Testing for Eye Diseases Flashcards
What is a visual field test used for?
help the doctor find early signs of disease
How is a visual field test set up? 2
-dimly lit room
-2-d map of px’s entire area of vision.
What is a blind spot also known as and what does is it?
scotoma - marks a physiologic blind area of the retina
How many types of scotoma are their and their names?
Central
Pericentral
Paracentral
Cecal
Nerve fiber bundle (arcute,bjerrum,comet type)
What does central scotoma involve?
Involves the fixation area and is always associated with a loss of visual acuity
What does the pericentral scotoma involve?
Fixation area is relatively clear and the field immediately surrounding it is
deficient
What does the paracentral scotoma involve?
The area of depressed visual field is to one side of fixation
What does the cecal scotoma involve?
Involves the area of the normal blind spot
What does the Nerve fiber bundle (arcute,bjerrum,comet type) scotoma involve?
This type of lesion extends around the fixation point from the blind spot in an
arc and ends typically on the nasal field with a sharply demarcated border
What is the confrontation test? 2
-test 4 quadrants of visual fields
-can be done anywhere with no special equipment
What is an amsler grid?
a chart that consists of vertical and horizontal with a central fixation dot.
What does the amsler grid help detect?
abnormalities
in the central 20 degrees in the field of
vision
What does OCT stand for?
Optical Coherence Tomography
What is a OCT scan? 3
-high-resolution cross-sectional imaging of the internal structures of the eye.
-noncontact imaging.
-It is 1 to 2 orders finer than the use of ultrasound, (MRI), or computed tomography
What parts of the eye can the OCT scan? 6
-cornea thickness
-anterior chamber
-optic disc
-nerve fiber layer (retina)
-macula
-vitreoretinal relationship
What is a tonometery?
a diagnostic test that measures the
pressure inside your eye – it measures IOP
what condition can tontometry help in detecting?
glaucoma
A tonometry is a non invasive device that works via either an
indentation or an applanation principle. True/false
true
What is a gonioscopy?
Clinical technique used to examine the structures of the anterior chamber angle
Gonioscopy helps differentiate between the two main types of glaucoma. T/F
TRUE
What are the two major types of lenses used in gonioscopy?
direct goniolens
indirect mirrored lens
When is the direct goniolens used?
primarily for infants
How does indirect mirrored lens (gonioscopy) work?
the light rays are reflected by mirrors in the contact lens
What does a pachymeter measure and why is it used (2)?
corneal thickness to diagnose different diseases or before cornea surgery
