Slit Lamp Examinations Flashcards
Diffuse Illumination
Illumination: Low
Illumination Angle: 30-45
Slit width: MAX
Slit Height: MAX
Magnification: 6.4x - 10x
Optic section
Illumination: Medium to High
Illumination Angle: 45
Slit width: <2 mm
Slit Height: MAX
Magnification: 16- 25x
Parallelpiped
Illumination: Low to Medium
Illumination Angle: 45
Slit width: 2-3mm
Slit Height: MAX
Magnification: 10 -25x
Conical beam
Illumination: High
Illumination Angle: 40-60
Slit width: <2mm
Slit Height: <2mm
Magnification: 16 -25x
Specular Reflection
Illumination: Low
Illumination Angle: 30 (30 Observation Arm)
Slit width: <2mm
Slit Height: MAX
Magnification: 16-40x
Tangential
Illumination:High
Illumination Angle: 75-90
Slit width: 2-3mm / same as parallelpiped
Slit Height: MAX
Magnification: 6.4x
Retro illumination from Iris
Illumination: Medium
Illumination Angle: 45
Slit width: <2mm
Slit Height: 4-5mm
Magnification: 16-40x
Retro illumination from Iris
Illumination: Medium
Illumination Angle: 45
Slit width: <2mm
Slit Height: 4-5mm
Magnification: 16-40x
Retroillumination from fundus
Illumination: Medium to High
Illumination Angle: 0-10
Slit width: <2mm
Slit Height: 4-5mm
Magnification: 10x
Retroillumination from fundus
Illumination: Low to Medium
Illumination Angle: 0-10
Slit width: <2mm
Slit Height: 4-5mm
Magnification: 10x
Sclerotic Scatter
Illumination: Medium - High
Illumination Angle: 45- 60
Slit width: <2mm
Slit Height: MAX
Magnification: 6.4x -10x
Van Herick Technique
Illumination: Medium - High
Illumination Angle: 60
Slit width: <2mm
Slit Height: MAX
Magnification: 6.4- 10x
What is the purpose of slit lamp biomicroscopy?
To diagnose eye conditions and evaluate the health of the anterior segment of the eye.
What is the purpose of the slit lamp biomicroscopy?
To diagnose eye conditions and evaluate the health of the anterior segment of the eye.
The slit lamp biomicroscope is consists of 3 systems. Name and their purpose
Illumination system - it sends the light into the patients eye.
Observation system - allows the observer to see the magnified structures.
Mechanical system - positioning and adjustment of patient and observer.
What is the magnification range provided by most slit lamps?
6x to 40x
What slit lamp biomicroscope has the light source located below the level of the slit?
Zeiss Slit lamp Biomicroscope
What is the principle is used in the illumination system of both Zeiss and Haag streit slit lamps
Kohler illumination principle
What is the purpose of the cobalt blue filter in slit lamp
Enhances the view of fluorescein dye in the tear film
What is the purpose of the green filter (Red free filter)
Enhances the view of blood vessels and hemmorhage
Normal endothelial shape
Hexagonal
Slit width for optic section illumination
<2mm
Slit height for retroillumination
4-5mm
Magnification for tangential illumination
6.4x
Illumination angle for specular reflection
30 (30 Observation Arm)
Purpose of indirect illumination
Provides a dark background allowing corneal opacities to be viewed with more contrast.
Purpose of sclerotic scatter
To highlight pathology by absorbing and scattering light through the cornea.
Normal TBUT
10-15 seconds
Purpose of Van Herick Texhnique
To evaluate the anterior chamber without gonioscopy.
What do you call when there’s a formation of small new blood vessels?
Neovascularization
What Illumination technique gives a good overall picture of the eye, but no fine details. It is the general survey of the eye.
Diffuse illumination
What are the structures you are observing in the parallel piped illumination?
Cornea, Iris, Lens
What illumination technique will you use if you want to examine the anterior chamber for flares, inflammatory cells, or floating particles?
Conical Beam
Illumination angle for diffuse illumination?
30-45
Slit width for parallel piped
2-3mm
Magnification range for optic section illumination
16-25x
Condition is typically examined using the conical beam technique?
Anterior uveitis
Illumination for specular reflection
Low
Normal shape of endothelial cells
Hexagonal
What is polymegethism
Variation in size of endothelial cells
Where are guttata typically found
Central cornea
What is the common indication of aging in the cornea
Hassall- Henle bodies
What is the illumination angle for tangential illumination
75-90
Slit height for retro illumination from the iris
4-5mm
Difference between anterior uveitis and closed angle attack regarding keratic precipitates
Present in anterior uveitis, absent in closed angle attack
Slit width is used for retroillumination from the fundus
<2mm
What optical principle does sclerotic scatter utilize?
Total Internal Reflection
What is the appearance of leucoma
White
Illumination angle for Van Herick Technique
60
Magnification range of sclerotic scatter
6.4-10x
Primary use of the parallel piped technique
General examination
Illumination level of conical beam
High
Optic section technique help visualize
A section of a structure without cutting it
