Macula Retinal Imaging

Question 1

What does red-free photography give a better view of?

Answer 1

Vasculature

Question 2

How can you reduce a small pupil artefact on fundus photography?

Answer 2

Lights off
Allow time to redilate between eyes
Adjust alignment/fixation
Dilate

Question 3

How can you reduce an exposure artefact on fundus photography?

Answer 3

Adjust flash accordingly
Adjust image brightness accordingly

Question 4

How can you reduce an opacity/fixation/focus artefact on fundus photography?

Answer 4

Give clear instructions
Use different fixation target
Dilate

Question 5

What does an OCT A-scan measure?

Answer 5

Depth/reflectivity at one location
1D

Question 6

What does an OCT B-scan measure?

Answer 6

Forms cross-sectional image from A-scans
2D

Question 7

What does an OCT C-scan measure?

Answer 7

Combines B-scans to give cube scan
3D

Question 8

Why can false colour be helpful on OCT scans?

Answer 8

Shows up thin/faint structures

Question 9

What is good about greyscale viewing of OCT scans?

Answer 9

Easy to identify retinal layers

Question 10

What are the retinal layers?

Answer 10

ILM
NFL
GCL
IPL
INL
ONL
OPL
OLM
PR IS
PR OS
RPE

Question 11

What can a cataract cause on OCT?

Answer 11

Shadows

Question 12

What can myopia cause on OCT?

Answer 12

Curved scan

Question 13

What do floaters look like on OCT?

Answer 13

Hyperreflective in vitreous

Question 14

What does a posterior hyaloid look like on OCT?

Answer 14

Hyperreflective line above retina

Question 15

What do exudates look like on OCT?

Answer 15

Near vessels
Hyperreflective
Shadow underneath
Higher than RPE

Question 16

What do drusen look like on OCT?

Answer 16

Local RPE elevation
May push RPE up

Question 17

What conditions are exudates associated with?

Answer 17

Wet AMD
Diab/hypertensive retinopathy

Question 18

What conditions are drusen associated with?

Answer 18

AMD
Retinal degeneration
Aging

Question 19

What does active choroidal neovasc look like on OCT?

Answer 19

Hyper reflective mass (new vessels) which can be entangled with RPE
Oedema adjacent

Question 20

What does inactive choroidal neovasc look like on OCT?

Answer 20

Hyper reflective mass
No oedema
Poss atrophy

Question 21

What does atrophy look like on OCT?

Answer 21

Reduced RPE reflectivity
Window defect (choroid and sclera brighter)

Question 22

What causes atrophy?

Answer 22

PR death
(dry AMD, trauma)

Question 23

What are the types of pigment epithelial detachment (PED)?

Answer 23

Drusenoid
Serous
Fibrovascular

Question 24

What does drusenoid PED look like on OCT?

Answer 24

RPE and drusen separation (due to osmotic pressure)
RPE irregular
Confluent drusen

Question 25

What does serous PED look like on OCT?

Answer 25

Dome shaped oedema due to fluid leakage (usually from choroid) RPE detachment Optically clear

Question 26

What does fibrovascular PED look like on OCT?

Answer 26

Dome shaped oedema with neovasc membrane RPE detachment Not optically clear

Question 27

What causes a macular hole?

Answer 27

Vitreo-macular traction during PVD when strong foveal attachment present

Question 28

What is an epiretinal membrane and what does it look like on OCT?

Answer 28

Thickening of anterior membrane Hyperreflective membrane