Axial Length

Question 1

What is the normal axial length

Answer 1

22-24mm

Question 2

In combination with the corneal curvature, it determined the refractive state of the eye

Answer 2

Axial length

Question 3

What is axial length important for

Answer 3

Calculating the power for the IOL along with keratometry

Question 4

With an axial length of 20mm, we may suspect

Answer 4

HYPEROPE

Question 5

With an axial length of 26mm, we may suspect

Answer 5

Myopia

Question 6

Long eye

Answer 6

Myopic

Question 7

Short eye

Answer 7

Hyperopic

Question 8

What is the axial length in myopes

Answer 8

Longer than 24mm

Question 9

What is the axial length in hyperopes

Answer 9

Shorter than 24mm

Question 10

What does each mm of axial mismatch correspond to

Answer 10

2.3D to 3.4D of a refractive deviation

Question 11

Separation between the posteiror corners and the anterior lens

Answer 11

Anteiror chamber depth

Question 12

Normal AC depth

Answer 12

3.0-3.4 mm

Question 13

What happens to the AC depth with age

Answer 13

Decreases to 2.0mm

Question 14

What happens to axial length with age

Answer 14

Nothing

Question 15

AC depth and cataract

Answer 15

Cataracts decrease AC depth

Question 16

How soon should you treat a closed angle

Answer 16

ASAP, within 2 days

Question 17

Anterior chamber volume

Answer 17

220 and 171 +- 36 microliters

About 0.007 fluid ounces

Question 18

Anterior angle chamber (iridocorneal angle) normal range

Answer 18

30 degrees

Question 19

Anterior chamber angle less than 30

Answer 19

Narrow

Question 20

Anterior chamber angle more than 30

Answer 20

Wide open

Question 21

The angle formed by the posteiror cornea at the root of the iris

Answer 21

Anteiror chamber angle

Question 22

What is associated with small anteiror chamber depth

Answer 22

Cataracts and glaucoma

Question 23

The measurement of pupil diameter

Answer 23

Pupilometry

Question 24

Clinical importance for pupilometry

Answer 24

Selection of optical zone in laser refractive surgery

Question 25

Clinical importance of centroid shift

Answer 25

IOL andLaser ablation centration

Question 26

Best way to measure pupils

Answer 26

Infrared

Question 27

What size pupil should you look at when picking optical zone size

Answer 27

Scotopic

Question 28

Centroid shift

Answer 28

When the pupil dilates, it doesn't necessarily stay in the center

Question 29

Cyclotorsion

Answer 29

When pt lay done, there eyes rotate about 10 degrees. You don't want to be off by more than 3 degrees

Question 30

Measuring the thickness of the cornea

Answer 30

Corneal pachymetry

Question 31

Why is it not easy measuring the corneal thickness

Answer 31

It is not the same thickness throughout

Question 32

What is the most reliable pachymetry

Answer 32

Cornea pachymetry map

Question 33

The thickness of the cornea at the pupil center

Answer 33

CCT

Question 34

Where is the cornea thickest

Answer 34

Superonasal

Question 35

Is corneal thickness symmetric

Answer 35

No

Question 36

What are the two numbers we report for corneal pachymetry

Answer 36

CCT and MinCT

Question 37

Corneal enantiomorphic symmetry

Answer 37

Inferotemporal cornea should be the thinnest

Question 38

Corneal thickness in the morning

Answer 38

Thicker

Question 39

Measuring corneal pachymetry between two different eyes

Answer 39

Will not give you the same numbers

Question 40

Where is the corneal thinnest

Answer 40

Apex (minCT), slightly inferotemporal

Question 41

What is CCT defined at

Answer 41

The pupil center

Question 42

Average CCT

Answer 42

520-580

Question 43

CCT and age

Answer 43

No change

Question 44

When is CCT thicker

Answer 44

Upon waking

Question 45

Between two different devices, what kind of difference will you see in measuring CCT

Answer 45

20 microns difference

Question 46

Why is corneal thickness important

Answer 46

It can mask an accurate reading of eye pressure

Question 47

When is IOP underestimated

Answer 47

Thinner CCT

Question 48

When is IOP overestimated

Answer 48

Thicker CCT

Question 49

What kind of cornea will you see in corneal dystrophy

Answer 49

Thick

Question 50

Ocular health indicators of thick cornea

Answer 50

- endothelial cell damage, Fuchs dystrophy - corneal edema, bullus keratopathy, posteiror polymorphous dystrophy - herpes keratitis, DM, hyperglycemia

Question 51

Principle of operation of scheimpflug image pachymetry

Answer 51

High resolution, high depth of field imaging

Question 52

What did scheimpflug do

Answer 52

Tilt the lens