Lecture 3 SL Illumination Techniques Flashcards
Wide Beam \_\_\_\_ wide tall/short? Angle? intensity? mag?
5mm wide Tall beam 30-60' Medium intensity 10x mag
lids, lashes, conjunctiva, cornea, 10-16x mag
wide beam
3 types of direct illumination
parallelepiped
optic section
conical beam
3D examination of cornea, conj., lens, and iris
parallelepiped
Parallelepiped beam: direct/indirect/retroillumination/specular reflection? Size? \_\_ mm Angle? Intensity? Mag?
All; direct (most often), can do other though 2-4mm 20-60' medium --> high 10-16x
5 layers of the cornea?
- epithelium
- bowman’s membrane
- stroma (thickest)
- Descemet’s membrane
- endothelium
What is the only way we can see the endothelium?
specular reflection, parallelepiped
Used to determine the depth and location of a defect, most commonly used to see the layers of cornea or lens.
optic section
Optic Section set-up Width? (>\_\_mm) \_\_\_\_ beam (\_\_mm) Angle? Cornea and Lens Intensity? Mag?
Direction Illumination > 1mm width 8mm tall Cornea: 60' Lens: 20-30' medium to high intensity 16x mag
Is optical section 2D or 3D?
2D; epi –> stroma –> endo
DI: Optic Section
Front surface bright zone
tears
DI: Optic Section
dark gray lines after bright zone
epithelium
DI: Optic Section
bright thin line after dark gray line
Bowman’s membrane
DI: Optic Section
gray wider granular area
stroma
DI: Optic Section
last bright inner zone
epithelium
Used to estimate anterior chamber (angle) depth = Van Herick Technique
optic section
Van Herick Angle Estimation \_\_\_\_\_ section \_\_\_\_ side of the limbus Angle? Height? Intensity? Mag?
Optic section Corneal side of limbus. 60' tall medium to high 16x
Grade 4 Van Herick
< 1 : 1
Grade 3 Van Herick
0.25-0.5 : 1
Grade 2 Van Herick
0.25 : 1
Grade 1 Van Herick
< 0.25 : 1
Closed Van Herick
Close = no AC visible
Conical Beam Illumination? Required for what structure? Conic section dimensions? Illumination angle? Intensity? Mag?
Direct Illumination Anterior chamber 1mm wide x 2-4mm tall 30-45' angle maximum intensity 25x mag
Indirect Illumination Which type? Width? Height? Angle? Illumination? Mag?
Use parallelepiped 2-3mm width cornea: taller angle: 20-60' medium 10-16x mag
Which structures is indirect illumination used for?
cornea, lens and even retina
Which structures can specular reflection show?
corneal endothelium, anterior and posterior lens capsules
Specular reflection Which beam? How wide? How high? angle? magnification?
parallelepiped 2mm wide tall beam for cornea 20-45' angle 16-25x mag
What magnification do you use for sclerotic scatter?
none
How do you look for a corneal edema (loss of corneal transparency)?
sclerotic scatter
Sclerotic scatter set-up \_\_\_\_ parallelepiped beam Angle? Height? Mag?
WIDE parallelepiped beam
45-60’ angle
Tall
NO magnification
