The Eye

Question 1

What are the three layers of the eye?

Answer 1

1) Sclera
2) Choroid
3) Retina

Question 2

What is the sclera?

Answer 2

outer white layer

maintains shape

Muscles attached control movement

Question 3

What is the choroid?

Answer 3

Middle layer

Blood vessels

Question 4

What is the retina?

Answer 4

innermost layer

Rods
Cones

Bipolar cells

Question 5

What is the cornea?

Answer 5

Clear circular area in the sclera where light enters the eye

Question 6

What is the pupil?

Answer 6

Circular opening in front of the choroid

Question 7

What is the iris?

Answer 7

Colored smooth muscle surrounding the pupil which adjusts the opening according to the brightness of the light

Question 8

What is the lens?

Answer 8

Located behind the pupil, between the anterior and posterior chambers

In a constant state of adjustment as it becomes thinner or thicker to accomodate the detailed input it receives

Question 9

What is aqueous humor?

Answer 9

transparent, watery fluid similar to plasma but containg low protein concentrations

Fill both anterior and the posterior chambers of the eye

Formed by the ciliary body, enters the posterior chamber, bathes the lens, and circulates through the pupil to gain access to the anterior chamber

Question 10

What is vitreous humor?

Answer 10

Located in the space between the lens and retina - aka vitreous chamber

Question 11

What are the rods and cones?

Answer 11

synapse with bipolar cells which thensynapse with ganglion cells whose axons form the optic nerve

Question 12

What do rods do?

Answer 12

night vision

Question 13

What do cones do?

Answer 13

Color blindness

Question 14

What is the orbit?

Answer 14

compartment that is closed medially, laterally, and posteriorly

Question 15

What is proptosis?

Answer 15

disease of the orbit that increases the orbital contents and displaces the eye forward

Question 16

What are examples of proptosis diseases?

Answer 16

Graves disease

Enlargement of the lacrimal gland from inflammatio or neoplasm

Question 17

What is the eyelid?

Answer 17

Composed of skin externally and mucosa (conjunctiva) on teh surface apposed to the eye

Generates critical components of the tear film

Question 18

What is the palpebral conjunctiva?

Answer 18

Lines the interior of the eyelid

Question 19

What is the bulbar conjunctiva?

Answer 19

Covers the surface of the eye

Question 20

What is the limbus?

Answer 20

Intersection between the clear and the cornea

Question 21

What does bacterial and viral conjunctivitis cause?

Answer 21

Redness and itching

Heals without sequelae

Question 22

What does Chlamydia trachomatis cause?

Answer 22

Significant conjunctival scarring

Question 23

What is a pinguecula?

Answer 23

Yellowish patch or bump on the conjunctiva near the cornea

Submucosal elevations on the conjunctiva from actinic damage (UV)

Question 24

What is Pterygium?

Answer 24

Triangular shaped growth of fleshy tissue on the white of the eye that eventually extends over the cornea

Change in the normal tissue that results in a deposit of protein, fat, or calcium

Can develop from a pinguecula

Question 25

What does the corneal stroma lack?

Answer 25

Blood vessels and lymphatics It is immunoprivileged

Question 26

What are keratitis and ulcers caused by?

Answer 26

Bacterial, fungal, and viral (especially herpes simplex and herpes zoster) and protozoan (acanthamoeba) infections

Question 27

What does corneal neovascularization cause?

Answer 27

Risk of corneal graft rejection

Question 28

What is myopia?

Answer 28

EYe is too long for its refractive power Light is focused in front

Question 29

What is hyperopia?

Answer 29

Eye is too short and light is focused behind

Question 30

What are the types of corneal degeneration?

Answer 30

Non-hereditary unilateral and bilateral

Question 31

What are corneal dystrophies?

Answer 31

Bilateral and hereditary

Question 32

What is keratoconus?

Answer 32

Progressive thinning and ectasia of the cornea without evidence of inflammation or vascularization leading to conical cornea which is bilateral

Question 33

What is keratoconus associated with?

Answer 33

Down syndrome Marfan syndrome Atopic disorders

Question 34

What is Fuchs Endothelial Dystrophy?

Answer 34

Loss of endothelial cells causing edema and thickening within cornea Common indication for corneal transplantation

Question 35

What are the clinical manifestations of Fuchs endothelial dystrophy?

Answer 35

Stroma edema | Bulbous keratopathy

Question 36

What is psudophakic bulbous keratopathy?

Answer 36

Endothelial cells decrease following cataract surgery

Question 37

What is the anterior chamber?

Answer 37

Bound anteriogly by the cornea, laterally by the trabecular meshwork and posteriorly by the iris

Question 38

What are cataracts?

Answer 38

Occur in anterior segment Lenticular opacities that may be congenital or acquired

Question 39

What are the causes of cataracts?

Answer 39

Systemic disease = galactose is, diabetes Mellitus Drugs = corticosteroids Radiation Trauma Age-related = opacification of the lens nucleus (nuclear sclerosis)

Question 40

What is glaucoma?

Answer 40

Collection of diseases characterized by distinctive changes in the visual field and in the cup of the optic nerve Associated with elevated intraocular pressure from aqueous humor not draining properly

Question 41

How does aqueous humor drain?

Answer 41

``` Posterior chamber (ciliary body production —> Pupil —> Anterior chamber —> trabecular meshwork —> Schlemm’s canal ```

Question 42

What is open-angle glaucoma?

Answer 42

Drainage angle formed by the cornea and iris remains open, but the trabecular meshwork is partially blocked

Question 43

What is angle-closure glaucoma?

Answer 43

The iris bulges forward to narrow or block the drainage angle formed by the cornea and iris

Question 44

What is the primary cause of open-angle glaucoma?

Answer 44

Genetics

Question 45

What are the secondary causes of open-angle glaucoma?

Answer 45

Ocular vascular malformations | Trauma

Question 46

What is the primary cause of angle-closure glaucoma?

Answer 46

Hyperopia

Question 47

What are the secondary causes of angle-closure glaucoma?

Answer 47

Retinal ischemia | Tumors

Question 48

What is ophthalmitis?

Answer 48

Intraocular inflammation causes by vessels in the ciliary body and iris becoming leaky and allowing cells and exudate to accumulate in the anterior chamber

Question 49

What is anterior synechiae?

Answer 49

Inflammatory exudate in the anterior chamber causing adhesions between the iris and the trabecular meshwork or cornea

Question 50

What is posterior synechiae?

Answer 50

Inflammatory exudate in the anterior chamber causing adhesions between the iris and anterior surface of the lens

Question 51

What is endophthalmitis?

Answer 51

Inflammation within the vitreous humor

Question 52

What is panophthalmitis?

Answer 52

Inflammation within the eye that involves the retina, choroid, and sclera and extends into the orbit

Question 53

What is caused by anterior synechiae?

Answer 53

increased intraocular pressure and optic nerve damage

Question 54

What is caused by posterior synechiae?

Answer 54

Anterior subscapular cataract