Early Detection of Glaucoma with Objective Pupil Testing

There is obviously some value to this device but the cost seems a bit high for a pretesting device. I couldn't justify the cost when my Optovue has a screener function that can be done in seconds and is more specific for glaucoma.
I think this is why this device might not sell well. First, the Optovue does more than screening so it's not a fair comparison.

Screening in the Optovue is a side benefit. But optometrists in general will not pay for anything that they feel they can do cheaper.

I think this device is probably great but Konan has another device that falls under a similar category, their ColorDx which they are trying to bundle with this device. Most ODs would rather stick to a penlight and the Ishihara.

But I think the EyeKinetix is more sensitive so is worth a look.
 
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Just a few more points, and then I'm done!

1. Pupillary testing is often not done at all, because docs start out looking hard, never find anything, and give up looking.
(In med school I remember doing the swinging flashlight on rounds in 10 seconds flat and writing "PERRL" more times than I can count -- but unless the patient had a grossly blown pupil, I'm certain I missed some asymmetry.)

2. If adding technology that can be delegated to a tech (ie, take up less of the doctor's time), results in pupils being checked routinely, accurately, quickly and objectively, how can that be a bad thing?

I get in your case Lloyd you're at a university, you want to show students how to do everything manually (and your caseload is probably such that you don't see 40+ patients a day every day).

But in the world outside of academia, consider that most docs don't do a thorough job checking the pupils (if they do it at all). Heck, in one of the cases LCT reviews, the patient was under the care of a board-certified neurologist who MISSED the RAPD -- despite probably doing dozens swinging flashlights every day for years.

3. The natural variability in pupil responses doesn’t change with EyeKinetix or the swinging flashlight test. Therefore, assuming you are very good at the flashlight test, and use ND filters, you are just as likely to have a false positive or false negative with either method.
Funny Adam..I was in a malpractice case I which a walk=in clinic doc stained an eye with Flourscein (didn't know a contact was in the eye) .

Used a woods lamp and missed a central ulcer because the contact lit up and hid everything behind it. He recorded PERRLA and the eye is red and RX Tobradex TID for mucopurulent conjunctivitis.

I had the attorney I was working ask him what PERRLA meant and he said the pupils reacted to light. when he pressed hin to what the acronym meant he didn't know..

Case was won on other basis but it shows how used to abbreviations we have and use
 
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Funny Adam..I was in a malpractice case I which a walk=in clinic doc stained an eye with Flourscein (didn't know a contact was in the eye) . Used a woods lamp and missed a central ulcer because the contact lit up and hid everything behind it. He recorded PERRLA and the eye is red and RX Tobradex TID for mucopurulent conjunctivitis. I had the attorney I was working ask him what PERRLA meant and he said the pupils reacted to light. when he pressed hin to what the acronym meant he didn't know..Case was won on other basis but it shows how used to abbreviations we have and use

holy moly, tell me you're not being serious.... Did the attorneys audibly gasp?!
 
I think this is why this device might not sell well. First, the Optovue does more than screening so it's not a fair comparison. Screening in the Optovue is a side benefit. But optometrists in general will not pay for anything that they feel they can do cheaper. I think this device is probably great but Konan has another device that falls under a similar category, their ColorDx which they are trying to bundle with this device. Most ODs would rather stick to a penlight and the Ishihara. But I think the EyeKinetix is more sensitive so is worth a look.

My point being that this device might not be all that necessary or worth the price for those of us that already have an OCT with a screening function.
 
My point being that this device might not be all that necessary or worth the price for those of us that already have an OCT with a screening function.
I agree with you on both points. The thing is though you cannot not do pupils for a comprehensive exam. You might as well do it the best you can. But IMO I think it's a tough sell at $6k let alone $12k.
 
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I agree with you on both points. The thing is though you cannot not do pupils for a comprehensive exam. You might as well do it the best you can. But IMO I think it's a tough sell at $6k let alone $12k.

Mike Ware OD said: arrow_drop_up
My point being that this device might not be all that necessary or worth the price for those of us that already have an OCT with a screening function.


Did both of you come to your conclusion after viewing the Webinar?

I spent the hour viewing and actually stayed awake.;) My impression was quite different.

A great additional diagnostic tool in addition to what the speaker already has. Itt can be performed with great accuracy in a few minutes by a technician. The added information allows for differential diagnosis.

Best of all, the 10K cost is pin money for a busy practice which allows an OD to have the edge in treating patients.

Please spend the time viewing the Webinar and then come to conclusions.
 
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Did both of you come to your conclusion after viewing the Webinar?

I spent the hour viewing and actually stayed awake.;) My impression was quite different.

A great additional diagnostic tool in addition to what the speaker already has. Itt can be performed with great accuracy in a few minutes by a technician. The added information allows for differential diagnosis.

Best of all, the 10K cost is pin money for a busy practice which allows an OD to have the edge in treating patients.

Please spend the time viewing the Webinar and then come to conclusions.
One thing many practices do is create "enhanced pre-testing". The most common nowadays is Wide-field imaging such as Optos for anywhere from $20-$40. I can see making it $35-$50" and include this, digital color vision, wide-field imaging Konan cell count screening etc. No, not all patients will say yes but a 5-year lease for a 10K piece of equipment would be paid if 2 people per day do it in a 1 doc practice. (That doesn't count the benefit of the tax savings of a 179 election as well as the wow factor in practice building as well as the increased revenue for additional testing when problems are detected.)

At some point also the lease will be paid and the profits increased as well as the level of patient care!

There are some offices that will never take the leap forward and they will be left behind with this and many more technologies.
 
Did both of you come to your conclusion after viewing the Webinar?

I spent the hour viewing and actually stayed awake.;) My impression was quite different.

A great additional diagnostic tool in addition to what the speaker already has. Itt can be performed with great accuracy in a few minutes by a technician. The added information allows for differential diagnosis.

Best of all, the 10K cost is pin money for a busy practice which allows an OD to have the edge in treating patients.

Please spend the time viewing the Webinar and then come to conclusions.
Pupil response is too nonspecific to diagnose glaucoma. It does not help in your differential diagnosis.
 
Pupil response is too nonspecific to diagnose glaucoma. It does not help in your differential diagnosis.
Agreed Lloyd, but in the absence of high IOP and normal looking optic nerve what else can be used in the general Optometric examination to pick up asymmetric optic nerve function potentially?
 
Pupil response is too nonspecific to diagnose glaucoma. It does not help in your differential diagnosis.
This is not true (see attached, from 2015 and 2016, from the academy of ophthalmology) ...
 

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Colleagues, as a member of ODWire for more than a dozen years (the picture to the left is clear evidence of the passage of time), I have intermittently enjoyed lurking through the discourse on a host of topics. Having listened to Craig's talk and with intimate involvement in the development of the discussed pupillometer project and its predecessor (as well as our pupil-sensed objective perimeter project), I thought that I could add a unique perspective to this particular discussion. I generally have thought that it is not appropriate to comment, but with this there are some clear gaps that can be filled.

Pupillary responses are a non-linear system that are driven strongly by light reflexes but with inputs from other intrinsic, extrinsic, and visceral sources. Historically, clinicians have noted when they subjectively perceive an asymmetry between the responses of the two eyes, a positive Marcus Gunn sign.

A higher level of subjective assessment is to quantify any asymmetry by attenuating the light dosage to the higher responding eye with neutral density filters, typically with a staged filter bar in 0.3 log steps (0.3 to 1.8 ND) until the asymmetry is no longer perceptible. The log-steps of 0.3 ND are generally quite a coarse measure (think of a yard stick with marks only at each ½ foot) and values subjectively assessed are “binned” (positively or negatively) into these relatively large steps. This has been, however, the best that could be done.

Researchers have described clearly normal variability in the PLR (pupillary light reflex)[1]. This is not new, it just isn't apparent with how it has been measured typically, clinically unless you were a researcher. The response itself varies in small amounts from moment to moment regardless of how the PLR is assessed, as do other dynamic biological systems such as blood pressure, IOP, and heartrate. Some variability of non-linear biological measures is not a reason to not measure it at all, but thoughtful professional understanding of the nature and meaning should be taken into account when assessing the importance of the measures. A snapshot of the response at a moment in time is important, can be delegated, and even repeated serially just as is often done with sphygmomanometry for the same practical reasons.

The machine-vision system sees:
  • pupil sizes measured to sub-pixel precision;
  • clearly the distinct pupil border between a dark iris and a black pupil in a dark environment under infrared imaging;
  • clear differentiation between pupil response asymmetry and base-line pupil size asymmetry of anisocoria; and
  • both the direct and consensual responses simultaneously,
all of which human, subjective assessments typically cannot do.

The responses video can also be played back for further assessment by the physician. The machine vision system reports in high-detail the response that is elicited and, with a test’s short series of paired responses, biological noise not attributed to the machine-administered light stimuli, is generally well-minimized from averaging.

In regard to quantification, researchers have described that a 0.3 ND asymmetry[2] could be a marker as to when the functional asymmetry may start becoming interesting or relevant, as a red flag, to potentially look deeper as to why asymmetry is present. It may be helpful to recall, in practical terms, that a 0.3 ND filter absorbs 50% of the light, a 0.6 ND -> 75%, and 0.9 ND -> 85%. With an asymmetry in which one eye’s response corresponds to a 50% reduction of light, or more, compared to the response of the fellow higher responsive eye, it feels obvious that we would want to look closer as to the nature of this marked functional difference. It will feel both surprising and logical as to how there is a spectrum of asymmetry in the patients you see each day and periodically it will be dramatic triggering some introspection as to what has passed through your office prior.

Other key aspects:
  • Glaucoma is a common condition that may cause an APD, but not all glaucoma will present asymmetrically, and as the depth of the disease increases, asymmetry decreases as total retinal function becomes significantly depressed.
  • There are many other causes of asymmetry, and may even include amblyopia that is commonly not considered. I have personal experience with this.
  • Pupil testing is not defined as an optional test for a comprehensive exam either by the AOA or AAO, but it is clear from hundreds of discussions that collection of this important physical sign is often ignored (some docs become salty in the importance of this testing after not finding very much over time), delegated with embarrassingly poor quality control, or routinely assessed with sub-optimum results. Notations of administration in patient’s record when it has been done poorly by techs or not at all can be problematic on multiple levels.
  • A machine-vision assessment can be easily administered by a technician with results that can be reviewed by the doc even after dilation. It is a tool to help you discover physical signs that routinely are missed.
  • The PLR is difficult to perform well, naturally has variability, and this can now be well measured objectively. A machine vision assessment of PLR is of course not a requirement nor are OCTs, autorefractors, fundus cameras or other technology-augmented tools, but it is uncomfortable practicing without them.
If you are very comfortable with the precision and simplicity of the APD testing you are doing and you are are regularly uncovering the asymmetry we are tasked with uncovering, great! If a technician-adminstered test that is likely much more detailed that what you can do yourself could be of value in your practice, there are interesting solutions now. You will be surprised at what you have been missing.

Best regards,
Charles Wm. Stewart, OD
CEO, Konan Medical USA, Inc.

__________
1. Satou, Tsukasa, et al. "Evaluation of relative afferent pupillary defect using RAPDx device in patients with optic nerve disease." Neuro-Ophthalmology 40.3 (2016): 120-124.

2. Tatham, A.J., Meira-Freitas, D., Weinreb, R.N., Marvasti, A.H., Zangwill, L.M. and Medeiros, F.A., 2014. Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect. Investigative ophthalmology & visual science, 55(1), pp.513-522.
 
This is not true (see attached, from 2015 and 2016, from the academy of ophthalmology) ...
Both of those are PPPs. They have nothing supporting the pupil response being specific to glaucoma. It is not. I see APDs all the time from neuro etiologies. I have one from my TBI.

I talked to my OD, PhD friend today who specializes in the pupil response. She agrees that is is too nonspecific to diagnose a disease with.
 
Colleagues, as a member of ODWire for more than a dozen years (the picture to the left is clear evidence of the passage of time), I have intermittently enjoyed lurking through the discourse on a host of topics. Having listened to Craig's talk and with intimate involvement in the development of the discussed pupillometer project and its predecessor (as well as our pupil-sensed objective perimeter project), I thought that I could add a unique perspective to this particular discussion. I generally have thought that it is not appropriate to comment, but with this there are some clear gaps that can be filled.

Pupillary responses are a non-linear system that are driven strongly by light reflexes but with inputs from other intrinsic, extrinsic, and visceral sources. Historically, clinicians have noted when they subjectively perceive an asymmetry between the responses of the two eyes, a positive Marcus Gunn sign.

A higher level of subjective assessment is to quantify any asymmetry by attenuating the light dosage to the higher responding eye with neutral density filters, typically with a staged filter bar in 0.3 log steps (0.3 to 1.8 ND) until the asymmetry is no longer perceptible. The log-steps of 0.3 ND are generally quite a coarse measure (think of a yard stick with marks only at each ½ foot) and values subjectively assessed are “binned” (positively or negatively) into these relatively large steps. This has been, however, the best that could be done.

Researchers have described clearly normal variability in the PLR (pupillary light reflex)[1]. This is not new, it just isn't apparent with how it has been measured typically, clinically unless you were a researcher. The response itself varies in small amounts from moment to moment regardless of how the PLR is assessed, as do other dynamic biological systems such as blood pressure, IOP, and heartrate. Some variability of non-linear biological measures is not a reason to not measure it at all, but thoughtful professional understanding of the nature and meaning should be taken into account when assessing the importance of the measures. A snapshot of the response at a moment in time is important, can be delegated, and even repeated serially just as is often done with sphygmomanometry for the same practical reasons.

The machine-vision system sees:
  • pupil sizes measured to sub-pixel precision;
  • clearly the distinct pupil border between a dark iris and a black pupil in a dark environment under infrared imaging;
  • clear differentiation between pupil response asymmetry and base-line pupil size asymmetry of anisocoria; and
  • both the direct and consensual responses simultaneously,
all of which human, subjective assessments typically cannot do.

The responses video can also be played back for further assessment by the physician. The machine vision system reports in high-detail the response that is elicited and, with a test’s short series of paired responses, biological noise not attributed to the machine-administered light stimuli, is generally well-minimized from averaging.

In regard to quantification, researchers have described that a 0.3 ND asymmetry[2] could be a marker as to when the functional asymmetry may start becoming interesting or relevant, as a red flag, to potentially look deeper as to why asymmetry is present. It may be helpful to recall, in practical terms, that a 0.3 ND filter absorbs 50% of the light, a 0.6 ND -> 75%, and 0.9 ND -> 85%. With an asymmetry in which one eye’s response corresponds to a 50% reduction of light, or more, compared to the response of the fellow higher responsive eye, it feels obvious that we would want to look closer as to the nature of this marked functional difference. It will feel both surprising and logical as to how there is a spectrum of asymmetry in the patients you see each day and periodically it will be dramatic triggering some introspection as to what has passed through your office prior.

Other key aspects:
  • Glaucoma is a common condition that may cause an APD, but not all glaucoma will present asymmetrically, and as the depth of the disease increases, asymmetry decreases as total retinal function becomes significantly depressed.
  • There are many other causes of asymmetry, and may even include amblyopia that is commonly not considered. I have personal experience with this.
  • Pupil testing is not defined as an optional test for a comprehensive exam either by the AOA or AAO, but it is clear from hundreds of discussions that collection of this important physical sign is often ignored (some docs become salty in the importance of this testing after not finding very much over time), delegated with embarrassingly poor quality control, or routinely assessed with sub-optimum results. Notations of administration in patient’s record when it has been done poorly by techs or not at all can be problematic on multiple levels.
  • A machine-vision assessment can be easily administered by a technician with results that can be reviewed by the doc even after dilation. It is a tool to help you discover physical signs that routinely are missed.
  • The PLR is difficult to perform well, naturally has variability, and this can now be well measured objectively. A machine vision assessment of PLR is of course not a requirement nor are OCTs, autorefractors, fundus cameras or other technology-augmented tools, but it is uncomfortable practicing without them.
If you are very comfortable with the precision and simplicity of the APD testing you are doing and you are are regularly uncovering the asymmetry we are tasked with uncovering, great! If a technician-adminstered test that is likely much more detailed that what you can do yourself could be of value in your practice, there are interesting solutions now. You will be surprised at what you have been missing.

Best regards,
Charles Wm. Stewart, OD
CEO, Konan Medical USA, Inc.

__________
1. Satou, Tsukasa, et al. "Evaluation of relative afferent pupillary defect using RAPDx device in patients with optic nerve disease." Neuro-Ophthalmology 40.3 (2016): 120-124.

2. Tatham, A.J., Meira-Freitas, D., Weinreb, R.N., Marvasti, A.H., Zangwill, L.M. and Medeiros, F.A., 2014. Estimation of retinal ganglion cell loss in glaucomatous eyes with a relative afferent pupillary defect. Investigative ophthalmology & visual science, 55(1), pp.513-522.

From what my friend (OD, PhD) says, your machine is good for checking the pupil. I have no problem with it. In fact, I actually looked into getting one to see how it does in monitoring my neuro patients, but it is not in the budget.

What I have a problem with is the presentation of it being a specific diagnostic tool for glaucoma. I am glad you seem to support that the APD is a very nonspecific test.

I also have a very big problem with a patient being sent in for an MRI on the bases of an abnormal result from your instrument. I also have a problem with doctors seeming to use an abnormal result to go on a fishing expedition with tests and declaring how much can be made doing that.

I just want to have doctors use it intelligently in their practice. They should be educated well enough to know the limitations and what the results mean.
 
Variability of 0.31 to 0.01 is insane.
It is. I think we have pinpointed the cause to blinking. You really have to wait one second after the flash of light. Heavy blinkers, dry eye folks have more variability in results in our experience. There is some tech work involved to getting stable results.
 
From what my friend (OD, PhD) says, your machine is good for checking the pupil.

any chance to have your "friend (OD,PhD) " participate in the conversation?
 
The CEO of Konan said:

"There are many other causes of asymmetry, and may even include amblyopia that is commonly not considered. I have personal experience with this."

That is the exact thing I have been saying. The RAPD is nonspecific to glaucoma, but look at the attacks that have been directed at me. Even Adam has tried to say that I am wrong about it being nonspecific to glaucoma.
 
Mike Ware OD said: arrow_drop_up
My point being that this device might not be all that necessary or worth the price for those of us that already have an OCT with a screening function.


Did both of you come to your conclusion after viewing the Webinar?

I spent the hour viewing and actually stayed awake.;) My impression was quite different.

A great additional diagnostic tool in addition to what the speaker already has. Itt can be performed with great accuracy in a few minutes by a technician. The added information allows for differential diagnosis.

Best of all, the 10K cost is pin money for a busy practice which allows an OD to have the edge in treating patients.

Please spend the time viewing the Webinar and then come to conclusions.
I have not watched the webinar. Since you’ve seen it, is there anything in the webinar that refutes anything I’ve said? In other words, I made a conjecture on what I think typical ODs are willing to pay for a machine that tests for an APD. Is that covered in the webinar?
 
The CEO of Konan said:

"There are many other causes of asymmetry, and may even include amblyopia that is commonly not considered. I have personal experience with this."

That is the exact thing I have been saying. The RAPD is nonspecific to glaucoma, but look at the attacks that have been directed at me. Even Adam has tried to say that I am wrong about it being nonspecific to glaucoma.
I’ve never been taught or read any material that a RAPD is specific for glaucoma. Is that what is being asserted?
 
Seems like a few have bought the instrument and have reported on some clinical finds.
I think it would be great if those continue to report and give follow ups...

ie...What happened to the pt who went for an MRI? What are you eventually finding on those pts who "fail" the test?

TIA
 
The CEO of Konan said:

"There are many other causes of asymmetry, and may even include amblyopia that is commonly not considered. I have personal experience with this."

That is the exact thing I have been saying. The RAPD is nonspecific to glaucoma, but look at the attacks that have been directed at me. Even Adam has tried to say that I am wrong about it being nonspecific to glaucoma.

I said nothing of the sort. If you watch LCT's presentation (have you watched the presentation?), you'll see that he reviews cases of RAPD that *aren't* due to glaucoma -- he discusses MS and other conditions that are picked up as well.
 
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I said nothing of the sort. If you watch LCT's presentation (have you watched the presentation?), you'll see that he reviews cases of RAPD that *aren't* due to glaucoma -- he discusses MS and other conditions that are picked up as well.
You said I was wrong when I said the RAPD was too nonspecific to diagnose glaucoma.
 
Konan does not / has not asserted that asymmetry is specific to Glaucoma. Glaucoma is a condition with relatively high prevalance that may (not will) cause an APD. There are a plethora of other conditions that cause APDs, that include important and life-threatening conditions. I dare say a travesty if we are not carefully assessing this required physical sign. Does not have to be with an automated device.

Glaucoma not infrequently presents early on asymmetrically. Pupil responses, that we are obligated to check and document, can be a red flag that should cause us to explore further as to why one eye's summated response is seeing less light. Again consider practically that a 0.3 ND difference approximates a loss of half of the light response. Higher asymmetry should raise the suspicion level to look harder. This is the case whether it is subjectively assessed with a swinging flashlight test or with an objective machine-vision system. It is important to note that a 0.3 ND difference is clinically both difficult to assess by good observers and is routinely missed. We are confident higher ND asymmetries are also routinely missed with the subjective SFT. If the amount of asymmetry is mildly suspect (whether with a SFT or objective device), and there are no other signs, should be documented and reviewed again at an appropriate interval to look again. Having a detailed, quantified record from which to compare future results also may well serve the patient.

There is a rather famous quote that goes something like, "it used to be that gonioscopy took the prize for the test that is routinely done the worst, this now belongs to pupil testing." I forget the attribution, and the mileage may very per doc, but I am confident that adequate pupil testing needs a lot of help in eye care, emergency care, sports medicine and elsewhere. An objective assessment that is exquisitely detailed that your tech can perform for you, has a real place in many offices. if you are confident in the consistency and sensitivity of your routine pupil-testing skills including quantification, a flashlight can suffice. A magnified flashlight test also can be considered. Objective assessments often are clinically helpful and objective pupillometry is now a real tool to help us more thoroughly explore our patient's conditions.

You may also want to check out the feature that measures no-light (~scotopic) and bright-light (~photopic) pupil sizes. May be helpful to better understand if the various geometries of optic zone sizes of multi-focal lenses (CL or IOL) are well enough matched to the patient's pupil dimensions.
 
Dr. Stewart,

Is the face cup / faceplate replaceable? And are they available or will be available in the future? I can tell from using the Optos that will need replacement in a few years and my EyeKinetix user manual says the are no user serviceable parts. This is of concern to me. I would highly recommend replaceable faceplates if you have not considered it because with repeated cleaning and patient facial oils and makeup it will need replacement.

Also is the face cup / faceplate made of latex? I would be concerned about patients with latex sensitivities if that is the case.
 
I have not watched the webinar. Since you’ve seen it, is there anything in the webinar that refutes anything I’ve said? In other words, I made a conjecture on what I think typical ODs are willing to pay for a machine that tests for an APD. Is that covered in the webinar?
Paul, my conjecture is about what I think most optometrists will spend, not the value of the Eyekinetix. You know we are cheap asses. :)
 
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Paul, my conjecture is about what I think most optometrists will spend, not the value of the Eyekinetix. You know we are cheap asses. :)

As with many things optometric there is the 80/20 rule. Only 20% will watch the webinar. From that group 20% mightl consider a purchase.
 
A better attribution from above:

“The biggest problem with RAPD testing is that eyecare providers don’t do it ... I estimate that pupillary testing is documented only about 10% of the time. It used to be gonioscopy took the prize for being done seldom and badly ... ”

Lankaranian, Spaeth et al 2007

 
The new glaucoma procedures require surgical gonio lenses. If only we could put our patients under a local before doing gonio EVERYONE could get their $12.

:)

LOL--count me in. Provided that they are not on an Medicare Disadvantage plan. :D
 
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