OCULUS Corvis® ST
Corneal Visualization
Scheimpflug Technology
OCULUS Corvis® ST
Evaluation of corneal biomechanical response,
tonometry and pachymetry
The revolutionary Corvis® ST records the reaction of the cornea to a defined air pulse using a
newly developed high-speed Scheimpflug camera. This camera captures over 4 300 images per
second, permitting highly precise measurement of IOP and corneal thickness. Based on a video
of 140 images, taken within 31 ms after onset of the air pulse, the Corvis® ST provides a
detailed assessment of corneal biomechanical properties.
The information obtained on the biomechanical response of the cornea is used to calculate
a biomechanically corrected IOP (bIOP). Furthermore it allows ectatic diseases such as
keratoconus to be detected at a very early stage. Biomechanical properties also play an
important role in the development and progression of glaucoma.
A high-speed Scheimpflug
camera takes more than
4 300 images per second
13.282 ms 15.114 ms 17.175 ms 19.007 ms 21.068 ms 22.900 ms 24.961 ms
IOP/Pachy Display
Biomechanically corrected IOP (bIOP)
bIOP readings are less dependent on biomechanical properties and corneal thickness and hence more accurate
than IOP readings. The data are easy to read and interpret, and the IOP follow-up chart is neatly arranged.
IOP correction is based on corneal thickness, age
and the biomechanical response of the cornea.
When calculated this way bIOP is less influenced by
corneal properties and thickness than it is with other
measurement methods. As the Corvis® ST measures
both biomechanical response and corneal thickness
with high precision, the device is able to correct for
both factors at the same time.
Due to the measurement principle, it delivers bIOP
values uninfluenced by the tear film. This and the fast
auto tracking and auto release ensure highly repeatable,
user-independent IOP and thickness readings.
Biomechanical
IOP follow-up bIOP/CCT measurements response video Pachymetric progression
Vinciguerra Screening Report
Corvis Biomechanical Index (CBI)
This module provides comprehensive biomechanical screening and keratoconus detection.
The software displays the patient’s results against normative values in easy-to-grasp charts.
The Vinciguerra Screening Report allows fast and
comprehensive screening for corneas with abnormal
corneal biomechanical properties. It is the first available
screening software that combines biomechanical
information with pachymetric progression data. It
calculates the Corvis Biomechanical Index (CBI), which
enables the detection of ectatic corneas based on these
findings. As keratoconus is caused by biomechanical
changes and leads to progressive thinning, the software
is able to detect the earliest signs of this disease.
Furthermore, the normal ranges of dynamic corneal
response (DCR) parameters are shown as a function
of bIOP and time. Standardized parameters indicate
whether the cornea has a normal biomechanical
response.
Biomechanical Normal ranges of dynamic Standard deviation for Corvis
response video corneal response (DCR) screening parameters Biomechanical
parameters Index (CBI)
Biomechanical Keratoconus Detection with the CBI
More information spells greater safety
The Vinciguerra Screening Report performs biomechanical screening based on the dynamic corneal response,
enabling the examiner to understand the stress-strain behaviour of corneal tissue and assess ectasia risk.
Compare with healthy patients Measure corneal elasticity Detect keratoconus early
The grey boxes show for each screening parameter how Stress-strain curves describe the elastic properties of the The Corvis Biomechanical Index (CBI) is based on a
many standard deviations (SD) the parameter deviates cornea. The curves are shifted to the right if the cornea logistic regression approach and was developed to
from the mean of healthy patients. Positive values is soft and to the left if the cornea is stiff. detect keratoconus at an early stage. It is based on five
indicate softer tissue, negative values stiffer tissue than The stress-strain index (SSI) describes the position of Dynamic Corneal Response parameters and gives a
in the average healthy patient. the curve. A value of 1 indicates the average elasticity score from 0 (low ectasia risk) to 1 (high ectasia risk).
of a healthy 50-year-old patient. A value smaller than 1
White area: within ± 1 SD indicates a softer and a value greater than 1 a stiffer
Light grey: between 1 - 2 SD than average behaviour.
Dark grey: more than 2 SD
Pentacam® and Corvis® ST Work Together
Artificial intelligence approach for enhanced ectasia detection
Gain accuracy in ectasia risk assessment by integrating tomographic data from the Pentacam® and biomechanical data from the Corvis® ST.
Combining tomography with biomechanical Big data and artificial intelligence
properties provides the highest sensitivity
The TBI is based on an artificial intelligence algorithm using tomographic and
biomechanical data. In 2022, the TBI algorithm was refined on the basis of a data set
Linking the Pentacam® and Corvis® ST together is very easy. Just connect both
of 22 clinics from around the world. Using the data from 1680 normal patients (N),
instruments to the same computer or connect them via your clinic network.
1181 "bilateral" keratoconus patients (KC), 551 topographically normal eyes of very
The rest is done automatically: Pentacam® and Corvis® ST measurements are combined
asymmetric ectasia patients (VAE-NT) and 474 non-operated ectatic eyes (VAE-E) from
and the TBI is calculated automatically. This works with any Pentacam® model*.
the VAE-NT patient group enabled the optimization of detection of keratoconus at an
* A license for the Belin Ambrósio Enhanced Ectasia Software is required. early stage. This study1 was one of the largest of its kind and has now been published.
1
Ambrósio R Jr, et al. Optimized Artificial Intelligence for Enhanced Ectasia Detection Using
Scheimpflug-Based Corneal Tomography and Biomechanical Data. Am J Ophthalmol. 2023
Jul;251:126-142. doi: 10.1016/j.ajo.2022.12.016. Epub 2022 Dec 19. PMID: 36549584.
Patient Data
Pentacam® measurement data Pentacam® tomographic data
Management
Tomographic
Biomechanical
Assessment
Clinic network
Viewing stations
Pentacam® Corvis® ST
Tomographic and Biomechanical Assessment
Tomographic Biomechanical Index (TBI)
Integration of Pentacam® data for a combined tomographic and biomechanical analysis. The best of two worlds:
TBI is calculated using an artificial intelligence approach to optimize ectasia detection.
By combining tomographic data from the Pentacam®
with biomechanical data from the Corvis® ST one
can further improve sensitivity and specificity in
the detection of patients with a significant risk
for developing ectasia after refractive surgery. The
outcome of this analysis is supplied by the Tomographic
Biomechanical Index (TBI). This index together with the
comprehensive display helps you to avoid risks and to
treat more patients safely.
Screening values in
comparison to populations Tomographic Belin / Ambrósio
of healthy (green) and Biomechanical D value 4 Maps Refractive
keratoconic (red) patients Index (TBI) (Pentacam®) (Pentacam®)
Biomechanical Analysis After Laser Vision Correction
New CBI-LVC
The CBI-LVC measures biomechanical stability after laser vision correction. This information is key for making
clinical decisions such as on retreatments after LASIK or corneal crosslinking in case of ectasia.
Various preoperatively screening methods are available
for analyzing the risk for developing ectasia after
laser vision correction. However, the possibilities
for postoperatively evaluating ectasia risk based on
objective criteria are still limited to date.
This software allows automatic assessment of
postoperative biomechanical stability. The normative
data for stable post-op cases are represented by the
green curves, while the red curves represent post-LVC
ectasia cases.
Treated corneas are automatically recognized as
such and analyzed against post-LVC normative data.
Alternatively the user can manually select the option
of analyzing a treated cornea.
As its final output the CBI-LVC estimates a patient’s
risk of developing ectasia after laser surgery.
NEW: Selection of Selection of
the reference database
database (global or (untreated or Normative data for DCR parameters for stable (green)
East Asian patients) post-LVC) post-LVC or post-LVC ectasia cases (red)
BEST Display
Homburg Biomechanical E-STaging Display: quantification of early biomechanical changes
Detecting biomechanical changes over time: Keratoconus progression and early signs of improvement after
corneal crosslinking can only be detected by visualization and quantification of biomechanical changes.
Visualization and quantification of biomechanical
changes over time is an essential precaution in various
clinical applications. Progression of keratoconus must
be detected at a very early stage if a severe loss of
vision is to be prevented.
Another important feature is to verify the success
of treatment after corneal crosslinking. Whereas
topographic changes only occur after several months,
biomechanical changes can be measured with the
Corvis® ST already four weeks after the procedure.
The BEST Display is the ideal solution for monitoring
biomechanical changes over time. It enables you
to analyze the progression, related to a baseline
measurement.
Time of crosslinking procedure
See the change of the data Superimposition of the Keratoconus staging (E-Staging)
compared to a baseline exam biomechanical response videos based on biomechanical response
of measurement A (red) and
measurement B (blue) Stress-strain behaviour for all selected exams
Glaucoma Screening Software
Biomechanical Glaucoma Factor (BGF)
This revolutionary software allows an easy screening for glaucoma based on the biomechanical response. It offers
a new approach to detecting normal tension glaucoma (NTG) cases despite normal intraocular pressure.
Detecting normal tension glaucoma (NTG) is very
challenging in clinical practice. Intraocular pressure
measurement will not indicate any elevated risk for
glaucoma, and the optic nerve head might also
appear relatively normal.
It recently has been shown that biomechanical
properties can serve as an independent risk indicator
for NTG. This provided the basis for the development
of the Biomechanical Glaucoma Factor (BGF).2
The BGF is a very early risk indicator of NTG which will
guide you to the best clinical decisions for your patient.
2
Pillunat KR, et al. A new biomechanical glaucoma factor to discriminate
normal eyes from normal pressure glaucoma eyes. Acta Ophthalmol. 2019
Nov;97(7):e962-e967. doi: 10.1111/aos.14115. Epub 2019 Apr 24. PMID:
31016882
Distribution of BGF in healthy Output of the
eyes (green) and NTG patients Biomechanical
bIOP/CCT (red). The black line shows the Glaucoma Factor
IOP follow-up measurements BGF-output for this patient. (BGF)
The World of the Corvis® ST
Discover new possibilities for you and your patients!
The brains behind the software
”Corneal biomechanics has demonstrated to be ”Why are corneal biomechanics important to the
synergic to shape analysis for providing an enhanced clinician? Clinical uses range from screening for
method to characterize ectasia susceptibility. The diseases such as keratoconus and glaucoma, to
integration of corneal tomography and biomechanical overcoming the errors in measurement of IOP using
data with artificial intelligence is currently the most the common applanation tonometer, to predicting
accurate approach for the diagnosis of keratoconus responses to corneal procedures such corneal collagen
and ectasia risk before any refractive procedure.“ crosslinking (CXL) and laser vision correction (LVC).“
Renato Ambrósio Jr, Brazil Cynthia Roberts, USA
”The focal reduction of corneal biomechanical ”Assessment of the biomechanical stability after
properties was shown from previous studies to be refractive surgery is critical to assess ectasia risk
the “first hit” in the development of keratoconus. The post laser vision correction. The CBI-LVC provides
Overview Corvis Biomechanical Index (CBI) has demonstrated an objective (the only available screening in these
Standard software to be highly sensitive and specific in multiple conditions in my knowledge) measure about the state
independentstudies for the diagnosis of keratoconus of the cornea post-operatively. This is very important
Biomechanical corrected IOP (bIOP) and early ectasia.“ for clinical decisions such as re-treatments, regular
Corneal thickness follow-up measurements or corneal crosslinking.“
Pachymetric progression Riccardo Vinciguerra, Italy
Biomechanical response video Paolo Vinciguerra, Italy
Dynamic corneal response software (optional)
Vinciguerra Screening Report (CBI) ”The Stress Strain Index estimates the mechanical ”The Corvis ST provides an IOP measurement that has
Tomographic Biomechanical Assessment (TBI) behaviour of the cornea in vivo and in real time. This been shown experimentally and clinically to be almost
Post laser vision correction analysis (CBI-LVC) parameter provides a clear indication of how soft completely independent of corneal biomechanics and
Homburg Biomechanical E-STaging Display (BEST) or stiff a cornea is, points at the risk of developing could therefore assist the management of glaucoma.“
Stress-strain curves and SSI keratoconus or post-refractive surgery ectasia and
assesses the effectiveness of collagen cross-linking Ahmed Elsheikh, UK
Glaucoma screening software (optional) in stiffening corneal tissue.“
Screening for normal tension glaucoma (NTG) -
Biomechanical Glaucoma Factor (BGF) Bernardo Lopes, UK
Stay tuned at www.corneal-biomechanics.com
OCULUS Corvis® ST
Technical Data
Tonometer
Measurement range 6 - 60 mmHg
Measurement distance 11 mm (0.4 in)
Inner fixation light Red LED
3D auto tracking & auto release
Scheimpflug camera
Frame rate 4 330 images per sec
Measurement range 8.5 mm (0.3 in) horizontal coverage
Pachymeter measurement range 300 - 1 200 μm
Measuring points 576 per image (576 x 200 pixel)
Source of light Blue LED (470 nm UV free)
Technical specifications 538 mm
(21.2 in)
Dimensions (W x D x H) 266 x 538 x 495 - 525 mm (10.5 x 21.2 x 19.5 - 20.7 in)
Weight 14 kg (30.8 lbs)
Max. power consumption 26 W
Voltage 100 - 240 V AC
Frequency 50 - 60 Hz
Recommended computer specifications Intel® Core™ i5, 500 GB SSD, 8 GB RAM, Windows® 11, Intel® HD Graphics
(19.5 - 20.7 in)
495 - 525 mm
266 mm
(10.5 in)
W W W.O C U L US . DE OCULUS Optikgeräte GmbH
Postfach • 35549 Wetzlar • GERMANY
The availability of products and features may vary by country.
OCULUS reserves the right to change product specifications and
Tel. +49 641 2005-0 • Fax +49 641 2005-295 design. All information is valid at the time of printing (04/24).
Email: export@oculus.de • www.oculus.de
OC/1895/WZ/EN
The OCULUS QM system is certified in accordance
P/72100/EN
with ISO 13485 (MDSAP) and (EU) 2017/745 (MDR) Find your local OCULUS representative on our website.
