Transcript Visante omni Basic Operation and Interpretation

Visante omni System
Comprehensive
Topography
Basic Operation
and Interpretation
Visante omni Course Outline
1. System Overview
2. Basic Operation
3. Understanding Comprehensive Topography Maps
4. Clinical Examples
Note:
This e-Learning Course is designed to be self-paced.
To advance the slide, press the Space Bar or click the mouse button.
Visante omni Course Outline
1. System Overview
2. Basic Operation
3. Understanding Comprehensive Topography Maps
4. Clinical Examples
What is Visante omni?
System that links
ATLAS Placido disk and
Visante OCT
technologies for
enhanced pathology
detection.
Visante omni combines
ATLAS anterior corneal
topography with
Visante OCT
pachymetry to provide
posterior corneal
topography.
Combining Placido Disk and OCT Technologies
V-Trac™ Registration:
Linking ATLAS and Visante OCT for Posterior Topography
Anterior Elevation from ATLAS Topography
x
1. Register Pachymetry at Corneal Vertex
2. Subtract Wall Thickness
3. Determine Posterior Elevation
Visante omni System Overview
–
Visante OCT Software Version 3.0 New Features:
–
Relative Pachymetry Map
–
Auto-alignment feature
–
New Optional Features in Software Version 3.0
–
Topography Link Software: Links ATLAS and Visante exams to create posterior topography
maps (Visante omni)
–
DICOM Gateway: Import a Modality Worklist and export DICOM reports/images to a DICOM
compliant device (such as ZEISS VISUPAC STAR or FORUM)
New Feature with Visante OCT 3.0 Software:
Reference Eye Image
Pressing the Reference Eye Image
icon will show the location of the
acquired OCT scans. This image
will print on OCT printouts.
New Feature with Visante OCT 3.0 Software:
Auto-Alignment
Visante OCT now can automatically track the cornea to simplify scan acquisition.
x
Align the vertex of the
cornea within the green
scan window.
Select “Auto-Align” and then click on the
center of the pupil. Visante OCT will now
adjust the chinrest to keep the corneal
vertex in the scan window.
New Feature with Visante OCT 3.0 Software:
Review ATLAS Exams
ATLAS Review Software now
appears on Visante
Select ATLAS
Exam.
Select
Photokeratoscope.
Visante omni Course Outline
1. System Overview
2. Basic Operation
3. Understanding Comprehensive Topography Maps
4. Clinical Examples
Always Acquire ATLAS exam first
1. Select patient on ATLAS and Press “Capture Image”
2. Capture Image on ATLAS and Select “Done”
Note for ATLAS 993/995 users:
After acquiring exams, you must return to
the MAIN MENU for ATLAS exams to
transfer to Visante OCT.
3. Patient Information and Exams are Automatically
Transferred to Visante OCT
ATLAS
993/995/9000
4. Select the patient from “View Today’s Patients” tab on
Visante OCT and select “Scan”
5. Select “LVC Comprehensive” Protocol
Select “LVC Comprehensive” Protocol. This Protocol
is designed to create Comprehensive Topography
Maps. It will only acquire Global Pachymetry Scans
and will automatically create Comprehensive
Topography Maps using the most recent ATLAS exam.
6. Acquire Global Pachymetry Map Scan using Auto-Align
Click on the
center of the
pupil.
Ensure that the corneal
vertex is in the green
positioning target
Select “Auto-Align” to
turn on the autoalignment feature.
Select “Acquire”
to acquire scan
7. Comprehensive Topography Maps Automatically Created
Select “File > Print” to
print the active Tab.
The Comprehensive
Topography tab is then
automatically created using
the last ATLAS exam acquired.
A window will appear to
select a different ATLAS
exam to link to the Global
Pachymetry scan.
To link other ATLAS exams
to the Global Pachymetry
Select “Scan Again” to acquire
scan, select
another Global Pachymetry Map if
“Comprehensive Map”
needed. Select “Continue” to scan
the other eye or to finish.
Visante omni Course Outline
1. System Overview
2. Basic Operation
3. Understanding Comprehensive Topography Maps
4. Clinical Examples
There are 3 pre-defined “Themes”
(Standard, Alternate, Holladay, and 2
Custom Themes) with a preset
selection of maps. The software will
always remember the last Theme
selected.
This slide reviews the
STANDARD Theme.
The maps on the left column are
the Anterior Axial Curvature and
Anterior
Mean
Maps
The map
onCurvature
the top right
is the
from
ATLAS.
Anterior Elevation Map from ATLAS.
For the STANDARD Theme, this is
expressed relative to a Best-Fit
Sphere.
The map on the bottom right is the Posterior
Elevation Map, from the combination of ATLAS
and Visante. For the STANDARD Theme, this is
expressed relative to a Best-Fit Sphere.
Note the solid band or “saddle” of elevation
across the cornea in this normal “with the rule”
astigmatism case. This is due to the use of a
spherical reference object, which results in
posterior elevation values of >15 μm in this
case in the mid-periphery.
The maps in the middle column
are the Pachymetry and Relative
Pachymetry Maps from Visante
OCT.
The HOLLADAY Theme was
developed in collaboration with
Jack Holladay, MD and contains
some specific differences from
the STANDARD Theme. For the HOLLADAY Theme, the
Anterior Elevation Map is expressed
relative to a Best-Fit Toric Ellipsoid,
which factors out the toricity and
asphericity of the normal cornea.
The Posterior Elevation Map is also
expressed relative to a Best-Fit Toric
Ellipsoid.
Note the improved fit and smaller
residual elevation values of ~4 μm
due to the improved fit of the toric,
ellipsoidal reference object.
Other key corneal data such as
These are
the simulated
minimum
pachymetry, white to These are the K values
keratometry
from and corneal using all the available
white,values
pupil diameter
ATLAS. aberration are provided. corneal data and the Q
spherical
value for the 4.5 mm Zone.
Corneal
Apex
Corneal
Vertex
Pupil Boundary
CursorCursor
Value
Thinnest
Point
To change any of the map
settings (such as displayed
map, colors, overlays), simply
right-click on the map.
Relative Pachymetry Analysis
•
Typical corneal thickness:
– 550 m centrally
– 700 m peripherally
•
Relative pachymetry shows the percent
deviation from typical corneal thickness
– GREEN is equal to typical thickness profile
– RED is thinner than typical
– BLUE is thicker than typical
•
Localized “hot spots” may indicate pathology
•
Changes in relative pachymetry greater than
~9% across the cornea (as seen in this Suspect
Keratoconus case) may suggest an abnormal
cornea
– +4% in periphery
– -8% at thinnest point
– 12% total change across cornea
-8%
+4%
Relative Pachymetry Examples
Typical Normal Cornea
Thin but Normal Cornea
Relative Pachymetry Examples
Thick but Normal Cornea
Abnormal Cornea (Suspect Keratoconus)
Guideline for Analyzing Visante omni
Comprehensive Topography Maps
Note: The following are general guidelines that may be used to assist with interpreting
Comprehensive Topography Maps, including Anterior Mean Curvature, Relative Pachymetry, and Toric
Ellipsoid Posterior Elevation. These are empirical guidelines based on early experience with Visante
omni and should not be considered definitive thresholds for clinical diagnosis.
Maximum Anterior
Mean Curvature
Change in
Relative Pachymetry
Maximum Posterior
Elevation
(% change across cornea)
(best-fit toric ellipsoid,
central 6 mm zone)
< 47 D
<9%
< 9 µm
Borderline
> 47 D and < 49 D
> 9% and < 12%
9 – 12 µm
Abnormal
> 49 D
> 12%
> 12 µm
Normal
Visante omni Course Outline
1. System Overview
2. Basic Operation
3. Understanding Comprehensive Topography Maps
4. Clinical Examples
Case 1: Normal Cornea
The maximum Anterior
Elevation (Toric Ellipsoid) is
less than 2 μm.
Mean Curvature eliminates corneal
astigmatism to reveal the local
average corneal curvature.
In this case, the Anterior Mean
Curvature Map is symmetrical and
normal, with a maxmum
curvature
The
maximum
Posterior
Relative
Pachymetry
reveals a
of 44.5 Diopters.
Elevation
(Toric
Ellipsoid)
cornea that is 8% thinner than
is also less
than 2 μm.uniform
typical,
but generally
and symmetrical.
Case 2: Irregular Astigmatism or Suspect Keratoconus?
Case 2 is Irregular Astigmatism, due to Normal Posterior
Elevation and Relative Pachymetry
The maximum Anterior
Elevation is less than 2 μm.
The maximum curvature on the
TheMap
maximum
Posterior Elevation
Anterior Mean Curvature
is slightly
lessRelative
than
consistent
with a
decentered, with aisvalue
of
47.54 μm,
Pachymetry
reveals
athinner
normalthan
cornea.
Diopters.
typical, but
otherwise normal cornea.
Case 3: Normal or Suspect Keratoconus?
Case 3 is Suspect Keratoconus, due to Noticeable
Posterior Elevation and Localized Thinning
The maximum Anterior
Elevation is only 4 μm.
The Anterior Mean Curvature Map is
slightly decentered, but is still
generally symmetrical. However, the
But the
maximum
maximum curvature
is high
(greaterPosterior Elevation is over
Pachymetry
reveals
μm at the Relative
same point
of localized
thinning.
than 4811Diopters).
localized
thinning
of
12%
This is consistent with Suspect Keratoconus.
across the cornea.
Case 4: Suspect Keratoconus due to Prominent Posterior
Elevation and Localized Thinning
The maximum Anterior
Elevation is 7 μm.
The Anterior Mean Curvature Map is
the maximum
Posterior Elevation is over 21
decentered with aAnd
maximum
curvature
Relative
Pachymetry
reveals
μmDiopters.
at the same point
of localized
thinning,
in excess of 49
localized
thinning
of
9%
across
consistent with Suspect Keratoconus.
the cornea.
Case 5: Suspect Keratoconus
The maximum Anterior
Elevation is over 21 μm.
The Anterior Mean Curvature Map
clearly highlights the localized
Relative Pachymetry reveals
maxmum curvature in excess of
48
localized
thinning
of 10%
The
maximum
Posterior
Elevation
Diopters.
across
is over 45 μm,
whichthe
is cornea.
clearly
abnormal
Case 6: Clinical Keratoconus
The maximum Anterior
Elevation is over 41 μm.
The Anterior Mean
Curvature Map clearly
highlights the 70
Diopter cone.
Relative Pachymetry reveals
Thesignificant
maximumlocalized
Posteriorthinning
across
the91cornea.
Elevation
is over
μm
Case 7: Pellucid Marginal Degeneration
The maximum Anterior
Elevation is over 41 μm.
The Anterior Mean
Curvature Map clearly
Relative Pachymetry reveals
highlights the decentered localized thinning of 11% across
Posterior
area of high local average The maximum
the
cornea.
curvature greater than 50 Elevation is over 70 μm
Diopters.