Scientists state that pseudo-myopia leads to axial myopia.

Dear Prevention-minded freinds,

There are two opinions about the prevention of myopia:

The second-opinion, that on the threshold, if you could prevent
incipient myopia before a minus lens is applied, you could
prevent axial-myopia. Or, prevention is always impossible.

Here is an analysis provided by Alex Eulenberg for
your interest.

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

Vision scientists George Hung (Rutgers Dept. of Biomedical
Engineering) and Kenneth Ciuffreda (SUNY College of Optometry) are
claiming that the "temporary" blurry distant vision that comes from
reading too long, too hard, is a step on the way to permanent myopia.

This may seem obvious to many of us, but then again, there are many in
the eye care profession who would deny this, or at least express the
opinion that there is room for doubt.

The article is "Incremental retinal-defocus theory of myopia
development-Schematic analysis and computer simulation" (in press)

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra\
ctPlus&list_uids=17150204&query_hl=1&itool=pubmed_docsum

"In addition, the theory has been able to explain how repeated cycles
of nearwork-induced transient myopia leads to repeated periods of
decreased retinal-image defocus, whose cumulative effect over an
extended period of time results in an increase in axial growth that
leads to permanent myopia."

I must admit, since I have not read the article, that I am at a loss
as to what these two mean by "decreased retinal-image defocus," but it
is of little matter. What is striking here is the confidence in the
way the authors present their theory. These are two prominent vision
scientists and co-authors of a vision science textbook ("Models of the
Visual System"). They are staking their reputations on the existence
of a causal chain from near work to temporary myopia to permanent
myopia. No "may lead" or "could result" here. I think this is a
significant moment in the history of vision science.

Alex

 

Otis's and everybody else's.

Gee, Otis. A theory. How marvelous.

YOU, too, have a theory. Unfortunately, it fails to hold up in HUMAN
clinical trials AND it induces DOUBLE VISION in people naive enough to
listen to you.

Let's go back ... once again ... to Scientific Method 101 for Dummies
like yourself:

Recognize the problem

Observe the problem

Formulate a hypothesis (this is as far as you've ever gotten)

Devise and conduct experiments to test the hypothesis (using the
results of this testing to inform and revise your hypothesis. You
seem to detest this part)

Come to a conclusion based on the testing.

Hurting unsuspecting people (or the children of desperate parents),
helping nobody (ask your myopic niece), mangling statistics, and
occasionally throwing out Greek letters doesn't make you a scientist.

Not even close.

 

Dear Neil,

Since you are un-employed, and have a lot of free time
on your hands, you might enjoy reading further analysis
of this issue by Dr. Hung. See:

http://www.worldscibooks.com/engineering/4652.html

Also, Alex Eulenberg is the author of

www.i-see.org

for the enhancement of vision.

Otis

 

Never let the facts get in the way of a good story, Otis.

Why don't you make THAT your permanent Usenet signature?

 

Who friggin' cares! do you think that statement is some kind of
credential that builds credibility? that website is a bunch of
"alternative medicine" freaks (and thats being kind) who believe all
sorts of wacky unproven notions.

 

Now that Otis has discovered this article by Hung and Ciuffreda, I am
eager to see where he goes with it. I must say that quoting Alex
Eulenberg -- who himself has not read the article, is not a very
encouraging sign.

Otis and Alex have now taken hold of the proverbial rope. Let's see
just how long it will take them to hang themselves with it.

DrG (who has read the entire article)

 

Well, I'm waiting for Otis to read the study so he can tell us just how
it supports his paradigm. This should be good.

DrG

 

Dear Prevention minded friends,

Subject: Professor Hung's theory -- simplified.

In order to understand this "de-focus" theory, you
should review the animation of it produced
by Dr. Wildsoet on:


http://vision.berkeley.edu/wildsoet/myopiaprimer.html


What the theory predicts is that if you place
a -3 diopter lens on the eye, it will change its
refractive STATE by -2 diopters in six months.

[See the refractive change on the blue-tinted
eye on this site.]

Here is Dr. Hung's verbal description of that proven
process the eye uses to control its refractive STATE.


Best,

Otis

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

A unifying theory of refractive error development.

Hung GK, Ciuffreda KJ.

Department of Biomedical Engineering, Rutgers University, 617
Bowser Road, Piscataway, NJ 08854-8014, USA.



While retinal defocus is believed to be myopigenic in nature,
the underlying mechanism has remained elusive.

We recently constructed a theory of refractive error
development to investigate its fundamental properties. Our
Incremental Retinal-Defocus Theory is based on the principle that
the change in retinal-defocus magnitude during an increment of
genetically-programmed ocular growth provides the requisite sign
for the appropriate alteration in subsequent
environmentally-induced ocular growth.

This theory was tested under five experimental conditions:
lenses, diffusers, occlusion, crystalline lens removal, and
prolonged nearwork.

Predictions of the theory were consistent with previous
animal and human experimental findings. In addition, simulations
using a MATLAB/SIMULINK model supported our theory by
demonstrating quantitatively the appropriate directional changes
in ocular growth rate. Thus, our Incremental Retinal-Defocus
Theory provides a simple and logical unifying concept underlying
the mechanism for the development of refractive error.

PMID: 11127515 [PubMed - indexed for MEDLINE]


Ghung8.txt

Incremental retinal-defocus theory of myopia
development-Schematic analysis and computer simulation.

Hung GK, Ciuffreda KJ.

Department of Biomedical Engineering, Rutgers University,
Piscataway, NJ 08854, USA.

Previous theories of myopia development involved subtle and
complex processes such as the sensing and analyzing of chromatic
aberration, spherical aberration, spatial gradient of blur, or
spatial frequency content of the retinal image, but they have not
been able to explain satisfactorily the diverse experimental
results reported in the literature.

On the other hand, our newly proposed incremental
retinal-defocus theory (IRDT) has been able to explain all of
these results. This theory is based on a relatively simple and
direct mechanism for the regulation of ocular growth.

It states that a time-averaged decrease in retinal-image
defocus area decreases the rate of release of retinal
neuromodulators, which decreases the rate of retinal proteoglycan
synthesis with an associated decrease in scleral structural
integrity.

This increases the rate of scleral growth, and in turn the
eye's axial length, which leads to myopia.

Our schematic analysis has provided a clear explanation for
the eye's ability to grow in the appropriate direction under a
wide range of experimental conditions. In addition, the theory
has been able to explain how repeated cycles of nearwork-induced
transient myopia leads to repeated periods of decreased
retinal-image defocus, whose cumulative effect over an extended
period of time results in an increase in axial growth that leads
to permanent myopia.

Thus, this unifying theory forms the basis for understanding
the underlying retinal and scleral mechanisms of myopia
development.

PMID: 17150204 [PubMed - as supplied by publisher]

==========

 

No it doesn't. You didn't read the paper. The abstract is misleading.
Read the paper before you start, because when you do, you will be
embarrassed that you wrote the above.

DrG

 

I seem to recall trying to lead him through one of Cuiffreda's models
before.

 

Effcorr.txt


Subject: The Effects of "Corrective" Lenses: Insight and
Comment From Eye Doctors

Mike> If the theory predicts it, and it doesn't happen, what does that
mean?

Mike, it means your believe that the natural eye is NOT dynamic,
and that a minus lens has NO EFFECT on the refractive STATE
of all natural eye -- against the objective scientific facts. And that
is your majority-opinion.

The second-opinion recognizes the fact that no clinical or
statistical studies have ever demonstrated the
long-term safety of a (minus) "corrective" lens.

In fact, a certain percentage of doctors believe that -- as the
second-opinion -- "corrective" lenses (also known as
"compensatory" negative lenses) usually create dependency and
make the eyes move more rapidly in a negative refractive direction.

These concerns have been voiced in the professional
literature by concerned doctors who support the concept
the "second opinion" to do work for the prevention of nearsightedness
with a plus lens.

Here are sample excerpts from the professional literature voicing
concerns about the safety of "corrective" lenses:

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

"The use of compensatory lenses to treat or neutralize the
symptoms does not correct the problem. The current education and
training of eye care practitioners discourages preventive and
remedial treatment." R.L. Gottlieb, Journal of Optometry and
Visual Development, 13(1):3-27, 1982.

"The emphasis on compensatory lenses has posed a problem for
many years in our examinations. These lenses do not correct
anything and may not serve the patient in his best interests over
a period of time." CJ. Forkiortis, OEP Curriculum, 53:1, 1980

"There are frequently ignored patterns of addiction to minus
lenses. The typical prescription tends to overpower and fatigue
the visual system and what is often a transitory condition becomes
a lifelong situation which is likely to deteriorate with time." S.
Gallop, Journal of Behavioral Optometry, 5(5):115-120, 1994

"Single-vision minus lenses for full-time use produce
accommodative insufficiency associated with additional symptoms
until the patient gets used to the lens. This is usually
accompanied by a further increase in myopia and the cycle begins
anew." M.H. Birnbaum, Review of Optometry, 110(21): 23-29, 1973.

"Minus lenses are the most common approach, yet the least
likely to prevent further myopic progression. Unfortunately, they
increase the near-point stress that is associated with
progression." B. May, OEP Publications, A- 112, 1984.

It seems that Professor Hung's concept of the dynamic
eye is closer to scientific truth that your "belief" that
the eye does not respond to an applied -3 diopter lens.
(Over-prescribed if you like). And even the safety
of that minus is an open question at this point.

Best,

Otis

 

Dr. Tyner is simply stating his observations that his patients who wear
-3.00 D lenses do not progress to -5.00 myopes. i must corroborate
that MY -3.00D myopes also do not progress in that fashion. that does
not mean we choose to believe one theory or another theory, it is
simply a statement of our observations on our patients. if your theory
is correct, then why don't our patients behave as your theory predicts
(hint: your theory could be incorrect).

there is no such thing as your term "second-opinion". this is a phrase
YOU choose to use to describe your personal believe and it is not
supported by any evidence. you like to try to give your notions some
credibility by claiming there is a larger group of others who also
concur with you. sorry-- "second-opinion" = Otis' personal opinion and
nothing more. you are just a lonely newsgroup internet troll.

have you noticed that your supporting articles are from 20-30 years
ago? indeed some real legitimate researchers considered this theory as
plausible in the past but then something called the "scientific method"
was used to examine it and it didn't hold up to testing.

why haven't you moved on like the rest of the legitimate vision
researchers did?

do you believe the earth is flat?

while you are at best illogical and at worst psychologically ill, you
are indeed persistent!

 

This is a dynamite paper, by the way, and should appeal to any person
who calls himself an engineer. Unfortunately for Otis, it won't
support most of his ideas, especially as it pertains to the use of
strong plus for the prevention of myopia. In fact, it puts Otis into
an even tighter corner.

Remember how we have been discussing the concept of retinal defocus as
opposed to accommodation, and how Otis keeps dragging us back to the
junkheap of outdated ideas? This paper makes that even more obvious.


DrG

 

Otis won't be embarrassed. He posts the most ridiculous things without
it.