Ocular Imaging Flashcards
Layers of the retina in OCT (11)
- ILM
- NFL
- GCL
- IPL
- INL
- OPL
- ONL
- ELM
- Photoreceptors
- RPE
- Choroid
OCTs work by?
Recording the optical properties of ocular tissues
TSNIT curve represents?
Peripapillary circular measure of the thickness of the RNFL
A ___coloured flag on an OCT means that the area highlighted is?
a) Red
b) Green
d) Pink
e) Yellow
a) red: bottom 1% of values in comparison to normal thickness
b) green: 5-95%
c) pink: top 99%
d) yellow: 1-5 and 95-99%
In OCT, which areas are dark - the plexiform or nuclear layers?
Nuclear
Optimal is good in diagnosing peripheral or central retina?
peripheral
Pentacom images? (3)
Topography and elevation of the anterior and posterior corneal surface and the corneal thickness
Ultrasound biomicroscopy images?
Lesions behind the posterior pigmented epithelium of the iris
Why use ultrasound and not OCT?
OCT can’t penetrate dense layers like the storm and posterior pigmented epithelium of the iris
Indications to use ultrasound biomicroscopy?
cysts/tumours (iridociliary cysts)
vitreous haemorrhage
retinal tears
plateau iris syndrome
Electrophysiology (ERG) when want to?
assess function of retina e.g. photoreceptor response
VEP is used when want to see if there are what problems between where?
Retina and visual cortex
B-scan ultrasonography- when do you use it?
when can’t directly visualise ocular structures
B-scan ultrasonography- examples of when you would use it? (6)
- corneal opacities
- lid problems
- mitosis
- dense cataracts
- vitreous opacities
- hypopyon
ETDRS map represents?
The macular map broken down to 9 zones
