Slit lamp

Question 1

what is click stop

aka parafocal alignment/coupling

Answer 1

light and microscope converge on the same area of interest

Question 2

what is out of click stop

Answer 2

light is immediately adjacent to the area of interest

Question 3

what do the slit lamps basic componenets to

Answer 3

1. evaluate the health of the ant and post segment of the eye
2. assess contact lens fits

Question 4

moving the joystick towards the eye enables you to focus on more _____ structures

Answer 4

posterior

Question 5

to view flat surfaces how do yo move the joystick? how about to view convex structures?

Answer 5

flat: move joystick across in a straight line
convex: move joystick parallel to the convex surface

Question 6

what is direct focal?

what are teh 3 types

Answer 6

-microscope and light beam focused on the same area
parallelepiped
optic section
conical beam

Question 7

what is diffuse illumination?
what mag
what is it used to screen
what is the angle of illumination

Answer 7

• wide beam of light illuminating a large area
• low mag
• use: general screening of upper and lower lids, lashes, puncta, conjunctiva, no fine detail
• 45 degrees

Question 8

what kind of beam does parallelepied use? angle? what can you view?

Answer 8

moderately side beam
angle 45
gives a broader view of conj, cornea, iris

Question 9

what is optic section used to evaluate? what kind of detail?

Answer 9

1. evaluate layers of cornea
2. asses thinning/thickening of cornea
3. asses ant chamber using VH
4. evauluate lens
5. fine detail

Question 10

what is the principle behind conical beam?

Answer 10

tyndall phenomenon: visibility of beam of light caused by floating particles (cells) in the ant chamber

Question 11

what kind of mag does conical beam use?
what should the examiner be wen using this?
where is light directed?
what kind of beam?

Answer 11

• high mag, high ill, and reduced room ill
• examiner should be dark adapted
• light directed through the pupil
• beam should be widest and shortest

Question 12

what does conical beam asses

Answer 12

anterior chamber cells-WBC, RBC
flare-proteins
-presence of cells and flare is a sign of ocular inflammation: commonly in the unveal tract
-cells and flare should be graded by severity

Question 13

in indirect focal illumination, how is the microscope focused?

• what do you look at?
• what is it used to observe?

Answer 13

microscope focused next to the light

• by looking next to the light
• by moving the light source out of “click stop” position
• used to observe fine corneal vascularization
• useful for iris pathology

Question 14

how is the light reflected in retroillumination?

what are the 2 types and how are they different

Answer 14

light is reflected from deeper (post) structure to view more ant structure

1. direct retro: observed structure is in the pathway of reflected light
2. indirect: microscope is focused adjacent to the reflected beam of light (simliar to out of click stop)

Question 15

in sclerotic scatter what beam is used?

what do you observe

Answer 15

• focus on broad, bright beam at the temporal limbus
• microscope focused on the cornea
• observe the halo around the cornea at the nasal limbus
• look at the cornea from outside of the slit lamp to view corneal edema for the best view

Question 16

what is specular reflection used to examine?
type of mag?
what kind of beam?
how to position the light source?

Answer 16

• to examine the corneal endothelium
• high mag
• side parallelepiped
• position the light source so that the corneal light reflection is captured through one of the oculars

Question 17

what are the 2 types of filters used? what are they used for?

Answer 17

1. cobalt blue
   - goldmann tonometry
   - tear film assessment
   - corneal staining
2. red free
   - differentiate crescents
   - cws
   - choroidal nevus

Question 18

what is the range of mag used

Answer 18

6-40x

Question 19

what can high mag be very useful to assess

Answer 19

corneal scar/ulcers
ant chamber infl
guttata
iris neo
pigment dispersion on lens/corneal endothelium 
pseudoexfoliation

Question 20

if what you’re seeing doesn’t look right, what are the 3 questions to ask yourself

Answer 20

1. is the pd adjusted for you
2. are each of the eyepieces adjusted appropriately for you
3. is the lamp out of parafocal alighment

Question 21

if you cant see anything from the lsit lamp, what questions to ask yourself

Answer 21

1. is the width so narrow it is closed?
2. are you btwn aperature settings?
3. is the microscope so far from the pt that is way out of focus?
4. are you btwn mag settings?
5. is the bulb burned out?
6. is the slit lamp plugged in and turned on? is it wired through the stand?