2. Slit lamp assessment is considered to be the
gold standard device for the assessment of
the anterior segment of the eye in clinical
practice
This is because they provide…
Excellent image quality
Stereoscopic image
Flexible illumination
Flexible magnification
Therefore there are many different uses
Even more when attachments are added
3. What are the uses of slit lamp
ownOn their With accessories
Routine examination
of anterior segment
Adnexa through to
anterior vitreous
Problem-based
examination of
anterior segment
Gonioscopy
Fundoscopy
Ocular photography
Contact tonometry
(Goldmann)
Direct contact
goniolenses
4. • The lamp facilitates an examination of
the anterior segment, or frontal
structures of the human eye which
includes the :
1. Eyelid &eye lashes
2. Cornea
3. Sclera
4. Conjunctiva
5. Iris
6. Aqueous
7. Natural crystalline lens and
8. Anterior vitreous.
5.
6. Basic Design
1. Viewing arm
Biomicroscope
Adjustable focus eyepieces
Magnification dial
2. Illumination arm
The “slit lamp”
Slit size, shape and filter controls
Variable size, shape, colour and brightness
3. Biomicroscope and illumination are mechanically
coupled around central pivot point (copivotal)
Both focus at the same point (parfocal)
Both arms can swing independently 180º along horizontal
– there is a scale in degrees
Both always central regardless of angle (isocentric)
4. Moveable base plate and joystick control
7. Types of illumination incorporated in slit lamp
1. Slit width
Wide- survey globe/cornea
Narrow- depth, width & position of small
abnormalities
beam as wide as cornea is thick
forms a parallelepiped volume: a box of
illuminated tissue is seen
Thin (slit)- narrowest beam forms an optical
section
so thin it's just discernible التمييز سهل
valuating small changes in clarity & pinpointing
الدقة depth of pathology
8. 2. Light-source intensity
Medium to high: most purposes
High: optical section
3. Filters
neutral, cobalt blue (for fluorescein), red-free
and red free filter (green filter).
4. Magnification
low power (~10x) is used for survey
medium to high (16-40x) for optic section &
parallelepiped
Higher than (40x) for specular reflection
normally, light is focused at same point as
microscope (“parfocal”)
9.
10. 1. Start with neutralizing the eye piece at zero if
the examiner has no refractive error or wearing
his glasses & lower powered objective lens .
2. Use lowest voltage setting on transformer
ensure open aperture
3. Select the longest slit length
4. Adjust chin rest :
Patient's eyes approximately with level of the
marker on head rest .
5. Lamp height of the slit beam centered vertically
on Patient's medial canthus
6. Focus by moving joystick
How the examiner can adjust and use the slit lamp
11. locking nut: loose for free
movementOcular focus to 0
adjust beam height for tall,
narrow vertical beam
adjust width for narrow beam w/
good illumination
12. Methods of examination of slit lamp
without attachments
There are six basic methods of
illumination
1. Diffuse illumination
2. Direct focal illumination
3. Indirect illumination
4. Sclerotic scatter
5. Retro-illumination
6. Specular reflection
13. 1. Diffuse Illumination :
This method is done by using a wide slit
which slightly out of focus and this method is
used in examination of the iris and the adnexa
of the eye .
The slit should be wide and the magnification
should be low as possible to prevent loss of
field and enable large field of view .
14.
15. 2. Direct focal illumination :
•Illumination and observation are focused in the
same plane
•slit width narrow to broad
•Illumination angle 45° to 60°
•Magnification 10x-40x
This method is used to examine the cornea in
details , the anterior chamber , crystalline lens ,
anterior part of the vitreous and in determine if
there is flare , pus or blood cells in the anterior
chamber .
16.
17. 3. Indirect illumination :
•The beam is focused in an area
adjacent to ocular tissue to be observed
•Decentered beam
•Illumination 2 to 4mm slit
•Magnification: Low to medium
(depending upon object size).
This method is used to determine if
there is infiltrates رشح , corneal scars ,
deposits ترسبات and epithelial and
stromal defects .
18.
19. 4. Sclerotic scatter :
•Light incident on the limbus with 2-
4mm slit at an angle of 45° - 60°
•Decentered slit
•The microscope focused centrally
•Total internal reflection of the
incoming light at inner corneal
boundaries (endothelium and
epithelium) .
This method is used in examination of
scars, foreign bodies, corneal defects
and irregularities in the cornea .
20. 5. Retro-Illumination from the Fundus :
This technique is used to observe media claritiesصفاءand
opacities
•The pupil is dilated
•the slit beam and microscope are made co-axial and light
strikes the fundus and creates a glow behind the opacity in
the media
•The media opacity creates a shadow in the glow
Applications
•abnormities in the anterior vitreous, lens, anterior
chamber, cornea
21.
22. 6. Specular Reflection: it is useful slit lamp
technique for scrutinsing the corneal endothelium ,
the tear film surface , crystalline
lens and other surfaces .
A bright reflection will be observed in the anterior
surface and less bright reflection will be observed in
posterior surface of the cornea .
The illumination is narrow parallelepiped and the
microscope is placed directly in front of the eye with
the light source 25degree from the microscope .
The endothelium will appear clear and rough surface (
due to individual endothelial cells ) .
23.
24. Attachments of the Slit lamp
There are many different attachments and
accessories,of these :
1. video attachment :used to facilitate teaching of slit
lamp .
2. Goldman tonometer :used in measuring the intra
ocular pressure of the anterior chamber .
3. Gold 3-mirror lens : used in measuring the angle
of the anterior chamber and center of the retina .
25. 4. Volk double aspheric lens
(+60,+78,+90) :used in examination
the fundus os the patient indirectly .
5. Direct contact goniolenses : for
examination of the periphrey of the
fundus .