Lecture 3 SL Illumination Techniques

Question 1

Wide Beam
\_\_\_\_ wide
tall/short?
Angle?
intensity?
mag?

Answer 1

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

Question 2

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

Answer 2

wide beam

Question 3

3 types of direct illumination

Answer 3

parallelepiped
optic section
conical beam

Question 4

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

Answer 4

parallelepiped

Question 5

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

Answer 5

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

Question 6

5 layers of the cornea?

Answer 6

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

Question 7

What is the only way we can see the endothelium?

Answer 7

specular reflection, parallelepiped

Question 8

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

Answer 8

optic section

Question 9

Optic Section set-up
Width? (>\_\_mm)
\_\_\_\_ beam (\_\_mm)
Angle? Cornea and Lens
Intensity?
Mag?

Answer 9

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

Question 10

Is optical section 2D or 3D?

Answer 10

2D; epi –> stroma –> endo

Question 11

DI: Optic Section

Front surface bright zone

Answer 11

tears

Question 12

DI: Optic Section

dark gray lines after bright zone

Answer 12

epithelium

Question 13

DI: Optic Section

bright thin line after dark gray line

Answer 13

Bowman’s membrane

Question 14

DI: Optic Section

gray wider granular area

Answer 14

stroma

Question 15

DI: Optic Section

last bright inner zone

Answer 15

epithelium

Question 16

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

Answer 16

optic section

Question 17

Van Herick Angle Estimation
\_\_\_\_\_ section
\_\_\_\_ side of the limbus
Angle?
Height?
Intensity?
Mag?

Answer 17

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

Question 18

Grade 4 Van Herick

Answer 18

< 1 : 1

Question 19

Grade 3 Van Herick

Answer 19

0.25-0.5 : 1

Question 20

Grade 2 Van Herick

Answer 20

0.25 : 1

Question 21

Grade 1 Van Herick

Answer 21

< 0.25 : 1

Question 22

Closed Van Herick

Answer 22

Close = no AC visible

Question 23

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

Answer 23

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

Question 24

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

Answer 24

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

Question 25

Which structures is indirect illumination used for?

Answer 25

cornea, lens and even retina

Question 26

Which structures can specular reflection show?

Answer 26

corneal endothelium, anterior and posterior lens capsules

Question 27

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

Answer 27

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

Question 28

What magnification do you use for sclerotic scatter?

Answer 28

none

Question 29

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

Answer 29

sclerotic scatter

Question 30

Sclerotic scatter set-up
\_\_\_\_ parallelepiped beam
Angle?
Height?
Mag?

Answer 30

WIDE parallelepiped beam
45-60’ angle
Tall
NO magnification