OPT 210 OCT NEW UPDATE WITH CORRECT ANSWERS!!
OCT noninvasively uses ____________________ light to capture micrometer resolution and
penetrate optical media to create cross-sectional data.
low-coherence, near infrared
How do we use an OCT to take an anterior segment scan?
separate lens attachment on OCTs to shift focus to anterior segment
What does an anterior seg OCT include?
nasal and temporal overview of cornea, iris, angle
What are 3 purposes of angle OCT?
1. estimate angle openness (alternative to gonio)
2. confirm iris approach
,3. measure angle in deg either algorithm or self-drawn from peripheral iris to a line
perpendicular to TM
How do we know a narrow angle on angle OCT?
< 15 deg
What are 2 quality considerations of angle OCT?
1. must include angle (where iris inserts into angle) w/o obstruction
2. must be able to recognize structures = start w/ scleral spur
What are 3 limitations of angle OCT?
1. can only scan 1 nasal and 1 temporal angle (angle is 360°)
2. unable to visualize amount of TM pigment
3. unable to visualize most abnormal findings (synechiae, neo, etc.)
, After finding the jutting out of the scleral spur, how do we locate the ciliary body on
angle OCT?
directly behind scleral spur, less hyperreflective (most of it will be behind iris)
After finding the jutting out of the scleral spur, how do we locate the trabecular
meshwork on angle OCT?
in front of scleral spur (hard to differentiate ant vs post), may also contain Schlemm's
canal as a dark spot/slit
How do we identify Schwalbe's line on angle OCT?
located on the AC side of cornea-to-sclera histological transition - may or may not be
obvious
Where is the best place to look to determine the iris approach?
peripheral iris, closest to the angle
What disorder is being shown here?
OCT noninvasively uses ____________________ light to capture micrometer resolution and
penetrate optical media to create cross-sectional data.
low-coherence, near infrared
How do we use an OCT to take an anterior segment scan?
separate lens attachment on OCTs to shift focus to anterior segment
What does an anterior seg OCT include?
nasal and temporal overview of cornea, iris, angle
What are 3 purposes of angle OCT?
1. estimate angle openness (alternative to gonio)
2. confirm iris approach
,3. measure angle in deg either algorithm or self-drawn from peripheral iris to a line
perpendicular to TM
How do we know a narrow angle on angle OCT?
< 15 deg
What are 2 quality considerations of angle OCT?
1. must include angle (where iris inserts into angle) w/o obstruction
2. must be able to recognize structures = start w/ scleral spur
What are 3 limitations of angle OCT?
1. can only scan 1 nasal and 1 temporal angle (angle is 360°)
2. unable to visualize amount of TM pigment
3. unable to visualize most abnormal findings (synechiae, neo, etc.)
, After finding the jutting out of the scleral spur, how do we locate the ciliary body on
angle OCT?
directly behind scleral spur, less hyperreflective (most of it will be behind iris)
After finding the jutting out of the scleral spur, how do we locate the trabecular
meshwork on angle OCT?
in front of scleral spur (hard to differentiate ant vs post), may also contain Schlemm's
canal as a dark spot/slit
How do we identify Schwalbe's line on angle OCT?
located on the AC side of cornea-to-sclera histological transition - may or may not be
obvious
Where is the best place to look to determine the iris approach?
peripheral iris, closest to the angle
What disorder is being shown here?
