9 Aging And The Cornea

Question 1

T/F at birth the cornea has the full adult thickness

Answer 1

True

Question 2

In newborns the axial length of the eye is ____ of an adults

Answer 2

2/3

Question 3

When does the cornea reach adult size

Answer 3

Age 3

Question 4

The sclera grows to what age

Answer 4

10-12

Question 5

When do most eyes become emmetropic

Answer 5

6-8

Question 6

Aging changes to the cornea impede vision

Answer 6

No, only if the central cornea is affected or the transparency is affected

Question 7

As we age what happens to corneal sensitivity

Answer 7

It decreases

Question 8

As we age what happens to light scatter

Answer 8

It increases

Question 9

Does teh cornea get flatter or steeper as we age

Answer 9

Flatter

Question 10

What happens to Bowmans membrane

Answer 10

It stipples

Question 11

What happens to descemets membrane

Answer 11

Thickens

Question 12

What is the most common aging change in the cornea

Answer 12

Arcus

Question 13

What is arcus

Answer 13

An annular yellow-white deposit in the peripheral stroma

Question 14

What makes the deposits in arcus

Answer 14

Cholesterol and cholesterol esters

Question 15

What can cause arcus

Answer 15

Age or elevated blood cholesterol levels

Question 16

Should we be concerned when we see arcus

Answer 16

NO, not unless it is in a person less than 40 y.o.

Question 17

by age 50 what percent of the population has arcus

Answer 17

50%

Question 18

By age 80 what percent of the population has arcus

Answer 18

100%

Question 19

Is arcus unilateral or bilateral?

Answer 19

Bilateral

Question 20

What changes happen in the corneal epithelium

Answer 20

Alterations in the transmembrane receptors resulting in a reduction in the adhesion molecules

Question 21

What does loss of intracellular junctions in the corneal epithelium cause

Answer 21

Breakdown of the epithelium function

Question 22

Decreased keratocyteis in the epithelium affects what

Answer 22

Wound healing

Question 23

Collagen fibril degradation in the epithelium has what affect on the cornea

Answer 23

Opacities

Question 24

What is the Hudson-Stahli line?

Answer 24

Iron deposits in the epithelium, created a horizontal pigmented line. Evident at the lower lid margin

Question 25

What is the Kimble girdle of Vogt

Answer 25

Degeneration of Bowmans layer. Located at 3 and 9 o clock. Evident as a yellowish opacity

Question 26

What are Hassall-Henle bodies?

Answer 26

Small round endothelial indentations caused by thickening of descemets membrane. Appear as corneal guttata

Question 27

What happens to endothelial cell density

Answer 27

Decreases with cell loss

Question 28

What changes occur in endothelium

Answer 28

Decrease in cell density Polymegalism (large cells) Pleomorphism (increased variable size and shape)

Question 29

What are Krukenbergs spindle

Answer 29

Pigment deposits in posterior cornea with vertical orientation

Question 30

What happens to corenal sensitivity with age?

Answer 30

Decreases due to loss of corenal nerves

Question 31

What must occur for emmetropizaton happen

Answer 31

Changes in refractive components and the eye size must be well balanced during growth to allow emmetropization

Question 32

What is the usual cause of refractive error

Answer 32

Eye length

Question 33

When does myopia occur

Answer 33

8-14 years

Question 34

What is the main cause of myopia

Answer 34

Lengthening of posterior eye

Question 35

There is a reduced risk of myopia with (increased/decreased) outdoor activity?

Answer 35

Increased

Question 36

What does scleral remodeling cause

Answer 36

Axial lengthening that occurs in myopia, the scleral tissue is weakened and thins

Question 37

What is scleral ectasia

Answer 37

Tissue bulge on the sclera caused by thinning

Question 38

What refractive error has a higher risk of ectasia?

Answer 38

Myopia

Question 39

As fatty deposits accumulate what happens to the sclera

Answer 39

Yellows

Question 40

What happens to proteoglycans in the sclera

Answer 40

Decrease

Question 41

What happens to the lamina cribrosa

Answer 41

Becomes stiffer and less resilient making eye more susceptible to glaucomatous damage