1. Slit Lamp Training
Tim Buckley
Product Manager

2. Basics Definition and Applications
The purpose of a slit lamp is the biomicroscopy of the patient‘s eye under different lighting conditions. The slit lamp projects a bright and homogenously illuminated slit onto the eye which is variable in length, width, angle and light intensity.
Fields of Application
The primary field of application is the anterior eye segment (cornea, anterior chamber, lens, anterior vitreous).
Using additional optics enables the user to also examine the posterior eye segment as well as the anterior chamber angle.

3. Basics Design Principles
components: microscope, slit projector, instrument base
carrier arms for microscope and slit projector can be swiveled around a common axis
swivelling axis is located in the focal plane of microscope and slit projector

4. Basics Design Principles - Biomicroscope
Zeiss slit lamps: Galilei type microscope
common front objective
parallel beam path
3 or 5 magnification steps
other manufacturers also offer Greenough type microscopes
two separate, tilted beam paths
only 2 magnification steps
very few accessories

5. Basics Design Principles - Slit Projector
purpose: to project a slit image focused on the patient‘s eye
the slit image is variable in length, width and angle
light source: usually halogen (high color temperature)
filters: blue, green (redfree), diffusor, heat absorbing filter

6. Basics Design Principles - Instrument Base
functional coupling of carrier arms of microscope and slit projector
slit projector and stereo microscope can independantly be swiveled around a common axis
Axis is located below patient’s eye
both slit image and observation are in focus in the axial plane
three-dimensional positioning by joystick

7. Basic Functions of the Slit Lamp Slit Width
narrow slit circle shaped, if
fully opened
slit width is adjusted continuously

8. Basic Functions of the Slit Lamp Slit Length
short slit long slit
slit length is adjusted in steps and
continuously

9. Basic Functions of the Slit Lamp Slit Rotation
vertical slit horizontal slit vertical slit
slit rotation can be adjusted continuously by ±90°

10. Basic Functions of the Slit Lamp Slit Decentration
decentered slit
slit can be decentered continuously by ±4°

11. Basic Functions of the Slit Lamp Tilting Prism
angle of incidence 0° angle of incidence 20°
tilting prism can be tilted by 0° to 20° continuously
positions 0°, 5°, 10°, 15°, 20° indexed

12. Forms of direct Illumination
Types of Illumination
Forms of direct Illumination

13. Types of Illumination Direct Diffuse Illumination
Principle
illumination of the eye with a broad, unfocused light beam
usage of diffusor
microscope positioned at 0°
magnification 5x x
Applications
Overview
general assessment of anterior eye, eye lids
assessment of contact lenses

14. Types of Illumination Direct Diffuse Illumination
IOL
iris supported anterior chamber lens in
diffuse illumination
Bildquelle: Universitäts-Augenklinik Jena

15. Types of Illumination Direct Focal Illumination - Optic Section
Principle
Illumination and observation are focused in the same plane
slit width ca. 0,1 to 0,3mm
Applications
mainly findings in the cornea and lens
opacities, scars, vessels
good perception of the depth of findings

16. Types of Illumination Direct Focal Illumination - Optic Section
Cataract
anterior cortical opacities, nucleosclerosis
and posterior opacities
Bildquelle:

17. Types of Illumination Direct Focal Illumination - Optic Disc
Principle
Illumination and observation are focused in the same plane
slit width ca. 2 to 4mm
Applications
mainly findings in the cornea and lens
opacities, scars, vessels
good perception of shape and size of findings

18. Types of Illumination Direct Focal Illumination - Optic Disc
Cyst on Pupillary Edge
Cyst on pupillary edge stems from usage
of too strong miotica
Bildquelle:

19. Types of Illumination Direct Focal Illumination - Conical Beam
Principle
assessment of particles floating in the anterior chamber by illuminating with a light beam
Tyndall‘s phenomenon
pinpoint illumination 0,3 - 0,5mm
Applications
assessment of particles in aqueaous humor
inflammation cells, pigmented cells, metabolic waste

20. Types of Illumination Direct Focal Illumination - Conical Beam
cells in anterior chamber
cells in anterior chamber as a sign of
uveitis
Bildquelle:

21. Types of Illumination Tangential Illumination
Principle
a narrow light beam is projected almost parallel along the structure to be observed
elevated structures are visible by shadowing
Applications
elevated abnormities or changes in the iris
tumors, cysts

22. Types of Illumination Tangential Illumination
Iris
Iris in tangential illumination

23. α

24. Types of Illumination Specular Illumination0° α
Types of Illumination Specular Illumination
Principle
angle of incidence = angle of reflection
observation and illumination have same angle to perpendicular axis
slit width < 4mm
Applications
assessment of surfaces
assessment of tear film
endothelial cell layer

25. Types of Illumination Specular Illumination0° α
Types of Illumination Specular Illumination
endothelial cells
endothelial cell layer magnified ca. 192x
Bildquelle: Carl Zeiss Meditec

26. Forms of indirect Illumination
Types of Illumination
Forms of indirect Illumination

27. Types of Illumination Indirect focal Illumination
Principle
illumination by stray light
slit is slightly decentered so that stray light is created in direct neighbourhood of the finding
slit width ca. 2 to 4mm
Applications
mainly corneal lesions and scars

28. Types of Illumination Indirect focal Illumination
no example

29. Types of Illumination Direct Retro-Illumination from the Iris
Principle
Illumination of the finding with indirect light rflected from the iris
observation with light background
medium slit width, ca. 2 to 4mm
Applications
Infiltrations, small scars, corneal vessels, micro cysts, vacuoles
with this illumination findings are made visible with high contrast

30. Types of Illumination Direct Retro-Illumination from the Iris
Keratitis Superficialis Punctata
finding after moderate cauterization by
acid, defects of epithelium and conjunctiva
have been stained with bengal rose
Bildquelle:

31. Types of Illumination Indirect Retro-Illumination from the Iris
Principle
Illumination of the finding with indirect light reflected from the iris
observation with dark background
medium slit width, ca. 2 to 4mm
Applications
Infiltrations, small scars, corneal vessels, micro cysts, vacuoles

32. Types of Illumination Indirect Retro-Illumination from the Iris
Keratitis Punctata, contact lens wearer
multiple erosions of the central cornea due
to inappropriate contact lens fitting
Bildquelle:

33. Types of Illumination Retro-Illumination from the Lens
Principle
Illumination of the finding with indirect light reflected from the lens
observation with light background
medium slit width, ca. 2 to 4mm
Applications
corneal defects, foreign bodies, scars
(type of illumination not frequently used)

34. Types of Illumination Retro-Illumination from the Lens
no example

35. Types of Illumination Retro-Illumination from the Fundus
Principle
Illumination of the finding with indirect light reflected from the fundus
observation with red/yellowish background
dilated pupil
Applications
abnormities in the anterior vitreous, lens, anterior chamber, cornea
findings are visible like silhouettes

36. Types of Illumination Retro-Illumination from the Fundus
Aniridia
missing iris and zonular cataract made
visible by retro-ilumination
Bildquelle:

37. Types of Illumination Iris-Transillumination
Principle
transillumination of the iris by indirect light reflected from the fundus
half dilated pupil (3 to 4mm)
Illumination and observation at ca. 0°
Applications
Visualization of defects of the pigment layer of the iris

38. Types of Illumination Iris-Transillumination
Albinism
Iris-Transillumination shows the light
transmission of the iris
Bildquelle:

39. Types of Illumination Sclerotic Scatters
Principle
Illumination of the limbus region with a broad light beam at an angle of 45° - 60°, decentered slit
total reflection of the incoming light at inner corneal boundaries (endothelium and epithelium)
Applications
scars, foreign bodies, corneal defects
irregularities in the cornea cause straylight

40. Types of Illumination Sclerotic Scatters
corneal scar
corneal scarring after infection
Bildquelle:

41. Fundus Observation and Gonioscopy

42. Fundus Observation and Gonioscopy Contact Glasses
additional tool for fundus observation with the slit lamp
mostly direct: erect and non mirrored image of the fundus
required: dilated pupil, use of gliding liquid
Fundus Image
Microscope
Bildquelle:

43. Fundus Observation and Gonioscopy Lenses
additional tool for fundus observation with the slit lamp
mostly indirect: upside-down and mirrored image of the fundus (convex optics)
non contact
required: dilated pupil
microscope
Inverted fundus image
Bildquelle:

44. Fundus Observation and Gonioscopy Gonioscopy
Three mirror contact glass
Goldmann contact glass
central lens: posterior pole
73° mirror: equator
67° mirror: ora serrata
59° mirror: anterior chamber angle
central lens
Bildquelle:

45. Fundus Observation and Gonioscopy Gonioscopy
Three mirror contact glass
Goldmann contact glass
central lens: posterior pole
73° mirror: equator
67° mirror: ora serrata
59° mirror: anterior chamber angle
73° mirror
Bildquelle:

46. Fundus Observation and Gonioscopy Gonioscopy
Three mirror contact glass
Goldmann contact glass
central lens: posterior pole
73° mirror: equator
67° mirror: ora serrata
59° mirror: anterior chamber angle
67° mirror
Bildquelle:

47. Fundus Observation and Gonioscopy Gonioscopy
Three mirror contact glass
Goldmann contact glass
central lens: posterior pole
73° mirror: equator
67° mirror: ora serrata
59° mirror: anterior chamber angle
59° mirror
Bildquelle:

48. Fundus Observation and Gonioscopy Example: Fundus
retinal scar
microscope
Bildquelle: UAK Jena / Carl Zeiss

49. Fundus Observation and Gonioscopy Example: Anterior Chamber Angle
blood in chamber angle
vessels in chamber angle

50. Examination using Fluorescein

51. Examination using Fluorescein
Principle
Fluorescein is inserted into the conjunctival sac and fills, for example, intracellular spaces
dye is excited with blue light (λ nm)
contrast reducing straylight is blocked with barrier filter (yellow filter λ > 530 nm)
Applications
corneal lesions / defects
contact lens fitting

52. Applanation Tonometry

53. Applanation Tonometry
Principle (according to Prof. Goldmann)
diameter of the applanated area: 3,06 mm
counteracting forces of corneal rigidity and capillary attraction cancel each other out
applanated force (AF) equals the intraocular pressure (IOP)
Applications
measurement of intraocular pressure
IOP AF

54. Applanation Tonometry
measuring figures
a: applanation force
too low
b: correct setting
c: applanation force
too high

55. Length and Angle Measurement

56. Längen- und Winkelmessung
Length and Angle Measurement
Diameter of cornea and pupil
height of conjunctival folds
anterior chamber depth
toric contact lenses

57. Redfree Examination

58. Redfree Examination
Objects with high portion of red (e.g. fundus, vessels)
contrast enhancement through green filter