Eye Flashcards
What includes the Corneoscleral coat of eye
Sclera + cornea
What are the three layers of the eye
Corneoscleral coat
Vascular coat
Retina
What includes the vascular coat of eye
UVEA
Choroid + stroma of ciliary body and iris
What is included in the retinal layer
Retina and epithelium of ciliary body and iris
What are the three chambers of the eye
Anterior chamber
Posterior chamber
Vitreous chamber
Eye development starts at 22 days with what structure
Optic sulci
An invagination occurs that forms the optic cup… What do the layers of the optic cup make
Inner layer- neural retinal layer
Outer layer- retinal pigmented epithelium
Why is the choroid fissure in the eye important
It allows hyaloid vessels to reach the inner chamber of the eye
What does the proximal portion of the hyaloid artery become
Central artery and vein of the retina
What is the key regulatory gene for eye development
PAX6
What does PAX 6 do?
Initiates the formation of a single eye field that is later separated Into two by SHH
What is a coloboma
Cleft in the iris
What are congenital cataracts
Clouding of lens during intrauterine life
Can be caused by rubella
What is microphthalmia
When the eye is too small
Often from CMV or toxoplasmosis
Anophthalmia
Absence of an eye
Congenital aphakia
Absence of the lens
Usually caused by defect in pax 6
Cyclopia
Fusion of the eyes
What are factors that can affect midline structures and cause synophthalmia
Alcohol
Mutations in SHH
Defects in cholesterol metabolism
Aniridia ?
Absence of the iris
Mutations of PAX 6
What is WAGR syndrome
Wilm’s tumor
Aniridia
Genitourinary abnormalities
Retardation (mental)
What is the first layer of the cornea and what is it made of
Corneal epithelium
5 layers of stratified squamous epithelium
What is conjunctivilization of the cornea
Vascularization, appearance of goblet cells, and irregular/unstable epithelium
What is your anterior BM that doesn’t regenerate in your cornea
Bowman’s membrane
What is the third layer of the cornea and what is it made of
Corneal stroma
Collagen fibrils
What is the fourth layer of the cornea that can regenerate
Descemet’s membrane
What is the fifth layer of the cornea that provides for metabolic exchange
Corneal endothelium
What do the tendons of the extra ocular muscles insert onto
Sclera
The Corneoscleral limbus is an abrupt transition from where to where
The cornea to the sclera
The canal of Schlemm drains the aqueous humor from where
Anterior chamber
The most anterior part of the vascular coat (or uvea) is _______
The iris
What kind of epithelium does the ciliary body and processes have
Ciliary epithelium
What are the three functions of the ciliary epithelium
Secretion of aqueous humor
Participate in blood-aqueous barrier
Secretion and anchoring of zonular fibers that form suspensory ligament of lens
What kind of connections holds the cells together of the ciliary epithelium and creates ciliary channels
Desmosomes
Gap junctions
What is the route of circulation of aqueous humor
Ciliary body > between iris and lens > anterior chamber of eye > lateral to cornea and iris >trabecular meshwork > canal of Schlemm
What are the two types of glaucoma
Open angle
Closed angle
What occurs in open angle glaucoma
Trabeculae meshwork drains the aqueous humor but canal of Schlemm is blocked
What occurs in closed angle glaucoma
Nothing drains because of inflammation
How do carbonic anhydrase inhibitors help glaucoma
They inhibit aqueous humor formation (carbonic anhydrase isoenzyme CA2
What are the two layers of the choroid
Choriocapillary layer
Bruch’s membrane
What are the 4 types of cells of the retina
Photoreceptors
Conducting neurons
Association neurons
Supporting cells
The retinal pigmented epithelium helps form the blood-retina barrier but what does that do
Isolates retinal cells from blood borne substances
What type of image do rods provide
Gray tones
What type of image do cones provide
Red, green, and blue tones
What is the fovea
Small shallow depression at the posterior pole of the eye
Foveola?
Central region of the fovea that is almost entirely cones
Macula lutea?
Area surrounding fovea
Why is the macula lutea yellow
It has xanthophyll
What is the optic disc
Blind spot where optic nerve exits
How does a retinal detachment occur
A potential space exists between two layers of optic cup
The neural retina can pull away from the retinal pigment epithelium
What is dry AMD
Degenerative lesions of the macula lutea (thickening of Bruch’s membrane, depigmentation of retinal pigmented epithelium, destruction of capillaries)
What is wet AMD
Complication of dry AMD where new blood vessels begin to appear that can leak
What are the fibers that suspend the lens in the eye
Zonular fibers
What is the lens capsule made of
Type 4 collagen
Proteoglycans
What are the three layers of the lens
Lens capsule
Subscapular epithelium
Lens fibers
The lens is normally transparent but it is filled with what protein
Crystallins
How does excess glucose cause cataracts
Sorbitol interacts with crystallins making them less opaque
What do hyalocytes do in the vitreous body
Synthesize collagen fibrils and glycosaminoglycans
