PPO

Question 1

Trapezoid mirror

Answer 1

Equator to PP (“mid-periphery”)

Question 2

Rectangular mirror:

Answer 2

Equator to ora (‘Periphery”)

Question 3

Gonio mirror:

Answer 3

CB, pars plana

Question 4

Measure ON size with 78D and 90D lens

Answer 4

78D= 1.2 conversion factor
90D = 1.33 conversion factor
66D lens gave a 1:0

Question 5

Elschnig Classification of ONH

Answer 5

Type I= a flat cross sectional
Type II= a cylinder cross sectional
Type III= a sloping cross sectional
Type IV= a sloping with hook cross sectional

Question 6

Patient Demographics and C/D Ratio

Answer 6

Average c/d for Caucasians: 0.4
Average c/d for African-Americans: 0.6
Average c/d for Asian/Latino: 0.5
Caucasians .3 with +/- .2 deviation
AA  .5 w/ +/- .15 deviation
Suspicious when the C/D is .1 larger than normal expectation

Question 7

False positive:

Answer 7

see something when it wasn’t there

Question 8

False negative:

Answer 8

patient reports seeing a light but does NOT report seeing an even brighter light

Question 9

High power lens gives

Answer 9

Low magnification

Increased FOV

Question 10

Low power

Answer 10

High magnification

Decreased FOV

Question 11

Volk G-3 mirror angles

Answer 11

D-shaped mirror: 60o
Rectangular mirror: 66o
Trapezoid mirror: 76o
Image magnification: 1.08%

Question 12

Tilted Disc:

Answer 12

The vertical axis itself is tilted

Disc appears to be tilted downward nasally

Question 13

Malinserted Disc:

Answer 13

The disc is tilted along its vertical axis
Disc appears to be tilted upward nasally
Nasal rim can be “heaped” up with temp depressed with scleral crescent

Question 14

20D lens magnification

Answer 14

3.13%

Question 15

Field of View

Answer 15

(inversely related to magnification) is around 8 DD* with a 20D lens