2 - Diagnostics - Part 2

Question 1

Why does ICG takes longer to leak through vessels?

Answer 1

Larger molecular weight.

With a larger molecular weight, it also has larger protein bounding thus leading to less leakage

Question 2

Occult CNV and pigment epithelial detachments can be seen better with?

Answer 2

ICG

Reason for this is due to larger wavelength is needed to penetrate to certain levels of tissue

Question 3

What diseases in the retina are indicative of ICG angiography?

Answer 3

Idiopathic Polypoidal Choroidal Vasculopathy, AMPPE, CSCR, Serpiinous choroidopathy MEWDS, birdshots and multifocal choroiditis.

Question 4

What drug is a contraindication for the usage of ICG?

Answer 4

Metformin - for DM II

Note: This is due to the fact that Iodine in ICG can be nephrotoxic. Metformin is excreted through the renal system which makes sense but there is an additional associationg of lactic acidosis caused by the Metformin (MALA)

Question 5

What type of OCT resolution determines accuracy with which size and separation of features can be identified?

Answer 5

Lateral resolution

Question 6

What is the function of Axial resolution?

Answer 6

Determines which layer can be distinguished.

Question 7

What are two main structures of a light source that Axial resolution require for imaging?

Answer 7

1. Wavelength of light source

2. Bandwidth of light source

Question 8

What is the newest technology for OCT imaging?

Answer 8

Swept source OCT

Question 9

What can be illuminated by auto-fluorescence; which can show an accumulation of what product related to phagcytosis of PR’s?

Answer 9

Lipofuscin

Question 10

What is the primary function of a Confocal Scanning Laser Ophthalmoscopy for?

Answer 10

Glaucoma

Question 11

What imaging system would you use for getting better resolution of RPE or Bruch’s?

Answer 11

Near infrared reflectance imaging

Note: CSCR detection is great way to use this technique

Question 12

What method is used for visualizing rod photorecptors?

Answer 12

Adaptive Optics

Question 13

What is the built in wave-front sensor inside of Adaptive Optics system?

Answer 13

Hartmann sensor

Question 14

B-scan with low frequency (1 to 5 MHz) will display what tissue?

Answer 14

Orbital Tissue and Abdominal

Question 15

B-scan with medium frequency (7 to 10 MHz) will display what tissue?

Answer 15

Retina, Vitreous and Optic Nerve

Question 16

B-scan with High frequency (30 to 50 MHz) will display what tissue?

Answer 16

Anterior chamber and Angle

Question 17

Increased gain, Increased tissue penetration and sensitivity are benefits of a B-scan but there is one disadvantage. What is that?

Answer 17

Decreased resolution

Question 18

What are the 2 documentation modes for B-scan?

Answer 18

1. Stationary/static

2. Moving or Dynamic

Question 19

What imaging system is excellent to observe Vitreous Hemorrhage?

Answer 19

Dynamic B-scan

Question 20

What B-scan method is used to observe ON and Posterior pole?

Answer 20

B-scan Logitudinal

Question 21

What B-scan method is used to only observe ON?

Answer 21

B-scan Axial

Question 22

What are the three types of ERG responses?

Answer 22

1. A - wave (late potential receptor)
2. B-Wave (ON bipolar cell)
3. Oscillatory wave (inner retinal movements)

Question 23

What is the rods response to a stimulus rated in Hz?

Answer 23

upto 20Hz (mostly 8Hz)

Question 24

In regards to ERG responses when are most clinical distinctions made base on magnitude?

Answer 24

Newborn