Clinical: Slit Lamp 1

Question 1

What is the formal name for a slit lamp?

Answer 1

Biomicroscope

Question 2

What is a slit lamp?

Answer 2

A high powered binocular microscope with a slit shaped illumination source

Question 3

What was/is the slit lamp designed to do?

Answer 3

View the different tissues of the eye for a general ocular health assessment

Question 4

What view do we get with the slit lamp?

Answer 4

Binocular, stereoscopic view

Question 5

Can you vary the magnification and illumination in the slit lamp?

Answer 5

Yes

Question 6

When is a slit lamp used?

Answer 6

-routine ocular exam
-problem specific exams (ie something in eye)
-contact lens eval
-baseline assessment before a procedure

Question 7

3 main parts/systems of the slit lamp:

Answer 7

-mechanical system (position control)
-illumination system (the slit lamp)
-magnification system (the biomicroscope)

Question 8

What is the mechanical system used for?

Answer 8

-position and adjustment
-joystick for movement
-base for other parts

Question 9

Parts of the mechanical system:

Answer 9

-motorized table
-pt positioning frame
-joystick

Question 10

Biomicroscope/magnification system:

Answer 10

-the viewing system
-binocular for depth perception
-large working distance to allow for manipulation

Question 11

How many lenses are in the optical system of the microscope?

Answer 11

2

Question 12

What does the objective lens consist of?

Answer 12

2 Plano-convex lenses providing a +22D power

Question 13

What does the ocular lens consist of?

Answer 13

+10D

Question 14

Why are there prisms in the microscope system of the slit lamp?

Answer 14

To overcome inverted image that a compound microscope produces

Question 15

What is the range of magnification on a slit lamp (typically)?

Answer 15

6x-40x

Question 16

What areas are 6x-10x best for?

Answer 16

Scanning large areas

Question 17

What is 16x (med mag) used for?

Answer 17

Evaluating details

Question 18

What is high mag (>16x) used for?

Answer 18

Magnifying small details

Question 19

What happens to field of view when magnification increase?

Answer 19

FOV decreases

Question 20

Why is it harder to maintain clarity with increased mag?

Answer 20

Due to decreased depth of focus

Question 21

How to focus the oculars on a slit lamp?

Answer 21

Turn all the way to the left (most plus) and slowly decrease the power until in focus
**do one eye at a time

Question 22

The illumination system in a slit lamp provides what type of light?

Answer 22

Bright, evenly illuminated, finely focused, and adjustable slit of light

Question 23

What does the slit shape of the light allow us to see?

Answer 23

Cross-sections of the ocular tissues

Question 24

What do the slit controls do?

Answer 24

Vary height, tilt, and width of light beam

Question 25

What does the reflecting mirror do?

Answer 25

Directs light from illumination source onto the eye

Question 26

What does the illumination arm do?

Answer 26

Change the position of reflecting mirror to alter the angle of the slit beam

Question 27

What other instruments can be used in tandem with a slit lamp?

Answer 27

-Goldman tonographer -gonioscopy lens -funduscopy lens -cameras -laser delivery systems

Question 28

What is included in “standard set-up” of the slit lamp?

Answer 28

-focus the eyepieces -adjust the PD -bright illumination and low mag -light source “in-click”

Question 29

Where should your hands be while controlling the slit lamp?

Answer 29

One on the joystick and the other on the slit beam

Question 30

Opaque tissues:

Answer 30

Eyelids, eyelashes, iris

Question 31

Transparent tissues:

Answer 31

-tears -conj -cornea -aqueous -lens -vitreous

Question 32

Translucent tissue:

Answer 32

Sclera

Question 33

Do you use the same technique to view all tissues?

Answer 33

No

Question 34

Which portions appear optically empty?

Answer 34

-Aqueous/anterior chamber -vitreous

Question 35

Which portions of the eye can you view each layer? Why?

Answer 35

-cornea and lens -do to discontinuity

Question 36

What surfaces of the eye are specular reflection seen?

Answer 36

SMOOTH surfaces Tear film, corneal endothelium, lens capsule

Question 37

What surfaces of the eye have diffuse reflection?

Answer 37

Irregular surfaces of the eye

Question 38

Why does light scatter?

Answer 38

Due to small particles suspended in a liquid or gas

Question 39

What light scattering effect makes most of the ocular tissues visible?

Answer 39

Tyndall effect

Question 40

What is the beam angle?

Answer 40

-The observation angle or illumination angle -angle between the slit beam light source and the microscope line of focus

Question 41

What is the beam angle range typically?

Answer 41

0-60 degrees

Question 42

How is the beam angle changed?

Answer 42

By moving the light source

Question 43

What is “click stop”

Answer 43

When the illumination arm and the microscope are in line with each other (you should feel it click into place)

Question 44

What another name for the coaxial position

Answer 44

Parfocality

Question 45

What is the coaxial position?

Answer 45

When the microscope and illumination are have a common center of rotation (they are aligned at the exact same spot)