slit lamp

Question 1

slit lamp techniques are useful for?

Answer 1

• screening for eye complaints
• fitting contact lenses
• managing anterior and posterior eye disorders

Question 2

slit lamp consists of ?

Answer 2

illumination and observation system

Question 3

slit lamp is an important tool for the examination of the ____ and _____ segment of the eye

Answer 3

anterior

posterior

Question 4

the observation system is a?

Answer 4

high resolution microscope

Question 5

the illumination system is a?

Answer 5

focusable beam

Question 6

the rheostat voltage dial can help to

Answer 6

vary the slit height, width, angle, intensity

Question 7

what does acronym CRYND stand for?

Answer 7

Cobalt blue
Red free
Yellow
Neutral density
Diffuser

Question 8

what does the diffuser filter do

Answer 8

overview of the anterior eye and adnexa

Question 9

what does the yellow filter do

Answer 9

eliminates short wavelength light during fluoresceine examination

Question 10

what does the red free filter do

Answer 10

enhances contrast between blood vessels and surrounding ocular structures

Question 11

what does the neutral density filter do

Answer 11

if larger slit height/ widths are required then it reduces brightness

Question 12

what does the cobalt blue filter do

Answer 12

used in conjunction with sodium fluorescein (exciter)

Question 13

how is a sharp edge achieved in an illumination system

Answer 13

by using a physical aperture and optical system

Question 14

describe the eyepieces in slit lamp observation system?

Answer 14

parallel eyepieces

can be interchanged to provide increased magnification (10x/16x)

Question 15

how can magnification be modified in an observation system?

Answer 15

Turret= modifies magnification (6.3x, 10x, 16x, 25x, 40x)

flipper for 1x/ 1.6x magnification

Question 16

what can a reticle do

Answer 16

added to eyepiece for assessment of ocular structure size, shape

Question 17

what does the acronym RIDDSS stand for

Answer 17

Retro-illumination
Indirect illumination
Direct focal illumination
Diffuse illumination
Sclerotic scatter
Specular reflection

Question 18

diffuse illumination

Answer 18

low magnification 
high illumination
wide illumination beam/ diffuser
optimum beam  angle 45-60º
provides overview of eye and adnexa (lids, lashes, cornea, conjunctiva, iris, pupil)
often used for ophthalmic photography

Question 19

For ______ -______ illumination , the slit lamp ______ beam and _________ microscope are focussed at the ______ point.
It provides a ______ view of the cornea , _____ ______ and crystalline lens (or -______ lens) .
The more ______ the structure, the ______ the angle between ________ and _______ system.

Answer 19

direct focal
illumination 
observation
same
3D 
anterior chamber
intraocular 
anterior 
wider
illumination
observation

Question 20

Direct focal illumination - parallelepiped

Answer 20

3D view of cornea and crystalline lens 
at low to moderate magnification
low illumination
scans for fluorescein staining 
1-2mm slit beam width , max height
beam angle varies but optimum beam angle is 45-60º

Question 21

Direct focal illumination - optic section

Answer 21

narrow slit beam (,0.5mm, max height)
wide angle (60º) to facilitate depth estimation
assesses depth of opacity anomaly once detected with parallelepiped beam
illumination is moderate to high

Question 22

sclerotic scatter

Answer 22

produced by phonemenon of total internal reflection within cornea

a glow around cornea is present in a normal cornea

it is used for the presence of an opacity (central corneal oedema ) will lead to light scatter in that region

Question 23

indirect illumination

Answer 23

practitioner views structure to the side of the directly focussed section

slit lamp is decoupled

can be used to view the cornea where the direct focal illumination would bleach the area under examination

focal corneal oedema, corneal foreign bodies

Question 24

Retro illuminated

Answer 24

area of interest is illuminated by light behind the structure

cornea is retro illuminated by the iris

can e useful to view structures that would be bleached by DFI (gimbal vascularisation)

depending on magnification can be viewed with a coupled or decoupled system

Question 25

specular reflection

Answer 25

provides an adequate image of surface structure/ texture (pre corneal tear film, corneal endothelium)

observation and illumination systems are at equal angles to a perpendicular line relative to the structure

high magnification (25x to 45x)

superimposition of purkinje images