The document describes the slit lamp examination used in optometry. It discusses the history, principles, parts, magnification ranges, and illumination techniques of the slit lamp. The slit lamp uses a bright light source to illuminate the eye structures and allow examination at different magnifications. Various illumination techniques like diffuse, direct, and retro illumination can be used to examine different parts of the eye. The slit lamp allows for a detailed examination of the lids, conjunctiva, cornea, anterior chamber, iris, and lens.

1. Slit lamp examination
Bhaktiprada Sahoo
Optometrist & Ocularist

2. History
Allivar Gullstrand
 Noble prize -1911
 Slit lamp

3. Principle
 A narrow slit beam of
very bright light
produced by lamp.
This beam is focused
on to the eye which is
then viewed under
magnification with a
microscope

4. Parts
 Mechanical support
 Observation system
 Illumination system

5. Mechanical Support
 Forehead rest
 Chin rest
 Fixation target

6.  Power supply unit
 Locking control system

7. Observation System
 Binocular eye piece
 Observation tube
 Magnification changes

8. Illumination System
 Lamp housing unit
 Slit width and height
control
 Neutral density filter
 Cobalt blue light filter

9.  Red-free filter
 Field size control
 Diffuser
 prism

10. Magnification Range
 Low magnification -7x-10x
 Medium magnification – 20x-25x
 High magnification – 30x-40x

11. Low Magnification
 Lids
 Bulbar conjunctiva/ sclera
 Cornea / limbus
 Tear
 Anterior chamber

12. Medium Magnification
 Epithelium
 Stroma
 Endothelium
 Contact lens fit / lens condition

13. High Magnification
 Epitheium
1. Vacuoles
2. Microcysts
3. dystrophies
 Stroma
1. Straie
2. Folds
 Endothelium
1. Polymegathism
2. Guttata
3. Blebs
4. Dystrophies

15. Illumination Techniques
 Diffuse
 Direct
 Indirect
 Retro illumination
 Specular reflection
 Sclerotic scatter
 Tangential

16. Diffuse Illumination
 45° angle between light
and microscope
 Fully open slit
 Diffusing filter

17. Overall view
 Lids and lashes
 Conjunctiva
 Cornea
 Sclera
 Iris
 pupil

18. Direct Illumination
 Observation and illumination
system focused at same point
 Vary angle of illumination
 Low to high magnification
 Vary width and height of
light source

19. Optic section (Narrow, focused light)
 Indicates depth
 Localise
1. Nerve fibers
2. Blood vessels
3. Infiltrate
4. Cataracts
5. Anterior chamber angle

21. Parallelepiped (Wider, focused light)
 Wider field of view
 Illuminated block of
cornea
 More extensive
examination

22. Conical beam
 Inflammatory cells /flare in AC
 Darked room

23. Indirect Illumination
 Observation and
illumination systems are
not focused at same
point
 Vary angle of
illumination
 Vary beam width

24. Valuables for observing
 Epithelial erosions
 Epithelial Dystrophies

25. Retro Illumination
 Object is illuminated by
reflected light
 Moderately wide beam
 Medium to high
magnification
 Reflected light from iris or
fundus

26. Valuables for observing
 Vascularisation
 Limabal Injection
 Epithelial oedema
 Microcysts
 Vacuoles

27. Specular reflection
 Angle of incidence equal to angle of reflection
 Valuable for observing
 Endothelial cell
 Tear film lipid layer

28. Sclerotic Scatter
 Total internal reflection
of wide angle light source
 Valuable for observing
 Localized epithelial
Oedema
 Corneal Scar
 FB in Cornea

29. Tangential Illumination
 Large angle of 70 – 80 degree between illumination
and observation system.
 Valuable for observing
1. Iris nodules
2.General integrity of cornea and iris

30. Routine examination of the eye using
S/L Bio-microscope
 Lids
1. Redness, swelling,
 Puncta
1. Clear : functioning

31. Continuation
 Conjunctiva
1. Redness
2. Inflammation

32. Continuation
 Limbus
1. Redness
2. Neovascularisation
3. staining

33.  Cornea
1. Transparency
1. Tissues damage

34.  Tear
1. Quality
2. Lipid layer
3. debris

35.  Anterior chamber
1. Cells and flare
1. Persistent pupillary
membranes

36. Iris examination
 Inflammation
 Pigmentation
 Iridectomy
 coloboma

37. Crystalline lens examination
 Opacities
 Pigment on capsule
 Subluxation
 Iris attachments

38. Thank you