PRACT TEST SLE

Question 1

what is the purpose of parallelpiped (direct and retro illu)?

Answer 1

Purpose: The parallelepiped can provide an overview of the ocular structures
such the eye lids, palpebral conjunctiva, etc (similar to diffuse illumination), allow “some” 3D overview of the cornea and crystalline lens.

Question 2

what is the set up of parallelpiped (beam width, height, angle, magnification)

Answer 2

Width 2-3mm

Height Maximal

Angle 30° to 45°

Magnification Low-Medium (6x to 10x

Question 3

what is the purpose of van herick angle?

what is the set up (beam width, height, angle, magnification)

Answer 3

access the anterior chamber depth and screen patients with risk factors for angle closure glaucoma

width: narrowest
height: max
angle: 60
magnification: medium, 10-16x

Question 4

what is the purpose of optical section (cornea)?

what is the set up (beam width, height, angle, magnification

Answer 4

Purpose: to assess and judge the depth of a foreign body/ lesions in the cornea

width: narrowest
height: max
angle: 30-45
magnification: med-high (16-40x)

At high mag, we can see layers of cornea in the beam

Question 5

what is the purpose of optical section (crystalline lens)?

what is the set up (beam width, height, angle, magnification)

Answer 5

assess the location of the lens opacity - and hence determine
the type of cataract (i.e. anterior/ nuclear/ posterior/ cortical

Width: Narrowest
Height: Maximal
Angle: ~30 to 45°
Magnification Med-High (16x to 40x

Question 6

what is the purpose of conical beam?

what is the set up (beam width, height, angle, magnification, illumination)

Answer 6

to look for any signs of inflammation caused by uveitis of flare (protein) or cells
(white blood cells) in the anterior chamber, mostly used fir grading rather than detection.

Width: 1mm
Height: 1mm
Angle: ~45°
Magnification Med-High (16x to 40x)
****ROOM MUST BE DARK

Question 7

what is the purpose of specular reflection?

what is the set up (beam width, height, angle, magnification,) what is the one thing you have to take note of!!!

Answer 7

Purpose: to examine the endothelium for polymegathism (cell size variability)
and pleomorphism (cell shape variability), and the precorneal tear film

Width: 2-3mm
Height: Variable
Angle: ~45 to 60°
Magnification High (40x)
***For this technique to work, the angle of incidence = angle of
reflection.

So this means, it can ONLY be focus through ONE eye piece

Question 8

what is the purpose of sclerotic scatter?

what is the set up (beam width, height, angle, magnification,)

Answer 8

Purpose: useful to view subtle corneal changes such as oedema, scar, striae,
foreign bodies, etc.)

Width 1-2 mm
Height Maximum
Angle ~45° (decouple)
Magnification Low
beam placed on limbus