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Flashcards in Eyes Deck (65)
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1

What are the three layers of the eyeball?

External - sclera and cornea
Intermediate - anterior (iris and ciliary body) and posterior (choroid)
Internal - retina

2

What is the anterior chamber of the eye?

Between the cornea and iris
Filled with aqueous humor

3

What is the posterior chamber of the eye?

Between the iris, zonule fibers and lens
Filled with aqueous humor

4

What is the vitreous chamber of the eye?

between lens and retina
Filled with vitreous humor

5

What does the aqueous humor do?

Nourishes the cornea and lens

6

What does the vitreous humor do?

Exerts pressure to maintain the shape of the eye

7

Define the limbus

The junction between the sclera and the cornea

8

Define canthi refer

Junction between the upper and lower eyelids

9

Where does the iris and posterior structures of the eye (with the exception of the lens) originate from?

Neuro-ectodermal layers

10

Where does the lens and all the structures anterior to the iris originate from?

Embyonic ectodermal layer

11

What causes a coloboma?

Failure of the neuro-ectodermal tissue to wrap around the lens placode and fuse in a double layer inferiorly

12

What causes infantile glaucoma or buphthalmos?

Failure of the development of the iridocorneal angel and/or the Canal of Schlemm

13

Where does the nasolacrimal duct open into?

Inferior meatus of the nose

14

What secretes aqueous humor? Where is is located?

Ciliary body behind the iris

15

What is the circulation of aqueous humor?

drains through the pupil, then into the iridocorneal angle where it is reabsorbed into the Canal of Schlemm

16

What causes of aqueous humor drainage fails?

Glaucoma
Increased intraocular pressure
Can cause retinal damage and blindness

17

Define ptosis. What can cause it?

Drooping of the eyelid.
CN III nerve palsy, sympathetic dysfunction (Horner's), neuromuscular disease (Myasthenia Gravis)

18

Define lid retraction

Patient will have wide eyed starring appearance. Superior sclera is visible on opening of the eyes fully.

19

Define ectropion

Turning outward (sagging) of the eye margin.
It is often associated with aging.
There is a constant flow of tears down the medial side of the face.

20

Define entropion

Turning inward of the lid margin.
This can cause abrasion of the cornea.

21

Define a stye

AKA hordeolum
Red, swollen and tender
Pus discharge

22

Define blepharitis

Margin is red and irritated
Covered with scales

23

Define a chalazion

Cyst like
No acute signs of inflammation
Due to inspissated secretions of the mibomian glands

24

Define Xanthelasma

Discrete, waxy, yellowish deposit on the medial aspect of the lid

25

What are the signs of allergic reaction of the eye?

Pale, boggy swelling of all four eyelids

26

Define Chemosis

Swelling
Fluid in the episcleral space

27

Define pinguecula

Whitish-yellow, triangular, nodular growth on the nasal portion of the bulbar conjuctiva adjacent to the corneal-scleral junction (limbus)
Does NOT invade the cornea

28

Define pterygium

Similar in location to a pinguecula, but more vascular.
Begins at the medial canthus and extends beyond the corneal-scleral junction

29

Define arcus senilis

White ring in the cornea
Normal >40yo
< 40yo is a sign of hypercholesterolemia

30

Define Kayser-Fleisher ring

Greenish-yellow rings in the cornea
Seen in Wilson's disease - copper deposition in Descemet's membrane of the peripheral cornea