Author Topic: Science and Statistics -- supporting Todd's success.  (Read 7127 times)

Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #15 on: February 06, 2012, 05:45:26 PM »
Subject:  I am following the reviews posted by Jansen and Peter -- and the success of Todd.

The reason why an OD LOVES that minus lens is that he can impress everyone with it.  That is perfectly understandable.  You don't have to argue or discuss ANYTHING with the poor patient.

But equally, I am never going to be a "patient" of such an arrogant OD -- ever again.  This is why, even though I "restrict" what I might claim, I always insist that the person understand this issue of the minus lens and why it is used, and often profoundly over-prescribed.

Yes, people are different.  But I do attempt to supply the rationale for the anti-prescription lens.  It does make logical and scientific sense.  This is why I attempt to empower the person to 1) Make certain he has his own Snellen (visual acuity chart) on the wall, to confirm he passes these DMV requirements (from 20/60 to 20/40) and sufficient expertise to have two "test" lenses to confirm the minimum minus needed to "just clear" the 20/20 line.

I advocate this as a matter of personal wisdom, and scientific fortitude.  As even Mike says it -- he has no interest in helping even his own children with plus prevention, or ANY PREVENTION.  That only means -- I must have the personal courage, to do this work myself -- before my Snellen goes below 20/60 -- in my opinion.

Otis

Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #16 on: February 15, 2012, 05:27:19 AM »

Statement:  If we lived in an "open" environment -- our refractive status would be positive (see below).

But when we force a kid to go through 12 years of school, the ENTIRE POPULATION OF EYES starts to become NEGATIVE in refractive state.

Here is the data itself:

Title: Ocular Biometry of Eskimo Families.

Francis A. Young
George A. Leary

Primate Research Center, Washington State University
Pullman, Washington 99163

Summary of the data:

Age (Average), Eyes (Each Group), Mean, Sigma (S.D.)

Age 58 Eyes 96 Mean +2.21 Sigma 1.31

Age 39 Eyes 180 Mean +1.19 Sigma 1.55

Age 16 Eyes 194 Mean -0.93 Sigma 1.97

Age 9 Eyes 218 Mean +1.40 Sigma 1.70


+++++++++++++++++++++++++++++

The use of the plus, creates a DISTANCE environment -- if  used correctly.

This is why Todd and others have become successful.  But is does take great insight to do it correctly.

Otis


Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #17 on: February 15, 2012, 08:50:04 PM »
A statistical picture of the natural eye's responsiveness to being placed in a "cage".

This is a summary effect of "long-term" near on our natural eyes.  The wise use of the plus, (as Todd did it) can result in a gradual change of refractive status in a positive direction.  It would be good if you were informed of this possibility, at the earliest point in becoming nearsighted.

http://myopiafree.i-see.org/DynamicEye.html

Tragically, few ODs will volunteer this information to you.


Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #18 on: February 23, 2012, 06:21:28 PM »
For the Todd and the group -- why wearing the plus is both justified by science and necessary,
 
(Scientific chart by Francis Young and Don Rehm.)
 
I am often asked to PROVE the wisdom and necessity of wearing the plus for prevention.
 
I am told that while a minus will CAN CAUSE MYOPIA, the plus has ‘NO PREVENTIVE EFFECT -- EVER".
 
Here is the data itself.
 
I know you can’t get a child to wear a plus “correctly”, so the kids are forced to wear a plus, by putting a minus and plus together in a bifocal. There is no other way to do this.
 
This data is over a period of five years.  These results are highly significant.  They show that the plus group – DID NOT GO DOWN. The minus went down at a rate of 0.7 diopters per year for five years.
 
This means that after five years, the child with a single-minus was a -0.7 x 5 = -3.5 diopter myope, while the kids with the plus (granted with a minus on top) stayed where they were, at –1/2 diopters, or about 20/30 if checked with your own minus lens.
 
I know that people will “object” to teaching the child to always wear a plus when they sit down to read – but there is truly no other choice, but neglect and its proven consequences for the child.
 
This is why personally wearing a minus, and checking your own Snellen in very wise.
 
http://www.myopia.org/bifocaltable4.htm
 
This data is ignored by the “conventional” OD, who says that “plus studies don’t mean anything”.  In science they do – in medicine, seemingly SCIENCE HAS NO MEANING.
 
Remember, these kids could not be taught how to use a plus BY ITSELF!
 
In my judgment, if a person is at –1/2 to –3/4 diopters (threshold) and teaches himself to wear the plus for all close work, and would check his own refractive state with his own test lens, he would measure a change in status in the positive direction, and begin to pass the 20/25 line in from six to nine months.
 
This is what, in your wisdom, you could do.
 
This shows the consequences for children – if they don’t do it.
 
When are we ever going to learn that science is “different” than medicine?

For the wise and motivated.
 

Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #19 on: February 25, 2012, 07:45:42 AM »
I am often asked by people at -8 diopters -- if they can snap themselves out of it in two weeks with a plus.  Tragically, I can't say that.  The reason is because of the long-term slow development of a negative state for the natural eye.  (When the child places his eyes in "long-term near" -- and keeps on doing that for 6 years!!

What this plus study finally shows, is that the "do nothing" and "wear a minus" group does is go down by -0.67 diopters for six year. 

http://www.myopia.org/bifocaltable4.htm

The plus group DOES NOT GO DOWN at all.  This suggests the scientific wisdom of 1) Always check your Snellen for 20/50 or better. 2) Get your own minus if necessary for $10 3) Keep on wearing the plus.  But as the down rate it -0.67 diopters per year, you can reasonably expect the "up rate" to be on the order of +0.67 to +1 diopters per year.

Here is the "habit" that these children develop when taught to 'read early'.

http://myopiafree.i-see.org/ReadDist.html

Why do children do this?  It is like asking why children "cause their obesity".  It is just a very bad habit, that the parents should be taught to "control".  It is not "reading" that produces a negative status, as much as it is the difference between reading at 21 inches (-1.9 diopters) versus reading at 6 inches (-6 diopters) or less.  The "claim" of these ODs is that reading at 4 inches (-10 diopters) for long periods of time -- HAS NO EFFECT ON THE EYE'S REFRACTIVE STATE.  So the parents are never given any advice about this specific issue and problem. 

Otis


Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #20 on: February 26, 2012, 05:14:42 PM »
Subject: How do we know that the natural eye "moves negative" from the habit of children, and the minus (while the intention might be good) does not help?

1) There is no way you can find out -- from "human experiments".  So it does take some scientific logic in the person to solve this puzzle.  First, you test the minus lens out on primates, since you don't want to CAUSE MYOPIA in the human primate eye.  Here is the scientific result, animated:

http://www.ocf.berkeley.edu/~wildsoet/images/neg_lens_induce_myopia.swf

2) OK, the eye is dynamic, and very responsive to a strong minus, but I am not convinced that the natural primate eye (our eyes) move from plus to minus if placed in long-term near for seven years.  Here again, is what science says about this "habit" of ours:

http://myopiafree.i-see.org/SaveEye.html

I hope you don't have a problem with statistical profiles, but the same NATURAL PROCESS, creates a negative state for all our eyes.  No, not 100 percent, but up to 88 percent.  You are free to reach your own conclusions about a)  the safety of putting your nose on the page for years and b) the wisdom of wearing a strong minus lens -- at the threhold -- and thinking it is not an exacerbation fact.  But

3)  For most people, it is very difficult to accept that our totally natural eyes respond in this way, and our "habits" in our modern society are creating this negative state for our natural eyes.  That is the most difficult thing to accept when you confirm your Snellen at 20/50, and your refractive state at -3/4 diopter.  Even harder to accept is the idea that ODs will not volunteer this information to us when we become slightly negative from this type of "reading habit". 

Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #21 on: February 29, 2012, 07:42:44 AM »
Dear Student,

Subject:  Calculating the significance level of the Oakley-Young
     study

     Majority-opinion ODs generally deny ANY significance for the Oakley-Young study. But the reality is that the results are highly significant. I have taken the time to go through Frank Young's "Plus", or so-called bifocal study. He stated that is results were significant -- but did not supply the calculation nor some of the data to prove how significant his results were for the large number of individuals involved in this study.  I wonder if you could review these calculations and either state your support, or supply questions about the data.

     Here are the data from the study:

Nt = 225 wearing a plus (ages from 6 to 17)

Sigma-T = I am forced to estimate this, but the Standard Deviation  (from the Eskimos) was about 1.4 diopters. ###

Nc = 192 wearing a “single minus”.

Sigma-C = Again, forced to estimate, the Standard Deviation   (Sigma) was about 2.0 diopters.  The Eskimo data is VERY   accurate.

    Here is the classic equation from statistics:


       Xt   -  Xc

Z =  ---------------------------------------------------

    Square Root of [ ( Sigma^2/ Nt ) + (Sigma^2 / Nc )   ]


Xt = 0 diopters (the Plus group did not go down)

Xc = -1/2 diopters across the 192 people in the control group.
     (the single-minus went down at a rage of -1/2 diopters per
     year, for the kids wearing the single minus.)

     After one year with 0.5 diopters difference:


      0.0 - ( -0.5 )

Z = ---------------------------------

  Square Root of [ ( 1.4^2 / 226 ) + ( 2.0^2 / 192 )]


Z =   0.5 / 0.172

Z = 2.91


Highly Significant is above Z = 2.33

     This is substantially above highly significant after one year!!  After two years:

     Z = 1.0 / 0.172

     Z = 5.82

     This is in fact “off the map” of the Probability Curve.  ***

     Please check this math, and the significance level.

     In order to plan for FUTURE studies, (with motivated pilots, for instance) it is truly necessary that they understand the real implications of this type of scientific test, and verification of the significance of these results.

     That is why selecting engineering students who know what they are doing is so essential -- and have the personal motivation to do it right!

     If we ever were to propose this type of study to the National Eye Institute, then this would be the "core" of the argument to support a preventive study or effort, with respect to educated engineers and scientists.

========================


*** Significance levels, from the text book.

"Areas Under the Normal Probability Curve"

Z is the horizontal.  The probability is the area under the curve.

Z    Probability, or significance

Z= 2.33  P= 0.01
Z= 3.08  P= 0.001
Z= 3.61  P= 0.0001
Z= 3.86  P= 0.00001


     After one year, given the number of eyes involved, the results, in terms of science, were highly significant, and  after two years, were far above Z = 3.86, and P = 0.00001.   I would expect that engineers, who had the motivation to do this  right would achieve the same scientific results.

=========================

####  Standard Deviation (Sigma) from:

"Ocular Biometry of Eskimo Familes" By Francis A. Young and George A. Leary

Group      # of Eyes   Mean   Sigma

Grand Parents   N = 96      +2.21   1.31 Diopters

Parents      N = 180      +1.19   1.55 Diopters

Older Children   N = 194

Young Children   N = 218      +1.40   1.70 Diopters   




Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #22 on: March 03, 2012, 07:59:41 AM »
Subject: The "Catch-22" of medicine -- or why no prevention study will ever be conducted.

Reference:  The use of Large N and Small N calculations. (z-table and t-Table.)

It is clear that it will take a motivated person (at 20/40) to be part of a preventive study.

Most engineers plan in advance by using current data (plus study) to project the type of success that would be possible with people who do not "fear to wear" the
plus lens.

In fact, at -2/3 diopter, a group of pilots could slowly get out of it, provided they could be part of an organized scientific program. Here are the details.

Yes there are people who are wise, and manage to "wise up" and begin the use of the preventive-plus while still at -1/2 to -1.0 diopters. (-2.3 D average) They
get out of it.

In statistics, you need a fairly large "N", for good results, but for large "N" it is very difficult to manage the people in such a study.

These calculations are for a group of engineer/pilots who are not yet below 20/50, and can be expected to have the resolve to conduct a competent preventive
study.

This is a calculation using 16 eyes, (eight people). It is an absolute minimum number.

32 eyes would be better, but this is an EXAMPLE calculation.

We know that they eye goes down -1/3 diopters for each year in collge. (Ref: Naval Academy).

We know that the natural eye goes down when you place a minus lens on it.

There is reason to expect that an eye, wearing a +2.5 diopter for all close work, will go up by about + 2/3 diopter per year.

Thus a group with an average refradtive status of -2/3 diopter could be expected to get back to 20/20 in about nine months.

The difference between the test and control groups would be 1.0 diopters. ( Xt  - Xc )

The standard deviation for this group, would be approximately 0.4 diopters.

(Calculated from a group with 20/30 to 20/60 vision, and an average refractive state of -2/3 diopters.)

Here is the EXAMPLE calculation for this very small group using large "N" equation:

Z = (Xt - Xc) / Sqrt ( Sigma^2/Nt + Sigma^2/Nc )

Z = ( 1.0 diopters ) / Square Root ( 0.4^2 / 8 + 0.4^2 / 8 )

Z = 5.0 (This is far higher "highly significant)

Z = 5.00 (Z Table = 5.00 - 4.9999) = P(0.0001)

++++++

Small "N" calculation using the t-Table

Sigma = Sqrt ( Nt * Sigma^2 + Nc * Sigma^2 ) / ( N + N - 2 )

Sigma = Sqrt ( 8 * 0.4^2 + 8 * 0.4^2 ) / ( 8 + 8 - 2 )

Sigma = 0.428 (Degrees of Freedom 16 - 2 = 14)

t = (Xt - Xc) / Sigma * Sqrt ( 1 / Nt + 1 / Nc )

t = ( - 1/2 - (+1/2) ) / 0.428 * Sqrt ( 1/8 + 1/8 )

t = 4.67

Compare with Z = 5.00 as per above.

This Exceeds P(.0005) ( 4.14 = t14 Degrees of Freedom)

These results show the probable results of a scientific preventive study, with the people who have the motivation to work on a scientific project under their control.

+++++++

The problem is that when this concept is presented to ODs -- they simply say that

"...every knows that you can not get out of myopia".

Or they insist that "engineers" don't understand statistics.

Or they say that "prevention" is not part of anything they are doing -- or anything THEY WILL EVER BE DOING.

With that logic, they say that if you ever attempted to conduct this type of scientific-prevention study, you would be "practicing medicine" -- and they can't permite you that.

Offline OtisBrown

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Re: Science and Statistics -- supporting Todd's success.
« Reply #23 on: April 03, 2012, 06:22:24 AM »
Dear Ophthalmologist,
 
I think you will enjoy this statement by two optometrists.  They so totally believe in the minus, that they make even their own children myopic. (And I am certain, their own grandchildren.
 
This was the very difficult “problem of understanding” that I had with these ODs.
 
+++++++
 
Optometrist 1>  Also, any health professional DOES NOT go through YEARS of training because we want to get out and "dup people". We work hard and take oaths to proudly uphold standards of care to HELP people. My whole family is myopic and need glasses or contacts to see clearly in the distance. My father also had a lazy eye when he was younger. I joined the profession because I wanted to help others and educate them on their eye conditions. I LOVE and take PRIDE in helping people everyday!
 
 
Optometrist 2> This Gives me Hope due to the Fact that i will be taking me ABO in May and have been in the Optical field for over 9 1/2 years but my PASSION, i would say is the same as yours....Thank You for Your INSPIRING comment! K.U.T.G.W.
 
 
OD and family> ...to proudly uphold standards of care to HELP people. My whole family is myopic and need glasses or contacts to see clearly in the distance.

Plus-prevention advocate> So this is indeed the ethics of "lock-step" march in to serious myopia. That is indeed ethical, but totally blind to the POSSIBILITY to prevention at the "pseudo-myopia" (i.e., 20/30 to 20/60, -1/2 to -1 diopter) as described by Dr. Kaisu Viikari. As always, honest disagreement is the root of discovery in  science.

+++++++++

It is hard to mount an plus-prevention study, when all the ODs think that plus prevention is 1) A big joke, and/or 2) Anti-scientific.

These ODs spend $150,000 over four years for their training.  They don’t want to believe that there is little or no objective science to support what they have been taught.

But I do acknowledge how difficult it is to deal with the general public, when you can impress the public with a strong minus lens in 15 minutes.