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Visual Contrast Sensitivity - Can You Really Measure Your Mould Disease Burden This Way?

Uncategorized Feb 08, 2020

Today I'm going to be talking about visual contrast sensitivity testing, also known as VCS tests and for today's presentation I've decided to wear this very loud jumper and it's going to make sense to you in a few minutes. We are talking about the ability of your visual system to tell the difference between different shades of gray and this is really, really, really important and essentially this whole field of visual contrast sensitivity testing is increasing in the minds, especially of those persons who have been exposed to water damaged buildings because it is being increasingly used by healthcare providers and clinicians and also people who can go online and do their own testing to see whether or not they show deficits in their visual acuity according to contrast sensitivity.

And I'm going to be going through some of the foundation principles of this test, some of the areas where this has been used, what its history is, who first developed it and more recently leading into its correlation with water damaged buildings and exposure to mould and also some of the other health issues which are correlated with visual contrast sensitivity.

And then we're going to have a bit of a discussion about how this is of benefit to you and then we are going to go through the method of how you actually carry out visual contrast sensitivity testing and we'll be using the manual method rather than the online version. And so we're going to be using a couple of different cameras today. So bear with me while I get all of them on. But to begin we are going to go through a bit of a presentation because it is important to talk about some of the principles and everyone wants to know, especially when I go out on site to do water damage and mould investigations, many people have already done their own visual contrast sensitivity testing or they have failed this particular test when they've gone to their healthcare practitioner and they're very worried about whether or not their water damage building is in fact impacting on their health and more importantly whether or not this test that is claiming to pick up neurological deficits is in fact demonstrating that they have been exposed to mould.

But how does VCS testing work? Well it is based on the ability of your eyes to differentiate different shades of gray and Mary Kay, thanks for jumping on with your question. That's very interesting that you said it confirmed your suspicion based on your history and look, I wish you will on your recovery to water damaged building exposure, but this just shows you that there is a lot of interest in self testing that you can carry out or tests that your healthcare practitioner can carry out and essentially it's quite straight forward. You need to be able to differentiate the levels of contrast between black and white. And importantly, down the bottom you can see that the test uses, in a sense, if you're unsure whether or not the bars are going up and down or whether they're facing the left or the right, and that's just a simple test image.

Now again, I go out to many different buildings to do water damage and mould investigations and a couple of months ago a clinician rang me up and said, "Can I go out and test this particular lady's home? She's in severe, she's having a whole bunch of health issues." The first thing she did was she opened the door. She said, "I want to show you the mould." I always take a history and do a thorough visual inspection of the home. But she asked me to come into a bedroom where the mould was unfortunately particularly bad, and she said, "I want to show you the results of my VCS testing."

And I said, "Look, I have seen them before, but please explain to me." And she had a whole range of different VCS testing results taken over the last several months and she said that she's used this data to inform her housing authority about the dire straits that her property is in and yet in a sense they have just cast aside these results and and are not particularly interested. And that's one of the motivations why I wanted to make this particular video today because I know that there are many people out there who are using VCS testing to in a sense determine whether or not it is more probable that they have been exposed to some sort of hazardous situation. But I also want to emphasize that VCS testing is used for a whole bunch of different health problems as well.

Now what is it? Well essentially it is a way of testing how your visual system detects different shades of gray. That is between the extremes of black and white. The ability to distinguish black and white was originally a motivating factor in the development of VCS testing, which was originally developed by the military and it was to assess air force pilots for their ability to find targets and obviously that would have a whole bunch of benefit to the army.

And the original work was carried out by someone called Dr Arthur Ginsburg and he pioneered the test or the use of visual contrast sensitivity for the Air Force Office of scientific research. And for anyone who is interested in the foundation principles of how this test was used and what the original data is, a lot of it has been unclassified and you can find it online. That's very interesting reading.

Now, some more background about this, more recently Dr Richie Shoemaker who has been a pioneer in the investigation of water damaged buildings, and importantly the correlation of those persons with these adverse building environments and the fact that many of these adverse building environments have mycotoxins or mould in high levels, and then the exposure of persons to these mycotoxins then seems to show a connection with deficits in their visual system.

And certainly Dr Shoemaker has been a champion of VCS testing for identifying those individuals that might show neurological changes in their visual system. Now in a sense, this is really important to note. However, there are a whole bunch of other groups of people that also benefit from VCS testing because it wasn't really designed only for highlighting those individuals that might have been exposed to mycotoxins. But before we move on to quite a long list of adverse health issues that can be picked up using VCS testing, I want to highlight some of the key papers which again I urge you to look up on Pub Med yourself, which indicate at least to Dr Shoemaker that there was a connection between exposure to toxins and adverse results on VCS testing and some of his original research was the exposure of people to a marine toxin. So this is not a mould toxin, but it is another environmental toxin which shows a very clear correlation with deficits in the VCS testing results.

And again, he's done some other great research on this as well, which you can find online. Now in 2010 the NIOSH published a fantastic document showing the correlation with a whole bunch of workplace exposure to water damage building and visual deficits in their employees. And this document is mandatory reading for anyone who is interested in VCS testing. And it definitely clearly makes a good case for the connection between VCS testing and being able to identify those individuals that have been exposed to mycotoxins and water damaged buildings. However, as a scientist, I need to present a balanced viewpoint here and it is important to realize that VCS testing was certainly, as I said, designed for a whole range of psychophysics testing of individuals. And there's new research showing that even the consumption of chocolate can impact on your visual system to differentiate these different shades of gray. So just bear this in mind that VCS testing should not be considered as a primary diagnostic for persons exposed to water damaged building interiors.

Now I want to present a short list or it's quite long list actually of different health impacts which have been connected with VCS testing and this is very clear in the literature so those persons who have Alzheimer's or show Parkinsonian type symptoms show deficits in their VCS testing results. Those who have depression also showed differences in their results. Those who are suffering from HIV or Acquired Immunodeficiency Syndrome showed profound differences in contrast sensitivity. The elderly, this is a particularly important group because if there is a way to screen the elderly for the likelihood that they might have a fall. Obviously if you're not able to detect edges or see a a shape contrast, well that has a connection with your ability to do trip hazard reduction so VCS testing is certainly of use there.

Now those who are have glaucoma or diabetes related eye conditions also would benefit and do benefit from VCS testing and age related macular degeneration and cataract is another group as well and blood pressure. Differences in blood pressure can also impact on the retinal system and obviously your ability to discriminate shades of gray. The list does go on. Again, exposure to organic solvents, workplace problems and especially those workers who in commercial laundries or exposed to dry cleaning chemicals, show quite profound differences in their VCS testing results as do those who are exposed to heavy metals such as lead or mercury. Now those who are exposed to Sick Building Syndrome. That document and I put up on the screen before is a particularly well-written example of the evidence linking worker exposure to unsafe workplaces and deficits in the visual system and chronic biotoxin associated illness.

"Sirs" is increasingly the terminology or catch-all framework for those individuals that are seeing an immune response and now the connection that Dr Shoemaker and other clinicians are finding with their patients is that VCS testing is a useful method to add to their approach of persons when they suspect that the environment might be causing illness. Obviously driver assessments are a useful subgroup of people who would benefit from VCS testing and it can also detect those who are are currently abusing alcohol and similarly it is also been used to identify those individuals that may have schizophrenia.

So you can see that it is quite a huge group of people who show visual acuity changes over their lifetime and when they are suffering various different health related problems. But how do you actually go about doing VCS testing? Well, there are a range of different service providers that can do this online for you. Visual contrast sensitivity tests usually are presented in a graphical format. In a few minutes I'm going to go through Dr Shoemaker's manual method.

However, there is a whole range of different online tests that you can do. We have our own and these are the types of graphs that are produced, showing a couple of different things. Usually the color of the circles indicates the correct answer being green, red indicates a incorrect answer and depending on which rows or your ability to differentiate these shades of gray, you either pass or fail this test. But in order to make this clear, we are going to use the manual method today and this is the original Dr Shoemaker method, which is very good because being a manual test, you can see how the results add up one test component at a time to a final answer, which indicates whether or not your VCS testing is good or bad for that particular eye.

So how do you do this VCS testing manually? Well, it's easy. It's not exactly like a maths test, although there is a right or wrong answer. You don't have to do any calculations. All you have to do is work out whether or not the bars are horizontal moving to the left or moving to the right. You have to do one eye at a time. And in a sense it's a bit of a game. So it should be approached like that. The intention is that your clinician may or yourself, if you're doing the test online at home, you want to test your VCS over a period of time to see whether or not, say mould avoidance or mould remediation or moving environments has an impact on your VCS testing.

So before we move to the next camera and we go through some of the manual methods so I can actually demonstrate this in practice, I want to say what's in it for you. Well, you should certainly consider this test if you think that you have been exposed to mould or mycotoxins. It is a noninvasive test, which obviously means it's easy, it's certainly inexpensive and reasonably quick to perform. It potentially screens for various different health conditions. So bear this in mind that even if your objective is to work out whether or not biotoxins might be a significant impact in your life and wellbeing, it is not a diagnostic criterion. So it is a test in a sense, it is to assist in your healthcare journey in this particular case, if you are suffering from mould exposure.

It definitely does allow you or your clinician to track your progress over time. And that is a great thing because in all risk management you want to monitor the situation over time to see whether it gets better. And VCS testing is an ideal simple test that you can use to see whether or not the interventions that you might do into your home or workplace are being effective and actually changing the physiological outcome if that is what you're after.

And importantly, and certainly I speak to so many people who have done this test and they all say to me that it has allowed them to confirm that something is or was wrong and importantly it's allowed them to show that it's not all in your or their head. And this is really, really fundamental and important because this impacts on mood, impacts on depression, it impacts on how you feel about the fact that you might have an adverse health issue happening due to an environmental toxin. And so I really like VCS testing and I recommended it simply because it is useful, simple, cheap and effective.

Now what we're going to do is I'm going to now move over to... Another camera. Okay. And while I do that, I'm going to hand this to you, Derek. And I'm going to now move this back and I want to show a few things, firstly. Doctor Shoemaker's manual test for VCS testing comes with this... in a sense, this contraption. And what is included in here is that you can actually push this onto your chin. You can put various different tests, cards, which in this situation you need to be able to work out whether or not the person is suitable for this.

Now I wear glasses. Obviously I'm a scientist, I'm not a medical doctor, so you need to consult your healthcare practitioner that actually do this. But I wanted to purchase this so I could do the tests myself. Like I could actually see whether I've been exposed to mould and mycotoxins, which obviously I have been because this is my profession. I do a water damage and mould inspections. Now Dr Shoemaker is very clear that you need to have adequate visual acuity before you actually do this test.

Now the test kit comes with an eye patch because you need to test one eye at a time. For the sake of today's demonstration, I'm not going to put the eye patch on. What I want to highlight is that it comes with this card. Now this card really is the most important component of the VCS test and you'll see that there is a grid labeled A to E across the top and then one to nine down the side and you can see that there are a range of different bars in gray and we're really, really interested in the ability of your left and right eye to actually discriminate the orientation of these bars. So your clinician, we'll be using this type of test card and they'll ask you to put this together. And Derek, if you can zoom out a little bit, then essentially with one eye covered, the clinician would be recording the results on here. You would start, A1 and you would say, "Those bars are going up to the left." A2, up and down. A3, to the right, and you would progress down these columns and that would be recorded on this test card.

Now, Dr Shoemaker's work has shown the deficits in columns C and D are good indicators for biotoxin exposure. And so what I'm going to do is I'm going to put this down now. I'm going to pull up what happens when I actually did this on myself. Now I wanted to see how my left and right eye... What the results were and in order to work this out, what I did is that I took my glasses off and immediately I started to fail some of the columns in C and D.

And so I could see that it was just impossible to differentiate the bars, where when I put my glasses on, I don't have the gene from old exposure. So this might not be the most suitable test for me, but I wanted to see what would happen when I was just unable to see these gray things. And really it's quite humbling when you're actually doing the test and you can't work out whether they're up and down, left or right. And so you just can't get the right answer if you can't see and do that contrast sensitivity. So that's like a really interesting test. And so I recommend visual contrast sensitivity testing for all the reasons that I've summarized before. It's quick, rapid, it allows you to monitor over time and you can actually see how the results build up. And there's some really elegant science underpinning all of this.

So if you're at all concerned about exposure to mould and biotoxins and whether or not this has had any impact on neurological symptoms or problems that you might be concerned about, well consider VCS testing. Anyway, thanks for tuning in this week. I look forward to talking to you and taking any of your questions, which I will answer in the comments below. And thanks for watching and make sure to like this video and share it and I'll see you next week at 11:00 AM. Bye for now.

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