Optics Lecture 6 Flashcards Preview

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Flashcards in Optics Lecture 6 Deck (30):
1

Which modality to use for intraorbital features

MRI

2

Which modality to use to image cell morpholog

Confocal microscopy

3

Which modality to use to image the epithelial layer

Ultrasound biomicroscopy

4

Which modality to use for quick pachymetry

Ultrasound

5

Which modality to use to image the vitreous when corneal opacity is present

Ultrasound biomicroscopy

6

Which modality to use to image the ciliary body

Ultrasound biomicroscopy

7

Which modality to use to measure axial length with the BEST PRECISION

Optical low coherence interferometry

8

Is the a-scan quantitative or qualitative

Quantitative

9

What are the 3 axial data found from a-scan

Axial length
AC depth
Corneal thickness

10

Is the A-scan precise in measuring?

No, it is hard to be accurate

11

Is the b-scan quantitative or qualitative?

Qualitative

12

Acoustical modalities - what kind of waves?

Ultrasound

13

Acoustical modalities - how is the penetration

Good

14

Acoustical modalities - does it require immersion coupling

Yes - often a contact technique

15

Optical modalities - what kind of waves

Visible or infrared radiation

16

Optical modalities - how is the penetration?

Poor

17

Optical modalities - does it require immersion coupling?

No - no contact

18

Provides imaging of entire visual path

MRI

19

Does sound move faster or slower in air than water

Slower in air

20

Formula to use when comparing an ultrasound sys with a high frequency ultrasound sys

Multiply the MHz by axial resolution and divide by the other that only gave 1 number

21

Better resolution comes from what kind of wavelength

Shorter

22

A or B scan to get numerical values

A scan

23

A or B scan to get morphology/shapes

B scan

24

Is the ultrasound reliable for measuring peripheral thickness?

No

25

What modality measures things behind the iris and can penetrate through tissue that is normally covered by optical opacities

Ultrasound biomicroscopy

26

Can you see behind the iris when using an optical modality?

No

27

How thick is average corneal thickness

55-60 microns

28

In lasik, how thick is the flap on average

120 microns

29

Why is optical low-coherence reflectometry better than a-scan

More precise, accurate measurements and better resolution

30

Average axial length

22-24 mm