The study will be carried out in two stages. Individuals
attending the comprehensive ophthalmology clinic who meet inclusion criteria
will be asked to participate in the study. The Patient Information Sheet will
be provided to them, and after review and discussion, written informed consent
will be obtained from those willing to participate in the study. Basic
demographic details including age and gender will be obtained from the
participants after they undergo refraction and intraocular pressure evaluation
by non-contact tonometry.
Stage 1: Patients will undergo testing with the AI-based fundus camera device before
their comprehensive ophthalmology visit. The research investigator will
initially attempt to capture the optic nerve head image without dilating the patient,
completing a maximum of two attempts to achieve an image of sufficient quality
for AI evaluation. It is estimated that up to 40% of patients will require
dilation for the device to obtain an adequate, gradable image that allows the Medios
AI to assess for glaucoma. If a patient requires dilation, the patient will
first be seen by the ophthalmologist who will determine if dilation is safe.
After dilation, an additional two attempts will be made to obtain an image of
sufficient quality to be graded for glaucoma. If the device is unable to obtain
a gradable image following dilation, the patient will be noted to be ungradable
by AI and continue with their routine evaluation. The total time taken to
obtain the images will be noted down in the proforma.
Testing with the AI-based fundus camera device offers four
possible outcomes:
·
Referable
Glaucoma (RG) – The patient requires referral to a glaucoma clinic
·
Disc
Suspect (DS)- suggested referral to a glaucoma clinic
·
No
Referable Glaucoma (NRG)
·
Ungradable
For the purposes of our study, both the RG and DS
groups will be considered to have “referable glaucoma,†while the NRG group
will be maintained as the “no referable glaucoma†group.
The patient will complete their comprehensive
ophthalmology clinic visit after imaging with the camera. The results of the
device assessment will be masked, as neither the patient nor the comprehensive
ophthalmologist will be informed of the results of the AI-based fundus camera
device assessment before or after the clinic visit. Comprehensive
ophthalmologists are defined as physicians with at least 3 years of experience
after completing ophthalmology residency. All comprehensive ophthalmologists involved
in the study currently provide care to patients who visit Aravind Eye Hospital
in Pondicherry, India.
The comprehensive ophthalmologists will follow normal
clinic workflow, completing a formal referral to glaucoma clinic if a patient
is considered to have “referable glaucoma.†In terms of normal clinic workflow,
the comprehensive ophthalmologists will complete a determination for potential glaucoma
clinic referral based on the patient’s optic disc appearance, slit lamp exam
findings, intraocular pressure(s), a potential gonioscopy and assessment for
shallow chambers, family history, and any other eye exam findings or testing
they deem relevant. They will be required to document the specific reason(s)
for the referral.
By the end of this stage, participants with “referable
glaucoma†will be those referred by:
·
The
AI-based fundus camera device only.
·
Both
AI-based fundus camera device and the comprehensive ophthalmologist.
·
The
comprehensive ophthalmologist only.
These participants will continue with the testing
described in Stage 2 below.
The remainder of patients will have been determined to
have “no referable glaucoma†by both the device and the ophthalmologist. Most
of these remaining participants will not undergo any further testing in Stage 2;
their involvement in the study will be complete and they will be provided
standard of care as per their ocular diagnosis by the comprehensive
ophthalmologist. However, for the purposes of specificity testing, a cohort of 60
patients in the “no referable glaucoma†group will be requested to complete the
additional tests detailed in Stage 2 below. These patients will be randomly
selected as follows: the 10th patient considered to have “no referable
glaucoma†will be requested to partake in Stage 2 testing, followed by n+10
until we reach 60 subjects. If a patient refuses, we will defer to the
following normal patient (n+11) as necessary.
Stage 2: Those with “referable glaucoma,†as well as about 60 patients from the
“no referable glaucoma†group, will have a 24-2 Humphrey Field Analyzer (HFA,
Model 860 HFA 3; Carl Zeiss Meditec Inc, USA) and an image taking of the optic nerve and retinal
nerve fiber layer using optical coherence tomography (Model
5000, Cirrus HD-OCT; Carl Zeiss Meditec Inc, USA). They will also be examined by a glaucoma specialist.
If the participant cannot stay for testing after their comprehensive
ophthalmology clinic visit, the research team will try to schedule a follow-up
date for them to complete the HFA and OCT testing.
The final component of Stage 2 will rely on
asynchronous assessments of all "referable glaucoma†participants by a
minimum of two glaucoma specialists. Firstly, the first glaucoma specialist will
render an initial assessment and diagnosis. This specialist will use all
available participant data, HFA, OCT, comprehensive ophthalmology clinic evaluation
notes, and relevant patient history from chart review. The specialist will be
masked to the results of the Remidio AI as well as the clinical evaluation and findings of comprehensive
ophthalmologists. The final diagnosis provided by this specialist will fall
into one of the following categories:
·
Definite
glaucoma
·
Probable
glaucoma (>75% chance of glaucoma)
·
Possible
glaucoma (10-75% chance of glaucoma)
·
No
glaucoma (<10 % chance of glaucoma)
Following this initial diagnosis, a second glaucoma
specialist will complete the same assessment and diagnosis process as the first
specialist with all the available data for each participant. However, he/she will
be masked to the determination of the first specialist. Should the second
specialist agree with the initial specialist’s diagnosis, the diagnosis will be
final. However, should the second specialist disagree with the initial
specialist’s categorization, a third glaucoma specialist will adjudicate in
this circumstance to make the final diagnosis.
There will likely be a substantial subset of patients
with unreliable HFA and/or OCT testing results due to various reasons including
cataracts. In such cases, rather than excluding these patients or completing additional
attempts to obtain a reliable test result, the glaucoma specialists will have
to incorporate any unreliable testing results into their final glaucoma risk
assessment evaluations. |