Slit Lamp Review Flashcards
1
Q
3 Uses for Diffuse Illumination
A
- View extent of corneal scar or neovascularization
- View corneal edema (looks gray and hazy)
- View lids and lashes for any abnormality
2
Q
How to set up Diffuse Illumination
A
- Select low mag
- Set illuminating arm to 45 degrees
- Set light intensity to low and open the beam to wide
- Illuminate the cornea from the side
3
Q
3 Uses for Sclerotic Scatter
A
- Observe corneal clouding
- Observe position and movement of a contact lens
- Observe if there is a disturbance of the normal transparency
(Nebula, macula, perforating scars, and pigmented areas will cause the light to scatter and appear white)
4
Q
How to set up Sclerotic Scatter
A
- Microscope should be aligned directly in front of the eye to be examined
- Use low power magnification first
- The angle between the microscope and illuminating arm should be 45 degrees or greater
- Light should be focused on the temporal side of the limbus
- A halo of light should be visible surrounding the cornea
5
Q
3 Uses for Tangential Illumination
A
- Observe floaters in the anterior chamber
- Use a blue filter to observe fleisher’s ring in keratoconus
- Review pathology of the anterior of the iris
6
Q
How to use the tangential illumination
A
- With the microscope directly in front of the eye, set the illuminating arm to 70 degrees
- Set slit to a moderate width
- Use low mag to to start
- Looking into the microscope, focus on the structure to be examined such as the surface of the iris
- For a more detailed study, refocus the microscope using the joy stick and increase the magnification
7
Q
3 uses for specular reflection
A
- Assess quality of the tear layer
- Observe endothelium
- Observe anterior corneal surface
8
Q
What is important to remember about specular reflection
A
The angle of incidence of the light will be equal to the angle of reflection
9
Q
How to set up specular reflection?
A
- Set the microscope to high mag
- Angle the light to 45-60 degrees to the microscope
- Adjust the slit to a medium width (parallel piped)
- Look into the microscope (tear film should be visible after blanks)
- Gradually change the angle the illuminating arm makes with the microscope until a bright area of the precorneal tear fluid is seen
10
Q
What are 3 direct illuminations
A
- Optic Section
- Parallel piped
- Conical Beam
11
Q
3 Uses for optic section:
A
- Discover any thickening and thinning of the cornea
- Examine crystalline lens
- Determine depth of a foreign body
12
Q
How to set up optic section
A
- Begin with oculars in front of the eye
- Set illuminating arm to 45 degrees
- Set to low mag (for now)
- Set slit to a narrow width (smaller then parralelpiped)
- Position the beam of the cornea ( a curved light and straight beam of light become visible )
- Narrow the slit and increase magnification to focus on a slice of the cornea
- Scan the cornea, once you get to the middle, swing the illuminating arm 90 degrees to the nasal side to view the other half of the cornea
13
Q
3 uses for parallel piped
A
- To determine CL fit (rigid lens with a blue filter and fluorescein)
- View anterior surface irregularities
- To detect epithelial staining (using fluorescein and blue filter)
14
Q
How to set up Parallelpiped
A
- Position the microscope in front of the eye
- Set illuminating arm to 45 degrees
- Use low mag first
- Set slit to medium width
- Med light intensity
- Increase mag for more detailed analysis
15
Q
2 Uses for conical beam
A
- Observe debris in the anterior chamber
2. Localize the light onto a small zone
