Lecture 3 SL Illumination Techniques Flashcards Preview

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Flashcards in Lecture 3 SL Illumination Techniques Deck (30)
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1

Wide Beam
____ wide
tall/short?
Angle?
intensity?
mag?

5mm wide
Tall beam
30-60'
Medium intensity
10x mag

2

lids, lashes, conjunctiva, cornea, 10-16x mag

wide beam

3

3 types of direct illumination

parallelepiped
optic section
conical beam

4

3D examination of cornea, conj., lens, and iris

parallelepiped

5

Parallelepiped beam:
direct/indirect/retroillumination/specular reflection?
Size? __ mm
Angle?
Intensity?
Mag?

All; direct (most often), can do other though
2-4mm
20-60'
medium --> high
10-16x

6

5 layers of the cornea?

1. epithelium
2. bowman's membrane
3. stroma (thickest)
4. Descemet's membrane
5. endothelium

7

What is the only way we can see the endothelium?

specular reflection, parallelepiped

8

Used to determine the depth and location of a defect, most commonly used to see the layers of cornea or lens.

optic section

9

Optic Section set-up
Width? (>__mm)
____ beam (__mm)
Angle? Cornea and Lens
Intensity?
Mag?

Direction Illumination
> 1mm width
8mm tall
Cornea: 60'
Lens: 20-30'
medium to high intensity
16x mag

10

Is optical section 2D or 3D?

2D; epi --> stroma --> endo

11

DI: Optic Section
Front surface bright zone

tears

12

DI: Optic Section
dark gray lines after bright zone

epithelium

13

DI: Optic Section
bright thin line after dark gray line

Bowman's membrane

14

DI: Optic Section
gray wider granular area

stroma

15

DI: Optic Section
last bright inner zone

epithelium

16

Used to estimate anterior chamber (angle) depth = Van Herick Technique

optic section

17

Van Herick Angle Estimation
_____ section
____ side of the limbus
Angle?
Height?
Intensity?
Mag?

Optic section
Corneal side of limbus.
60'
tall
medium to high
16x

18

Grade 4 Van Herick

< 1 : 1

19

Grade 3 Van Herick

0.25-0.5 : 1

20

Grade 2 Van Herick

0.25 : 1

21

Grade 1 Van Herick

< 0.25 : 1

22

Closed Van Herick

Close = no AC visible

23

Conical Beam
Illumination?
Required for what structure?
Conic section dimensions?
Illumination angle?
Intensity?
Mag?

Direct Illumination
Anterior chamber
1mm wide x 2-4mm tall
30-45' angle
maximum intensity
25x mag

24

Indirect Illumination
Which type?
Width?
Height?
Angle?
Illumination?
Mag?

Use parallelepiped
2-3mm width
cornea: taller
angle: 20-60'
medium
10-16x mag

25

Which structures is indirect illumination used for?

cornea, lens and even retina

26

Which structures can specular reflection show?

corneal endothelium, anterior and posterior lens capsules

27

Specular reflection
Which beam?
How wide?
How high?
angle?
magnification?

parallelepiped
2mm wide
tall beam for cornea
20-45' angle
16-25x mag

28

What magnification do you use for sclerotic scatter?

none

29

How do you look for a corneal edema (loss of corneal transparency)?

sclerotic scatter

30

Sclerotic scatter set-up
____ parallelepiped beam
Angle?
Height?
Mag?

WIDE parallelepiped beam
45-60' angle
Tall
NO magnification