Diagnostic Testing Flashcards
What are the 3 main machines for Laser Scanning Imaging?
Scanning Laser Polarimetry (SLP), Confocal Laser Scanning (CLST) and Optical Coherence Tomography (OCT)
SLP works by what type of phenomenon? This phenomenon results in what?
Bifrefringence Phenomomen, results in a phase change between beams
A GDX pro is the most recent type of ___? This machine ____ corneal compensation.
Type of SLP
Enhances corneal compensation.
An SLP uses polarized light to measure the thickness of the ____ ___ as part of a glaucoma workup.
retinal NFL
What is the wavelength of the fixation laser and imaging laser in a Zeiss-Meditec GDX?
Fixation Laser: 635nm (visible red)
Imaging Laser: 785 nm
How many normal subjects were found in the GDX RNFL normative database? What ages?
251 Normal Subjects (mostly caucasian and asian)
Ages: 18-82
The GDX Nerve Fiber Index (NFI) tells the doctor what?
How likely it is for the pt to get glaucoma.
95% of the normal population shows GDX VCC NFI values under __?
30
On the GDX-Pro, the guided professional analysis (GPA) have 4 colors. What are they and what do they mean?
Gray = no progression Yellow = Possible progression Red = Likely Progression Purple = Possible Increase
The GDX NFI database uses how many subject? What type of subjects?
432 subjects
243 normal
189 glaucoma
What NFI value indicates no glaucoma?
no glaucoma is <30
What NFI value indicates borderline glaucoma?
borderline glaucoma is 30-50
What NFI value is consistent with glaucoma?
glaucoma is >50
Quality (q) greater than or equal to ______ is a reliable scan
7
What is an example of confocal laser scanning tomography (CLST)?
Heidelberg retinal tomography - HRT
