The document summarizes the slit lamp biomicroscope, an instrument used to examine the eye. It has three main components: the mechanical support system, observation system, and illumination system. The illumination system provides a thin slit of light that can be focused on different areas of the eye. The slit lamp allows high-quality stereoscopic viewing of the eye and provides various types of illumination for examining different ocular structures. It can also be used to perform procedures like tonometry and gonioscopy.

1. Presented by
Dr. Md.Ashfakur Rahaman
D.O Student, RpMC

2. SLIT LAMP
Slit lamp biomicroscope is a
relatively low powered compound
microscope with a adjustable bright
light source, specially designed to
view the different optically
transparent layers of the eye.

4. The instrument is known as
slit lamp because the
illumination is arranged in a
pattern that a narrow
vertical slit of light is
projected onto the eye.

7. Criteria of a modern slit lamp
 Binocular stereoscopic view.
 Wide range of magnification from
cornea to retina.
 Illumination of variable shape and
intensities.
 Quantitative measurement by its
auxiliary devices like IOP, endothelial
cell count, pupil size, corneal thickness,
anterior chamber depth etc.
 Photography of every part is possible.

8. Types

11. Parts of a slit lamp
Mechanical support system
Observation system
Illumination system

12. Mechanical System
Joy stick arrangement
Up and down movement
arrangement
Patient support arrangement
Fixation target
Mechanical coupling

14. Observation system
 It is a compound microscope which is
composed of two convex lenses-
The objective lens (+22D)
The eye piece lens (+10D)
 To provide good stereopsis the tubes are
converged at an angle of 10-15 degree.

17. Illumination system
 The Gullstand’s illumination system is
designed to provide a bright, illuminated,
finely focused adjustable slit of light at the
eye.
 Components of illumination system:
1. Light source
2. Condenser lens system
3. Slit and other diaphragms
4. Filter
5. Projection lens
6. Reflecting mirror or prism

19. Methods of illumination
1. Direct illumination:
a) Diffuse illumination
b)Slit /direct focal
c) Specular reflection
2. Indirect illumination:
a) Retro illumination
- fundus retroillumination
- iris retroillumination
b) Sclerotic scatter

20. Direct diffuse illumination
 Full height
 Broad beam
 Directed obliquely
 Lower illumination level
 Filters can be used
Used for overview of anterior segment of eye.

22. Direct focal/ slit illumination :
 Full height & medium width
 Medium-bright beam
 Obliquely directed
 An optical cross-section (slit) is created
by narrowing to a very thin beam < 1 mm
wide

23. Uses:
Cornea in detail
Anterior chamber
 Crystalline lens
Anterior part of vitreous
Grading cell and flare in anterior
chamber

24. Specular reflection
 The angle of incidence is equal to the
angle of reflection.
 The light reflected from the anterior or
posterior corneal surface
 Method is monocular
 Shows abnormalities of the endothelium
such as reduced cell density and guttata.

26. Indirect illumination:
 Slit beam focused on a position just
beside the areas to be examined
 Beam width moderate
 Illumination low, medium or high
 Angle 30-40°
Uses:
Corneal infiltrates
Micro-cysts
Vacuoles
Epithelial cells

27. Retroillumination:
 Light reflected on iris or fundus
 Microscope focused on cornea
 For better visualization of:
Epithelial cysts
Keratic precipitates
Small blood vessels

28. Scleral Scatter
 Light incident on the limbus
 The microscope focused centrally
 Light transmitted to cornea by total internal
reflection
 Useful to detect subtle stromal haze and
cellular or lipid infiltration

30. Filters
White filter
Overview of ocular surface tissues
Examining intraocular structures
Cobalt blue filter
Coneal abrasion
Applanation tonometry
Red free filter
Rose-bengal staining

38. Accessory devices
Specialized examinations can be perform by slit
lamp biomicroscope with the help of some
accessory devices. These are:
Gonioscopy
Pachymetry
Applanation tonometry
Ophthalmo dynamometry
Slit lamp photography
Slit lamp videography
Laser interferometry
Slit lamp as delivery system for
argon, diode and YAG laser

39. Ophthalmologic uses of
slit lamp biomicroscope
Diagnostic uses
Therapeutic uses
Procedures

40. Diagnostic uses
Anterior segment
1. Eye lid- to determine blepharitis, stye
2. Eyelashes- pediculosis, distichiasis
3. Conjunctiva- scarring, conjunctivitis, pattern of
congestion
4. Cornea-thickness, bullae, K.P, infiltratre
5. Anterior chamber- regularity, any pathology
6. Iris and pupil- appearance, colour, synechiae,
neovascularization, iridodonesis, coloboma
7. Lens- grading and staging of cataract,
phacodonesis, position of lens

41. Posterior segment
1. To see the vitreous, media, optic disc,
macula, background retina
2. To differentiate position of pathology
3. Any macular degeneration
4. Retinal detachment

42. Procedures by slit lamp
1. Applanation tonometry
2. Gonioscopy
3. Contact lens fitting

43. Therapeutic uses
1. Removal of corneal F.B
2. Epilation