OCT, HRT, GDx Flashcards
Measures the reflection of laser light (similar concept to ultrasound and reflection of sound)
OCT
Directly measures the thickness of the NFL
OCT
TD-OCT
Time domain OCT
SD-OCT
Spectral domain OCT
- most common
- newer
- aka HD-OCT
Greater speed in capturing images and higher definitaiton. Also different algorithm than TD-OCT
OCT OU report: key parameters
Compared to normative data base, are displayed in table formats
Small disc
<1.5mm
Medium disc
> 1.5
<2.5
Large disc
> 2.5
Colors on OCT data
GRY based on comparison to normative database
-only for >18 yo
Gray color on OCT
Not compared to normative database
-disc area ranges from normative database
Disc area ranges from normative database
1/3 < 1.58mm
1/3 are 1.58-1.88
1/3 >1.88mm
Gray when disc area is <1.3mm OR >2.5mm
What does the table tell you on OCT
Average NFL RNFL symmetry Rim area Disc area Average CD ratio Vertical CD ratio Cup volume
White
The thickets 5% of measurements fall here
Green
90%
Yellow
5%
Red
1%
Normative data for different ages
Will be differ. Just because someone has the same numbers as someone else, it will be different based on their age
RNFL OCT report
Thickness map is a topographical display of RNFL. An hourglass Shaw of yellow and red colors is typical of normal eyes
RNFL deviation map
Shows deviation fro normal. OCT en face fundus image shows boundaries of the cup and disc and the RNFL calculation circle
Neurotrophic retinal rim thickness OCT report
It is matched to normative data
RNFL TSNIT graph
Displays patients RNFL measurements along the calculation circle, compared to normative data
RNFL quadrants an clock hour
Average thickness is matched to normative data
When looking at the pie chart on the OCYT report, what are we paying attention to
Is there a difference between each eye and between visit to visit
• worry from 7-12 numbers difference in the quads and between visit to visit
Horizontal and vertical B scans
Extracted from the data cube through the center of the disc. RPE layer and disc boundaries shown in black. ILM and cup boundaries are shown in red