PC - Slitlamp Biomicroscopy 1 - Week 3 Flashcards
Is slit-lamp biomicroscopy examination done routinely as part of an eye exam, or not?
It is a must for all routine eye exams for the anterior segment.
What other instruments allow the examination of the structures as a slit-lamp would?
None, no other instrument provides the same scope for the anterior segment.
Would a slit-lamp be needed for fitting contact lenses, or is there another instrument better suited to this?
It is a must for contact lens fitting.
Name 6 uses for a slit-lamp.
Contact lens fitting Fundus exam Tonometry (goldmann) Gonioscopy Anterior segment imaging FB removal
Name 4 uses for the red-free filter on a slit-lamp.
- Enhances contrast when looking at blood vessels, haemorrhages, microaneurysms, and SVP
- Corneal or iris neovascularisation
- Retinal nerve fibre layer
- Layer of pigmentation
Name 4 uses for using the cobalt-blue filter.
For viewing fluorescein.
- Damage to epithelial corneal/conjunctival cells
- Tear break-up time (TBUT)
- Seidel test
- Viewing the Keyser-Fleischer ring in keratoconus
Name 10 slit-lamp techniques
-Diffuse illumination
-Optic section
-Parallelepiped
-Specular reflection
-Indirect illumination
-Retroillumination
-Sclerotic scatter
-Vital staining (fluorescein)
-Van Herrick
Small spot
Describe direct illumination.
Name the beam illumination, angle, width, and height.
Any technique where the slit-lamp and viewing system are focussed coincidentally. Angle - 30-60 Width - 1mm Height - 2mm Broader for general screening Illumination max
What 7 structures are viewed using direct illumination.
Eyelids, lashes, cornea, lens, conjunctiva, iris, and AC
Describe diffuse illumination.
Name the beam illumination, angle, width, and height.
Uses a wide, low intensity beam, or a ground glass filter is used to diffuse the focussed light. Angle ~60 Width max Height max Illumination low-med
What 7 structures are viewed using diffuse illumination.
Corneal deposits CL deposits CL fit External eyelid/lash abnormalities Conjunctiva Cornea
Can diffuse illumination be used to discern depth?
No.
Describe optic section.
Name the beam illumination, angle, width, and height.
Illumination source is oblique, not always 60. Structures behind are in darkness. Angle ~60 Width thinnest Height max Illumination medium
Can optic section be used to discern depth?
Yes, that is its main use for lesions
Which technique gives maximum contrast?
Optic section
Describe parallelepiped.
Name the beam illumination, angle, width, and height.
Narrow vertical slit used to illuminate a block of the cornea.
Is like an optic section, but wider, for a general scan, before switching to optic section if something is found.
Angle ~60
Width 2-3mm
Height max
Illumination medium
What 6 structures are viewed using parallelepiped.
Cornea/lens epithelium Cornea/lens endothelium Corneal integrity Depth and extent of corneal abrasion CL fit and surface Tear flim
What is the most common technique to assess the cornea?
Parallelepiped
Describe small spot.
Name the beam illumination, angle, width, and height.
Like direct illumination with a small spot, producing a cylindrical beam.
Name 2 uses for the small spot technique.
Examination of the anterior chamber
Detection of floating debris and anterior chamber cells/flares
Describe indirect illumination.
Name the beam illumination, angle, width, and height.
Light is focussed just to the side of the object to be observed. Angle ~60 Beam 1mm Height max Illumination medium
Name 3 uses for indirect illumination.
Detecting faint irregularities
Deeper areas of tissue
Foreign bodies
Describe retroillumination.
Name the beam illumination, angle, width, and height.
Two types
Direct and indirect (just next to the reflected light)
Light is focussed at the edge of the pupil.
Angle 60
Width 1mm
Height max
Illumination medium