Optics Lecture 7 Flashcards Preview

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Flashcards in Optics Lecture 7 Deck (24):
1

Average axial length

22-24mm

2

With an axial length of 20mm, we might suspect

Hyperopia

3

With an axial length of 26 mm, we might suspect

Myopia

4

Each mm of axial length mismatch corresponds to how much of a refractive deviation

2.3-3.4D

5

Normal range of anterior chamber depth in adults

3-3.4mm

6

What happens to the ACD with age; what is its "final" depth

Decreases; 2mm

7

What 2 conditions affect ACD

Catarct and glaucoma

8

Volume in AC

Between 220 and 171 +/- 36 microL (.0007 fluid ounces)

9

Normal angle in adults

30 degrees

10

What pathologies are associated with smaller anterior chamber angle

Cataract and glaucoma

11

Which will give more detail of the cornea, pentacam or OCT and angle

OCT

12

Measurement of pupil diameter

Pupilometry

13

Which pupil measurement is used in determination of optical zone

Scotopic

14

Why is it not easy to measure the cornea

Because it is not the same thickness everywhere (thinnest in middle, then temp, then nasal)

15

Where is CCT located

At the pupil center (black dot in center of dashed circle)

16

Where is the minCT located

The most orange/red area, slightly inferotemporal

17

When looking at corneas, should they look the same or opposite?

Opposite (corneal asymmetry)

18

Average range of CCT

520-580 microns

19

When is CCT thickest

Upon waking

20

With a thinner CCT, what is important to remember when checkin IOP

Underestimated

21

With a thicker CCT, what is important to remember when checkin IOP

Overestimated

22

Indications of a thick cornea

- Endothelial cell damage, Fuchs dystrophy

23

What is the problem with scheimpflug imaging pachymetry

High resolution requires small depth of field

24

What is the solution for the scheimpflug imaging pachymetry

Tilt the lens