OCT

Question 1

What light does OCT use

Answer 1

Infrared

Question 2

What is interferometry

Answer 2

Light beam is split into 2 beams
One beam is sent and reflected off the ocular structures
The other is reflected off a reference mirror

Time domain - reference mirror is moved - when the time travelled between the reference beam and retinal /object beam match, an interference pattern is createdW

Question 3

What are causes of reduced image quality in OCT

Answer 3

Corneal or vitreous opacity
Small pupil
Non cooperative patient

Question 4

Where are retinal ganglion cells found

Answer 4

50% in the macula

Question 5

What cells does glaucoma affete

Answer 5

Macula retinal ganglion cells

Question 6

What OCT for RGC damage

Answer 6

Spectral domain OCT - assessment of individual layers in the maculaW

Question 7

What is the gangion cell complex

Answer 7

RNFL, GCL, IPL

Question 8

What is OCTA for

Answer 8

Non-invasive technique to visualise the vasculature of the retina and choroid

Multiple OCT B scans taken at the same point in the retina

Higher imaging speeds
Good at detecting abnormal choroidal vessels

Question 9

What layers are drusen found

Answer 9

RPE/Bruchs

Question 10

What layer are hard exudates found

Answer 10

Outer nuclear/outer plexiform

Question 11

What layers are flame Haem found

Answer 11

RNFL

Question 12

What layer are microaneuryms found

Answer 12

Inner plexiform/ inner nuclear

Question 13

What layer are cotton wool spots found

Answer 13

RNFL