Computer-based Screening for Diabetic Retinopathy
| Status: | Completed |
|---|---|
| Conditions: | Ocular, Diabetes |
| Therapuetic Areas: | Endocrinology, Ophthalmology |
| Healthy: | No |
| Age Range: | 18 - 65 |
| Updated: | 4/2/2016 |
| Start Date: | August 2012 |
| End Date: | June 2015 |
| Contact: | Richard VanNess, MS |
| Email: | rvanness@visionquest-bio.com |
| Phone: | 505-508-1994 |
Phase 0 Observational Study of a Computer-based Screening Algorithm for Detection of Diabetic Retinopathy
The study is an Observational, Phase 0 designed to establish that the risk for diabetic
retinopathy assigned by the RiskAnalyzer improves the reading accuracy and consistency of
any reader and it decreases the inter-reader variability.
Objectives: Objectives one, two, and three are arranged chronologically and in an increasing
level of complexity as a three tiered approach to support the primary and secondary endpoint
of the trial. Objective one is to test fully each system components of the study limited to
a single site. Objective two is to evaluate the efficacy of the RiskAnalyzer to assign the
risk of Diabetic Retinopathy in comparison to the gold standard. Objective three is to
demonstrate that the reader's accuracy in grading images is improved when risk levels
assigned by the RiskAnalyzer are made available to the reader while performing the grading
of the images which is the primary endpoint of the trial Methods and Research Design: A
network of clinical study sites will be established to meet the required number of cases
needed as calculated by statistical analysis. Male and Female Subjects between the ages of
18-65 who are either pre-diabetic or diabetics will be eligible for participation in this
study. Subjects will be recruited, consented, photographed and their images graded by two
trained readers and analyzed by the RiskAnalyzer . The risk levels that are obtained from
the RiskAnalyzer will be compared to the current gold standard practice, manual grading of
each case by a reader. Data collected during this clinical trial will be reported to the
referring physician in the form of a retinal screening report completed and signed by a
licensed Ophthalmic professional and delivered to their attending physician. Risk levels for
diabetic retinopathy obtained by use of the RiskAnalyzer will not be given to the attending
physician under any circumstances in order to preserve standard of care for the patient.
The sensitivity, specificity, receiver operating characteristic (ROC), and data flow process
of the RiskAnalyzer, retinal image reading system will be analyzed and based on the current
gold standard of a human reader. This study is a three-aims study, 24 month in length,
prospective, case-only study of the performance of the RiskAnalyzer. The risk levels
obtained from the RiskAnalyzer are not made visible, i.e. are not unmasked to either of the
two readers. In year two, the risk levels obtained from the RiskAnalyzer for half of the
studies are unmasked to the two readers while grading the image.
Access to all study data and processes follows a role-based design. The clinical staff will
have access only to clinical data but not the technical data. The technical team will have
access to the technical data only but not the clinical data. The study coordinator will have
access to all data. The use of computers will adhere to the Guidance for Industry
Computerized Systems Used in Clinical Investigations and applicable sections of 21 CFRs part
11.
retinopathy assigned by the RiskAnalyzer improves the reading accuracy and consistency of
any reader and it decreases the inter-reader variability.
Objectives: Objectives one, two, and three are arranged chronologically and in an increasing
level of complexity as a three tiered approach to support the primary and secondary endpoint
of the trial. Objective one is to test fully each system components of the study limited to
a single site. Objective two is to evaluate the efficacy of the RiskAnalyzer to assign the
risk of Diabetic Retinopathy in comparison to the gold standard. Objective three is to
demonstrate that the reader's accuracy in grading images is improved when risk levels
assigned by the RiskAnalyzer are made available to the reader while performing the grading
of the images which is the primary endpoint of the trial Methods and Research Design: A
network of clinical study sites will be established to meet the required number of cases
needed as calculated by statistical analysis. Male and Female Subjects between the ages of
18-65 who are either pre-diabetic or diabetics will be eligible for participation in this
study. Subjects will be recruited, consented, photographed and their images graded by two
trained readers and analyzed by the RiskAnalyzer . The risk levels that are obtained from
the RiskAnalyzer will be compared to the current gold standard practice, manual grading of
each case by a reader. Data collected during this clinical trial will be reported to the
referring physician in the form of a retinal screening report completed and signed by a
licensed Ophthalmic professional and delivered to their attending physician. Risk levels for
diabetic retinopathy obtained by use of the RiskAnalyzer will not be given to the attending
physician under any circumstances in order to preserve standard of care for the patient.
The sensitivity, specificity, receiver operating characteristic (ROC), and data flow process
of the RiskAnalyzer, retinal image reading system will be analyzed and based on the current
gold standard of a human reader. This study is a three-aims study, 24 month in length,
prospective, case-only study of the performance of the RiskAnalyzer. The risk levels
obtained from the RiskAnalyzer are not made visible, i.e. are not unmasked to either of the
two readers. In year two, the risk levels obtained from the RiskAnalyzer for half of the
studies are unmasked to the two readers while grading the image.
Access to all study data and processes follows a role-based design. The clinical staff will
have access only to clinical data but not the technical data. The technical team will have
access to the technical data only but not the clinical data. The study coordinator will have
access to all data. The use of computers will adhere to the Guidance for Industry
Computerized Systems Used in Clinical Investigations and applicable sections of 21 CFRs part
11.
Sensitivity of retinal screening for risk stratification of DR using digital fundus
photographs with and without the assistance of the RiskAnalyzer
Sensitivity and specificity of retinal screening for risk stratification of DR using digital
fundus photographs and the RiskAnalyzer
Clinical Trial Methods and Research Design: A total of 10,000 subjects will be recruited to
participate in this study. These subjects will be enrolled through two parallel
collaborators, Extension for Community Healthcare Outcomes (Project ECHO) and CommuniCare
Health Centers. Each clinic will obtain approximately 50% of the cases per year or an
average of 50 cases per week. Subjects will be identified from clinics, CommuniCare Health
Centers of San Antonio, TX and Project ECHO, New Mexico. CommuniCare has two associated
sites, the Barrio Family Health Center in Southeast San Antonio, TX and the Dr. Frank Bryant
Health Center also in San Antonio. CommuniCare serves approximately 45,000 subjects a year
of which it is estimated that 5000 are requiring diabetic care. Project ECHO in conjunction
with the University of New Mexico collaborates with over 20 rural clinics in New Mexico to
provide service to underserved areas in New Mexico. A recruitment flyer and consent forms
will be provided to each site. Clinic staff will recruit subject for the study during
scheduled visits. Subject will be given a flyer containing information about the study and
the informed consent document. Subjects who are interested in being enrolled in the study
will be referred to a photographer within the site for Retinal imaging. Subjects will not
receive a payment or stipend for participation in this study.
There are no screening requirements for subjects to participate in this trial. Subjects must
be diagnosed as a person with pre-diabetes or diabetes by a medical professional. There is
no requirement or solicitation for information regarding prior or concomitant therapy. There
are no criteria set forth for subjects to exit or be discontinued from the study once the
retinal screening is performed. Subjects will not be withdrawn from the study once retinal
screening has occurred. Once the subject completes retinal screening, the period of subject
participation is concluded. Images taken from subjects may not be used in the study due to
inadequate image quality. The number of images found to be inadequate will be tracked and
reported at the completion of the study. Retinal screening marks both the beginning and the
end of subject participation in this study.
For each eye, a minimum of two posterior pole images will be collected. One image will be
centered on the fovea and the second on the optic disc. A third image will be collected of
the anterior segment (front of the eye). Subjects will not be pharmacologically dilated.
Imaging will rely on natural dilation due to adaptation to darkness in the imaging room.
More than two images per eye will be collected only when the imager (photographer)
identifies any given image of insufficient quality for reading. Poor quality images are
typically due to physiological reasons, such as blinking or small pupils and will not be
used as part of this study. The retinal photographer will attempt up to 3 times to acquire
images of a subject's eyes in order to complete the imaging protocol. The study coordinator
will conduct weekly audits of the imaging procedure in order to ensure and document
compliance with the study protocol.
The Class II Medical Device that will be used for this study will be a non mydriatic or
equivalent retinal camera. The retinal camera is intended to be used for taking digital
images of the retina of the human eye without the use of pharmacological dilation. The
retinal camera has the following photography modes: RGB color. A Digital Camera is mounted
to the retinal camera to perform retinal imaging.
A picture archival and communication system (PACS) is used to receive DICOM images,
scheduling information and textual reports, organize and store them in an internal format,
and to make that information available across a network via HIPAA and FDA-cleared secure
user interfaces. The PACS is comprised of a capture component, a central server component,
and a viewer component that is used on general purpose computing hardware. Subject
information, procedure information, and image acquisition data is captured, sent to a server
or alternatively, it is accepted directly from a DICOM compliant device. After receiving
image objects and associated data, the server registers the incoming data and images with
the archive including any associations with prior cases. The cases are presented to users
with the correct permissions from a work list as controlled by a managing user. The image
data is transmitted and rendered on the user's workstation using a standard web browser.
Once the server registers a report, the report is available to the referring physician or
client service electronically or via fax.
Immediately after the images and Subject demographics are collected, the photographer will
upload the data as a case to the PACS via a VPN connection established between the imaging
workstation and PACS. If the VPN connection cannot be established at the time of imaging,
the upload will be done at a later time, e.g. end of the clinic day. The data will reside in
the imaging workstation for up to five days in order to assure upload. The clinical
coordinator will conduct weekly audits of upload completion. Once in PACS, cases are read by
readers using a built in reading template that generates a report with their findings. The
study will not disrupt standard of care to the study subjects. Each site will follow its own
standard procedures and care. Findings will be reported to the clinic which referred the
subject for screening. Clinics will be responsible for follow-up care including any
necessary intervention or therapy.
Performance of the RiskAnalyzer: The performance of the RiskAnalyzer will be calculated by
applying the minimally acceptable values for sensitivity (Seo) and specificity (Spo) values
specified in advance. For purposes of this study, the specified null hypotheses values are
Seo=0.85 and Spo=0.70. These values are based on data obtained from ophthalmic exams. The
efficacy of trained readers using retinal photography has been demonstrated to provide the
most sensitive screening and monitoring test for sight-threatening retinopathy, with
sensitivities > 80%. Abramoff, et al. discuss the limits of sensitivity that can be achieved
by any system given the fallibility of ground truth based on multiple human readers. He
suggests that 0.85 is the limit of sensitivity that one can achieve. The specificity is
based on the efficiency that we seek in order to make this implementation commercially
viable. We have designed our study to achieve 0.90 statistical power and 0.99 significance
level. If confidence limits are based on asymptotic normal distribution theory, then sample
sizes can be based on the asymptotic variance formulae, as given by Pepe.
Objective One: Objective one is to test fully the study data flow logistics and information
transfer interfaces. The testing will be done entirely at one recruitment, enrollment and
imaging site. The duration of time to complete this objective is three months.
Materials and Research Design for Objective One: Subjects will be recruited from single
site. All images will be routed to two readers for grading. If the two readers assign
equivalent grades to the image, a generated report will be given to the clinic to distribute
the referring physician. For cases in which the readers assign different grades for the same
image, the image will be routed to an adjudicator for resolution. The adjudicator will have
access to the reports generated by each reader, but not the risk levels from the
RiskAnalyzer. A report from the adjudicator will be generated and reported to the clinic
that will be responsible for distributing the report to the Subject and for any further
follow-up. Images will also be de-identified and routed to the RiskAnalyzer. The
RiskAnalyzer will perform its analysis of the image and generate a risk stratification of
either "Low risk" or "High risk" for diabetic retinopathy. A report containing the risk
levels assigned by the RiskAnalyzer will not be distributed to the referring physician,
clinic or adjudicator but used only for statistical analysis in support of the endpoints of
the trial.
Outcomes for Objective One: Data outcomes will demonstrate the ability to recruit and enroll
subject into the study at a single site, perform retinal imaging, upload the images to a
PACS, have the same images graded by two different readers, when necessary routed and graded
by an adjudicator and the ability to generate a final report. The reading process followed
by the readers is based on the International Clinical Diabetic Retinopathy Disease Severity
Scale. Additionally data will demonstrate that images are successfully routed to the
RiskAnalyzer for processing.
Objective Two: Objective two is to evaluate the efficacy of the RiskAnalyzer to identify the
risk of Diabetic Retinopathy in comparison to the gold standard. The duration of time to
complete this objective is nine months.
Methods and Research Design for Objective Two: Subjects are recruited from multiple
CommuniCare and Project ECHO sites. All images are graded by two readers and an adjudicator
should the grading by the first and second reader not be in agreement. The reading process
followed by the readers is based on the International Clinical Diabetic Retinopathy Disease
Severity Scale. A consensus report generated by the readers or the adjudicator indicating
presence and severity of diabetic retinopathy will be given to the Subject through their
referring physician and referred to a specialist if necessary by the referring physician.
The same images graded by the readers will also be routed to the RiskAnalyzer for processing
which will generate a risk level of either "Low risk" or "High risk" for diabetic
retinopathy. As the images are routed to the RiskAnalyzer, the images will be de-identified
and sequestered until evaluated by the RiskAnalyzer. Risk levels obtained by use of the
RiskAnalyzer will not be given to the Subject under any circumstances. The referring
physician is also masked from the risk levels assigned by the RiskAnalyzer. Referring
physicians are not co-located at VisionQuest Biomedical and therefore will not have any
access to the computers or data storage area for the data.
Outcomes for Objective Two: Statistical analysis will indicate the accuracy level of the
RiskAnalyzer as compared to the gold standard. Statistical analysis will use sensitivity,
specificity, AUC, and a level of agreement using Cohen's kappa coefficients.
Objective Three: Objective three will address the primary endpoint of the trial which is to
demonstrate that the reader's accuracy in grading images is enhanced when risk levels from
the algorithm are made available to the reader while performing the grading of the images.
The duration of time to complete this objective is 12 months.
Methods and Research Design for Objective Three: The RiskAnalyzer will be used as a first
reader. There will continue to be two human readers and an adjudicator. Ground Truth will be
established by either the agreement of reader one with reader two or by an adjudicator. All
images will be routed to the RiskAnalyzer which will generate a risk level of either "Low
risk" or "High risk" for diabetic retinopathy. The cases will be divided into two sets and
routed to both readers. One set of images will be routed to both readers with the algorithm
assigned risk levels while the other set of images will be routed to both readers without
the algorithm assigned risk level. An equivalent number of 'Low risk" and "High risk" cases
will be selected for each set of images. Ground Truth is established by the two readers
assigning the same grade to the same image. When different grades are assigned to the same
image by two different readers, the cases will be routed to an adjudicator for grading and
reporting. The adjudication will become ground truth. The cases that will be adjudicated
will only be those that are different categories of risk stages. Adjudication will be based
on the clinical significance of the disagreement between the readers as follows: cases
within severity scales 0 and 1 will be classified as "Low Risk" cases, while cases within
the severity scales 2 and above will be classified as "High Risk" cases. Cases needing
adjudication will be those differing in risk and those within the High Risk Category that
differ between scales 2 and 3 (mild and severe), and 2 and 4 (mild and proliferative
Diabetic Retinopathy -PDR).
Outcomes for Objective Three: The outcomes from objective three will establish that the
RiskAnalyzer improves the reading accuracy and consistency between readers and decreases
bias between human readers. Statistical Analysis of level of agreement will be performed on
the risk assigned to the images by the readers when having and not having the risk levels
assigned by the algorithm using Cohen's kappa coefficients.
Expected outcomes: Telemedicine retinal screening in conjunction with risk levels from the
RiskAnalyzer improve the accuracy of readers when grading images. The use of risk levels
assigned by the RiskAnalyzer in assisting the readers will decrease the amount of time
readers dedicate to the grading of each case. This may be a model to support the increase of
access to retinal screening, support compliance with retinal screening recommendations and
facilitate a more efficient use of the retinal specialist to evaluate and treat disease
leading to a more cost efficient method of care.
photographs with and without the assistance of the RiskAnalyzer
Sensitivity and specificity of retinal screening for risk stratification of DR using digital
fundus photographs and the RiskAnalyzer
Clinical Trial Methods and Research Design: A total of 10,000 subjects will be recruited to
participate in this study. These subjects will be enrolled through two parallel
collaborators, Extension for Community Healthcare Outcomes (Project ECHO) and CommuniCare
Health Centers. Each clinic will obtain approximately 50% of the cases per year or an
average of 50 cases per week. Subjects will be identified from clinics, CommuniCare Health
Centers of San Antonio, TX and Project ECHO, New Mexico. CommuniCare has two associated
sites, the Barrio Family Health Center in Southeast San Antonio, TX and the Dr. Frank Bryant
Health Center also in San Antonio. CommuniCare serves approximately 45,000 subjects a year
of which it is estimated that 5000 are requiring diabetic care. Project ECHO in conjunction
with the University of New Mexico collaborates with over 20 rural clinics in New Mexico to
provide service to underserved areas in New Mexico. A recruitment flyer and consent forms
will be provided to each site. Clinic staff will recruit subject for the study during
scheduled visits. Subject will be given a flyer containing information about the study and
the informed consent document. Subjects who are interested in being enrolled in the study
will be referred to a photographer within the site for Retinal imaging. Subjects will not
receive a payment or stipend for participation in this study.
There are no screening requirements for subjects to participate in this trial. Subjects must
be diagnosed as a person with pre-diabetes or diabetes by a medical professional. There is
no requirement or solicitation for information regarding prior or concomitant therapy. There
are no criteria set forth for subjects to exit or be discontinued from the study once the
retinal screening is performed. Subjects will not be withdrawn from the study once retinal
screening has occurred. Once the subject completes retinal screening, the period of subject
participation is concluded. Images taken from subjects may not be used in the study due to
inadequate image quality. The number of images found to be inadequate will be tracked and
reported at the completion of the study. Retinal screening marks both the beginning and the
end of subject participation in this study.
For each eye, a minimum of two posterior pole images will be collected. One image will be
centered on the fovea and the second on the optic disc. A third image will be collected of
the anterior segment (front of the eye). Subjects will not be pharmacologically dilated.
Imaging will rely on natural dilation due to adaptation to darkness in the imaging room.
More than two images per eye will be collected only when the imager (photographer)
identifies any given image of insufficient quality for reading. Poor quality images are
typically due to physiological reasons, such as blinking or small pupils and will not be
used as part of this study. The retinal photographer will attempt up to 3 times to acquire
images of a subject's eyes in order to complete the imaging protocol. The study coordinator
will conduct weekly audits of the imaging procedure in order to ensure and document
compliance with the study protocol.
The Class II Medical Device that will be used for this study will be a non mydriatic or
equivalent retinal camera. The retinal camera is intended to be used for taking digital
images of the retina of the human eye without the use of pharmacological dilation. The
retinal camera has the following photography modes: RGB color. A Digital Camera is mounted
to the retinal camera to perform retinal imaging.
A picture archival and communication system (PACS) is used to receive DICOM images,
scheduling information and textual reports, organize and store them in an internal format,
and to make that information available across a network via HIPAA and FDA-cleared secure
user interfaces. The PACS is comprised of a capture component, a central server component,
and a viewer component that is used on general purpose computing hardware. Subject
information, procedure information, and image acquisition data is captured, sent to a server
or alternatively, it is accepted directly from a DICOM compliant device. After receiving
image objects and associated data, the server registers the incoming data and images with
the archive including any associations with prior cases. The cases are presented to users
with the correct permissions from a work list as controlled by a managing user. The image
data is transmitted and rendered on the user's workstation using a standard web browser.
Once the server registers a report, the report is available to the referring physician or
client service electronically or via fax.
Immediately after the images and Subject demographics are collected, the photographer will
upload the data as a case to the PACS via a VPN connection established between the imaging
workstation and PACS. If the VPN connection cannot be established at the time of imaging,
the upload will be done at a later time, e.g. end of the clinic day. The data will reside in
the imaging workstation for up to five days in order to assure upload. The clinical
coordinator will conduct weekly audits of upload completion. Once in PACS, cases are read by
readers using a built in reading template that generates a report with their findings. The
study will not disrupt standard of care to the study subjects. Each site will follow its own
standard procedures and care. Findings will be reported to the clinic which referred the
subject for screening. Clinics will be responsible for follow-up care including any
necessary intervention or therapy.
Performance of the RiskAnalyzer: The performance of the RiskAnalyzer will be calculated by
applying the minimally acceptable values for sensitivity (Seo) and specificity (Spo) values
specified in advance. For purposes of this study, the specified null hypotheses values are
Seo=0.85 and Spo=0.70. These values are based on data obtained from ophthalmic exams. The
efficacy of trained readers using retinal photography has been demonstrated to provide the
most sensitive screening and monitoring test for sight-threatening retinopathy, with
sensitivities > 80%. Abramoff, et al. discuss the limits of sensitivity that can be achieved
by any system given the fallibility of ground truth based on multiple human readers. He
suggests that 0.85 is the limit of sensitivity that one can achieve. The specificity is
based on the efficiency that we seek in order to make this implementation commercially
viable. We have designed our study to achieve 0.90 statistical power and 0.99 significance
level. If confidence limits are based on asymptotic normal distribution theory, then sample
sizes can be based on the asymptotic variance formulae, as given by Pepe.
Objective One: Objective one is to test fully the study data flow logistics and information
transfer interfaces. The testing will be done entirely at one recruitment, enrollment and
imaging site. The duration of time to complete this objective is three months.
Materials and Research Design for Objective One: Subjects will be recruited from single
site. All images will be routed to two readers for grading. If the two readers assign
equivalent grades to the image, a generated report will be given to the clinic to distribute
the referring physician. For cases in which the readers assign different grades for the same
image, the image will be routed to an adjudicator for resolution. The adjudicator will have
access to the reports generated by each reader, but not the risk levels from the
RiskAnalyzer. A report from the adjudicator will be generated and reported to the clinic
that will be responsible for distributing the report to the Subject and for any further
follow-up. Images will also be de-identified and routed to the RiskAnalyzer. The
RiskAnalyzer will perform its analysis of the image and generate a risk stratification of
either "Low risk" or "High risk" for diabetic retinopathy. A report containing the risk
levels assigned by the RiskAnalyzer will not be distributed to the referring physician,
clinic or adjudicator but used only for statistical analysis in support of the endpoints of
the trial.
Outcomes for Objective One: Data outcomes will demonstrate the ability to recruit and enroll
subject into the study at a single site, perform retinal imaging, upload the images to a
PACS, have the same images graded by two different readers, when necessary routed and graded
by an adjudicator and the ability to generate a final report. The reading process followed
by the readers is based on the International Clinical Diabetic Retinopathy Disease Severity
Scale. Additionally data will demonstrate that images are successfully routed to the
RiskAnalyzer for processing.
Objective Two: Objective two is to evaluate the efficacy of the RiskAnalyzer to identify the
risk of Diabetic Retinopathy in comparison to the gold standard. The duration of time to
complete this objective is nine months.
Methods and Research Design for Objective Two: Subjects are recruited from multiple
CommuniCare and Project ECHO sites. All images are graded by two readers and an adjudicator
should the grading by the first and second reader not be in agreement. The reading process
followed by the readers is based on the International Clinical Diabetic Retinopathy Disease
Severity Scale. A consensus report generated by the readers or the adjudicator indicating
presence and severity of diabetic retinopathy will be given to the Subject through their
referring physician and referred to a specialist if necessary by the referring physician.
The same images graded by the readers will also be routed to the RiskAnalyzer for processing
which will generate a risk level of either "Low risk" or "High risk" for diabetic
retinopathy. As the images are routed to the RiskAnalyzer, the images will be de-identified
and sequestered until evaluated by the RiskAnalyzer. Risk levels obtained by use of the
RiskAnalyzer will not be given to the Subject under any circumstances. The referring
physician is also masked from the risk levels assigned by the RiskAnalyzer. Referring
physicians are not co-located at VisionQuest Biomedical and therefore will not have any
access to the computers or data storage area for the data.
Outcomes for Objective Two: Statistical analysis will indicate the accuracy level of the
RiskAnalyzer as compared to the gold standard. Statistical analysis will use sensitivity,
specificity, AUC, and a level of agreement using Cohen's kappa coefficients.
Objective Three: Objective three will address the primary endpoint of the trial which is to
demonstrate that the reader's accuracy in grading images is enhanced when risk levels from
the algorithm are made available to the reader while performing the grading of the images.
The duration of time to complete this objective is 12 months.
Methods and Research Design for Objective Three: The RiskAnalyzer will be used as a first
reader. There will continue to be two human readers and an adjudicator. Ground Truth will be
established by either the agreement of reader one with reader two or by an adjudicator. All
images will be routed to the RiskAnalyzer which will generate a risk level of either "Low
risk" or "High risk" for diabetic retinopathy. The cases will be divided into two sets and
routed to both readers. One set of images will be routed to both readers with the algorithm
assigned risk levels while the other set of images will be routed to both readers without
the algorithm assigned risk level. An equivalent number of 'Low risk" and "High risk" cases
will be selected for each set of images. Ground Truth is established by the two readers
assigning the same grade to the same image. When different grades are assigned to the same
image by two different readers, the cases will be routed to an adjudicator for grading and
reporting. The adjudication will become ground truth. The cases that will be adjudicated
will only be those that are different categories of risk stages. Adjudication will be based
on the clinical significance of the disagreement between the readers as follows: cases
within severity scales 0 and 1 will be classified as "Low Risk" cases, while cases within
the severity scales 2 and above will be classified as "High Risk" cases. Cases needing
adjudication will be those differing in risk and those within the High Risk Category that
differ between scales 2 and 3 (mild and severe), and 2 and 4 (mild and proliferative
Diabetic Retinopathy -PDR).
Outcomes for Objective Three: The outcomes from objective three will establish that the
RiskAnalyzer improves the reading accuracy and consistency between readers and decreases
bias between human readers. Statistical Analysis of level of agreement will be performed on
the risk assigned to the images by the readers when having and not having the risk levels
assigned by the algorithm using Cohen's kappa coefficients.
Expected outcomes: Telemedicine retinal screening in conjunction with risk levels from the
RiskAnalyzer improve the accuracy of readers when grading images. The use of risk levels
assigned by the RiskAnalyzer in assisting the readers will decrease the amount of time
readers dedicate to the grading of each case. This may be a model to support the increase of
access to retinal screening, support compliance with retinal screening recommendations and
facilitate a more efficient use of the retinal specialist to evaluate and treat disease
leading to a more cost efficient method of care.
Inclusion Criteria:
- Patients over the age of 18
- Patients diagnosed as with either PreDiabetes or Diabetes type 1 or type 2
Exclusion Criteria:
- People not diagnosed with either PreDiabetes or Diabetes type 1 or type 2
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