Phsiologic Aging Changes Of The Cornea

Question 1

CCT at birth

Answer 1

Full adult thickness

Question 2

Horistonal diamater of cornea at birth

Answer 2

10mm, 90% of the adult value

Question 3

Axial length of cornea at birht

Answer 3

Just over 2/3 of adults

Question 4

At birth, the cornea occupies _____ of eye surface

Answer 4

25%

15% in adults

Question 5

Corneal aquires adult size at ____ years

Answer 5

3

Question 6

Sclera gorws until ______ years

Answer 6

10 to 12

Question 7

What does the sclera growing until 10 or 12 account for

Answer 7

Normal hyperopia among children.

Question 8

When do most eyes become emmetropic

Answer 8

6 to 8 years

Question 9

Ag related changes in the cornea and vision

Answer 9

Not detrimental to vision

Question 10

When will vision be affected with corneal aging changes

Answer 10

If change is central cornea and affects the transparency of the tissue

Question 11

Where do most age related corneal changes happen

Answer 11

At the periphery

Question 12

Corneal sensitivity and aging

Answer 12

Decreases

Question 13

Light scatter and corneal aging

Answer 13

Increases

Question 14

Corneal curvature and aging

Answer 14

Flattening of the cornea (vertically) causing ATR astigmatism

Question 15

Bowmans membrane and corneal aging

Answer 15

Stippling

Question 16

Descemet’s membrane and corneal aging

Answer 16

Thickening

Question 17

The most common aging change in the cornea

Answer 17

Corneal arcus

Question 18

Annular yellow-white deposit located within the peripheral stroma

Answer 18

Corneal arcus

Question 19

What is corneal arcus separated from the limbus by

Answer 19

A zone of clear cornea

Question 20

What are the deposits in corneal arcus

Answer 20

Cholesterol or cholesterol esters

Question 21

What does corneal arcus result from

Answer 21

Age or elevated blood cholesterol levels

Question 22

Arcus extending over time

Answer 22

Can extend anteriorly over time to bowmans layer or into the central cornea

Question 23

Clinical significance in those with corneal arcus

Answer 23

Non in elderly persons, but in those under age 40, hyperlipidemia should be suspected

Question 24

What race is corneal arcus more common and pronounced

Answer 24

Blacks

Question 25

What percent of population has corneal arcus by age 50

Answer 25

50%

Question 26

What percent of population has corneal arcus by age 80

Answer 26

100%

Question 27

Is corneal arcus unilateral or bilateral

Answer 27

Bilateral

Question 28

What layer of the cornea can corneal arcus effect

Answer 28

Bowmans

Question 29

What should you consider in someone with corneal arcus

Answer 29

Cardiovascular risk factors

Question 30

Corneal epithelium and aging

Answer 30

Alterations to cellular transmembrane receptors (integrins) - these form bridges from cell to cell and from cell to ECM - link cytoskeleton to ECM - fibronectin - change results in reduction in the adhesion molecules necessary for intercellular junction construction

Question 31

Los of intracellular junctions in the corneal epithelium

Answer 31

Causes a breakdown in the barrier function of hte corneal epithelium

Question 32

Decreased keratocyte density in the corneal epithelium

Answer 32

Can adversely affect wound healing and colllagen fibril degradation produces spaces that can disrupt transparency and create opacities

Question 33

Iron deposits in epithelial cell cytoplasm, mroe concentrated in basal cells, produce a horizaotnal pigmented line

Answer 33

Hudson-stahli line

Question 34

Where is a Hudson-Stahli line evident

Answer 34

At the level of the lower lid margin

Question 35

When does Hudson-Stahli line fade

Answer 35

Usually present between 50 and 70, fades after that

Question 36

What should you consider with someone who has Hudson-Stahli lines

Answer 36

Hydrochloroquine use

Question 37

Degeneration of bowmans layer

Answer 37

Lima girdle of Vogt

Question 38

Where is the limbs girls of vogt found and what color is it

Answer 38

This yellowish white opacity is located at the 3 and 9 o clock positions

Question 39

Limbal girdle of Vogt type I

Answer 39

A clear interval separating the opacity from the limbus In type II this is not seen

Question 40

The area around the Lima girdle of Vogt

Answer 40

May include degeneration of the anterior stroma, calcium deposits, and hypertrophy of the overlying epithelium

Question 41

Changes in descemets membtane with age

Answer 41

Increases in thickness | Hassall-henle boidies increase in the periphery

Question 42

Small round peripheral endothelial indentations produced by thickening of descemets membrnae

Answer 42

Hassall-henle bodies

Question 43

Appear as corneal guttata (peripheral_

Answer 43

Hassall-Hanle bodies

Question 44

What must you rule out in Hassan-Henle bodies

Answer 44

Fuch's

Question 45

What can Hassal-Henle bodies cause

Answer 45

Atypical arcus

Question 46

When does endothelial cell density decrease

Answer 46

With cell loss

Question 47

What is a normal endothelial cell density

Answer 47

4000 cells/mm2

Question 48

Polymegathism

Answer 48

Greater than normal variation in size of the corneal endothelial cells

Question 49

Pleomorphism

Answer 49

Increases variability in size and shape

Question 50

Pigment deposits on the posterior cornea with a vertical orientation

Answer 50

Krukenberg's spindle

Question 51

What do you need to be careful with the a Krukenberg's spindle

Answer 51

High IOP

Question 52

A decrease in corneal sensitivity corresponds to a loss of corneal ____with age

Answer 52

Nerves

Question 53

Changes in refractive components and in eye size must be well-balanced during childhood growth to allow for

Answer 53

Emmetropization

Question 54

When does refractive error result

Answer 54

Eye is too short or too long or if the cornea is too flat or too steep

Question 55

What is refractive error typically due to

Answer 55

Eye length

Question 56

____ may be a factor when emmetropization does not occur

Answer 56

Scleral tissue

Question 57

When does myopia usually develop

Answer 57

8-14 years

Question 58

What is myopia most often cause by

Answer 58

The lengthening of posterior eye, containing the vitreous

Question 59

Scleral connective tissue components and visual environment

Answer 59

Can change in response to changes in the visual environment

Question 60

Poor image quality on the retina and scleral tissue components

Answer 60

Poor image quality on the retina can elicit a signal to scleral tissue components to strengthen or weaken in an attempt to move the retina to the best location for a clear image

Question 61

Sunlight and myopia

Answer 61

- altered light cycles cause eye growth and myopia in animal studies - a reduced risk of myopia with increased outdoor activity - reduction in myopia with latitudes near equator - either do to light intensity or greater object distances

Question 62

What does scleral remodeling cause

Answer 62

Axial lengthening that occurs in myopia; existing scleral tissue is weakened and thins. In progressive myopia, collagen is degraded, the production of newcollagen is reduced, and matric proteoglycans are lost

Question 63

Changes of the sclera during myopia development

Answer 63

Changes int he ECM but an additional piece of the puzzle may be the role played by scleral fibroblasts; if stimulated to become myofibrils. They can produce biochemical signals leading to changes in collagen production and degradation of tissue

Question 64

The progression of myopia caused by axial elongation in a highly myopic eye often causes scleral thinning, particularly at the posterior pole where the collagen fibril diamtere and the bundle size are reduced. As the sclera thins, the tissue can bulge outward causing this

Answer 64

Scleral ectasa

Question 65

Yellow sclera with age

Answer 65

Fatty deposits

Question 66

Scleral collagen and elastic fibers in aging sclera

Answer 66

Degenerate

Question 67

Fibers of the lamina cribrosa and age

Answer 67

Become stiffer and less resilient -may make the nerve fibers passing through the openings more susceptible to injury, contributing to an increased susceptibility to glaucomatous damage.