends on extent |
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Term
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Definition
| glial tissue that persists in the nerve head (from hyaloid system) |
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Term
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Definition
optic nerves fails to develop completely
Visual problems:
Often with a CNS developmental problem or endocrine disorder. |
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Term
| persistent pupillary membrane |
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Definition
remnant strands from a central portion of papillary membrane does not reabsorb
Visual problems:
usually no visual field complications |
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Term
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Definition
myelination of the nerve fiber layer of the retina, usually occupies a small area at the disc
Visual problems:
causes a blind spot |
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Term
| retinoblastoma Struge-Weber syndrome |
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Definition
nevus of skin (port-wine stain) due to tumors within capillary bed.
-Hemangiomas of choroidal BV
-Diffuse leakage may lead to retinal detachment |
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Term
| retinopathy of prematurity |
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Definition
premature infants exposed to high concentration of oxygen form poorly developed retinal vasculature. Neovascular invasion of vitreous (vitreoretinal adhesion) are possible
Visual problems:
May precede hemorrhaging and retinal detachment. |
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Term
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Definition
day 1-21
rapid cell division and differentiation of primary germ layers |
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Term
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Definition
4-8 weeks
differentiation of all major internal and external body structures (vital organs first) |
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Term
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Definition
9 weeks to birth
growth stage, sexual differentiation, brain wave patterns show activity |
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Term
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Definition
single median eye or 2 fused at midline
Visual problems:
Major CNS problem, child will likely die. |
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Term
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Definition
greater than normal distance between orbits
Visual problems:
Forebrain is affected. |
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Term
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Definition
less than normal distance between orbits
Visual problems:
Midbrain affected |
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Term
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Definition
| absence of ocular tissue derived from optic cup |
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Term
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Definition
| small, underdeveloped globe and lens |
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Term
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Definition
| cornea and anterior segment enlarged, perhaps due to increased IOP |
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Term
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Definition
| normal sized globe, small cornea |
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Term
| persistent hyperplastic vitreous |
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Definition
failure of hyaloid arterial system to regress
White retrolental mass right in center of vitreous. |
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Term
| List the structures of the vitreous from strongest to weakest. |
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Definition
vitreous base
hyaloideocapsular ligament (of Weiger)
peripapillary
perimacular
retinal vessels |
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Term
| Location of vitreous base. |
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Definition
| 2mm over pars plana and 4mm over retina |
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Term
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Definition
| Fibers are embedded firmly in BM of non-pigmented ciliary epi and retinal Muller cells |
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Term
| Location of hyaloideocapsular ligament (of Weiger)? |
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Definition
| Between posterior lens capsule and vitreous. Annular attachment 1-2mm wide & 8-9mm in diameter. |
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Term
| Nature of the hyaloideocapsular ligament (of Weiger)? |
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Definition
| strength decreases with age |
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Term
| Location of peripapillary? |
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Definition
| edge of optic disc. attachment between vitreous and retinal tissue (ILM) |
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Term
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Definition
| can detach and form a visible Weiss ring |
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Term
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Definition
| annular ring around macula, 3-4mm |
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Term
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Definition
| Fine strands that extend throughout ILM to branch and surround large vessels. Accounts for bleeds when vitreous shrinks. |
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Term
| Location of anterior and posterior vitreous cortex. |
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Definition
Anterior cortex: adjacent to ciliary body, posterior chamber, lens.
Posterior cortex: in contact with retina
CORTEX IS ABSENT AT MACULA & DISC! |
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Term
| Location of intermediate zone of vitreous? |
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Definition
Between Cloquet's and the cortex.
Fibers run anteroposteriorly. |
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Term
| Composition of the intermediate zone of the vitreous? |
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Definition
| Fibers arise at region of vitreous base and insert into posterior cortex. |
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Term
| Location of vitreous Cloquet's canal? |
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Definition
Center of vitreous body
S-shaped
Terminates at the area of Martegiani |
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Term
| Composition of Cloquet's canal? |
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Definition
| Former site of hyaloid artery system. |
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Term
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Definition
| region of strongest attachment between the vitreous and the ora seratta |
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Term
| hyaloideocapsular ligament (of Weiger) |
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Definition
| annular attachment between the posterior surface of the lens and the anterior face of the vitreous |
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Term
| retrolental space (of Berger) |
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Definition
| potential space between the lens and vitreous |
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Term
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Definition
| prepapillary hole in the cortex; a funnel-shaped space at the optic nerve head that extends forward into the vitreous to become continuous with Cloquet's canal |
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Term
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Definition
| an indentation of the anterior surface of the vitreous where the lens sits |
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Term
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Definition
| branch of the ophthalmic artery, which is itself a branch of the internal carotid artery. It is contained within the optic stalk of the eye and extends from the optic disc through the vitreous humor to the lens. Usually fully regressed before birth, its purpose is to supply nutrients to the developing lens in the growing fetus. |
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Term
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Definition
--Synthesize HA, collagen, and ground substance.
--Phagocytic properties - often when [halocyte] cells are located posterior to the ora seratta.
--Anti-angiogenic |
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Term
The composition of the vitreous?
(List 5) |
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Definition
1. 98-99% water.
2. Collagen: concentration varies by region.
(Decreasing order: vit base-->cortex-->intermediate zone-->Cloquet's canal)
Appears to be continuous from anterior to posterior and may have components produced by Muller cells.
3. Hyaluronic Acid (HA):
Macromulecule located w/in collagen fibrillar network (maintains wide spacing between fibrils)
Highest [HA] in posterior cortex, and decreases toward anterior and central.
4. Fibroblasts: approx 10%
5. Halocytes |
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Term
| List 5 functions of the vitreous. |
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Definition
1. Storage area for metabolites (glucose, aa) and catabolites (lactic acid)
2. avenue for the movement of solutes through the eye
3. shock absorber, due to viscoelastic properties
4. transmits and refracts light, aiding in focusing rays on the retina
5. mechanically supports the retina |
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Term
| Age-related changes that occur in the vitreous? |
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Definition
Liquefaction!
@ age 40, 80% gel, 20% liquid
@ age 80, 50% gel, 50% liquid
--Note!! The liquid can enter the prepaillary hole, predisposing for vitreal and retinal detachment. Seepage of water between water and vitreous.
Fibrils aggregate!
-Less transparent vitreous
Vitreous base widens
--Increase tension
Vitreous shrinks and can detach from the retina
--Causing PVD
Note!!
Attachment at vitreal base gets stronger with age, adding increased tension/pull on peripheral vitreous. |
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