Illumination Techniques

Question 1

What is diffuse illumination good for

Answer 1

1. Contact lens evaluations
2. general overview of lids/lashes
   illumination intensity is low
   tall beam
   mag 6-10

Question 2

what is wide beam illumination good for

Answer 2

view of lids/lashes, conj and good “overview” of cornea
Tall beam
Medium intensity for illumination
mag at 10

Question 3

What is direct illumination palalelpiped good for

Answer 3

examination of cornea, conj, lens and iris
Tall beam
2-4 mm width
angle is 20-60
medium to high illumination intensity
mag is 10-16 
x

Question 4

direct illumination parallelpiped is used with ___ illumination, ____ reflection, and retro illumination. It is the most effective illumination at detecting tissue abnormalities. When focused sharply it provides a 3D illumination of the cornea

Answer 4

indirect; specular

Question 5

What is optic section used for

Answer 5

determining the depth and location of a defect. Most commonly used for cornea or lens
Narrow beam
Tall beam
medium to high II
Mag 16 X
2D!

Question 6

What are the landmarks of the optic section

Answer 6

1. pre corneal tear film
2. eptihelium
3. BM
4. Stroma
5. DM

Question 7

what is optic section useful for

Answer 7

1. detecting changes in the cornea..thickening/thinning
2. detecting the location of lenticular opacities such as cataracts
3. abrasions/ulcer/foregn bodies/opactities

Question 8

Normal and young crystalline lens will illuminate as a ____optic section

Answer 8

white; yellows with age

Question 9

When determining van herick grade angle which grade are you worried about

Answer 9

1 and 2

Question 10

Grade 1 is ____than a quarter the width of the corneal optic section. grade 4 has the width of the chamber equal to corneal optic section

Answer 10

less

Question 11

what kind of grading would you get if you are far too centrally

Answer 11

angle estimation will be artificially greater

Question 12

what is conical beam useful for

Answer 12

examining the AC
conic section: 1 mm wide x 2-4 mm tall
ill angle: 30-45
illuminity intensity: Max
mag: 25
examiner dark adapts for 30 s

Question 13

What are cells/flare indicative of

Answer 13

iritis/uveitis

Question 14

floating cells move up near the warmer _____ and down near the cooler _____corneal surface

Answer 14

iris; posterior

Question 15

flare =

Answer 15

floating protein

Question 16

cells=

Answer 16

wbc/white dots

Question 17

what is the purpose of sclerotic scatter

Answer 17

to look for corneal edema (loss of corneal transparency)
Wide parallelpiped beam
tall beam
NO mag!
angle: 45-60
pupil observed with naked eye!

Question 18

Sclerotic scatter is the only technique that utilizes _____ of cornea

Answer 18

TIR

Question 19

Wide beam is mostly for _____. Parallelpiped is for ____ and depth. Optic section is mostly for ____

Answer 19

surface; surface; depth

Question 20

Angles are important in viewing the cornea and lens because it allows for viewing depth without the distraction from ____ from upper layers. Also allows for better estimation of depth and better detection/perception of _____. Angles allow for direct/indirect/retro simultaneously!

Answer 20

reflection; texture

Question 21

what is indirect illumination good for

Answer 21

cornea, lens and even the retina
parallelpiped beam
medium intensity
10-16 mag
Depends on where YOU look

Question 22

What is the purpose of indirect illumination

Answer 22

to produce a softer illumination to give better detection and definition.
2nd most common impt technique!

Question 23

Indirect is widely used for observation of cornea and corneal irregularities such as ____ _____

Answer 23

corneal infiltrates

Question 24

Specular reflection is useful for:

Answer 24

looking at corneal endothelium, anterior and posterior lens capsules
Parallelpiped beam
mag 16-25

Question 25

specular reflection deals with ___ law!

Answer 25

snells; the mosaic is seen in only ONE ocular!

Question 26

Retroillumination deals with the cornea and lens; mainly ____ tissues

Answer 26

transparent

Question 27

Transillumination deals with the ____; and opaque tissues

Answer 27

iris

Question 28

What is the purpose of retroillumination

Answer 28

to place the tissue you need to study against a bright background

Question 29

where is your light focused at if your doing retro of the cornea

Answer 29

on the iris

Question 30

where is your light focused at if your doing retro of the iris or lens

Answer 30

in pupil

Question 31

we usually detect ____ while using retro illumination

Answer 31

cataracts